Changes in intake of plant-based diets and weight change: results from 3 prospective cohort studies

Guilt by association: Plant-based foods can be incorporated into both healthy and unhealthy plant-based diet indices associated with coronary heart disease

Background

One approach to test for differential associations between plant foods with health uses a scoring approach: foods categorized into animal or 'healthy' plant-based or 'unhealthy' plant-based groups to construct a plant-based diet index (PDI), healthy PDI (hPDI), and unhealthy PDI (uPDI).

Objective

To evaluate robustness of associations between diet indices and incident coronary heart disease (CHD) risk when recategorizing food groups in indices.

Methods

Using REasons for Geographic and Racial Differences in Stroke (REGARDS) data, we replicated a published use of the scoring approach. Using Cox proportional hazards regression, we assessed ramifications of the following on associations between diet indices and CHD risk: 1) reconfiguring foods within and among food groups, using potatoes as an example, 2) leave-one-out analysis for each of 12 plant-based food groups, and 3) agnostically redefining each food group as 'healthy' or 'unhealthy'.

Results

Over 153,286 person-years of follow-up, there were 868 cases of CHD. Replication analyses did not reach statistical significance. General patterns of magnitude of hazard ratios (HRs) in replication and reconfiguration models were PDI HRs < hPDI HRs < uPDI HRs for women, and hPDI < PDI < uPDI for men. Five models reconfiguring potatoes resulted in small, varied differences in PDI, hPDI, and uPDI associations. Leave-one-out analyses resulted in greater variation of associations between indices and CHD. In agnostic models, each plant-based food group was classified in indices as 'healthy' and 'unhealthy' with statistically significant beneficial or deleterious associations with CHD. Averaged over 4,096 models, HRs' shifts were small when food groups were moved between 'healthy' and 'unhealthy'.

Conclusion

Statistically significant associations between hPDI, uPDI, and PDI and incident CHD were not replicated. Small perturbations of the scoring approach had varied impacts on HRs. Agnostically constructing diet indices demonstrated the potential for guilt (or benefit) by association: any of the food groups we studied could be categorized with others in an index showing beneficial or deleterious associations.

A plant-based diet index to study the relation between diet and disease risk among adults: a narrative review

Plant-based diets (PBD) may offer various health benefits and contribute to a sustainable way of life, but, if not planned correctly, may also confer risks, e.g., by focusing on plant foods with low nutrient density, such as foods primarily consisting of refined carbohydrates. A plant-based diet index (PDI) differentiating between a healthful, unhealthful, and overall PBD, offers a promising approach to standardize and compare studies and integrate results. In this review we (1) summarize current evidence on the PDI and disease risk of relevance to public health, (2) discuss the methodology of the PDI and how it can be sensibly applied in further studies and (3) indicate areas with a lack of knowledge, such as vulnerable populations. In summary, our amalgamation shows, that adherence to a healthier plant-based diet is associated with an 8-68% lower risk for metabolic risk factors, diabetes, and cardiovascular disease, while adherence to an unhealthier plant-based diet is associated with a 10-63% higher risk. Although differences in calculation methods and underlying diet patterns between populations should be accounted for, the PDI can be a useful tool to assess adherence to different plant-based diet patterns and their association with health outcomes in cohort studies across cultures.

Predictors of Eating Less Meat and More Plant-Based Food in the Polish Sample

The study aimed to identify predictors of the intention to eat less meat and more plant-based foods, including attitudes towards eating meat, habitual meat eating, subjective norms, and self-identity. A cross-sectional study using CAWI (Computer-Assisted Web Interview) was conducted in a group of 1003 Polish adults in 2023. To measure the predictor variables, the following tools were used: Beliefs and Eating Habits Questionnaire (KomPAN), Meat Attachment Questionnaire (MAQ), and scales to measure subjective norms and self-identity. Logistic regression analysis was used to verify associations between independent variables, and the intentions to eat more plant-based food and less meat next year were treated as dependent variables. More respondents were willing to increase their consumption of plant-based foods rather than reduce their meat consumption. The intention to consume less meat and more plant foods was more prevalent among women, older people (only intention to reduce meat consumption), and better-educated people (only intention to increase plant food consumption). Habitual frequency of eating plant foods, negative feelings about meat, and environmentally oriented identities had a stimulating effect on the intention to eat more plant foods and less meat, while experiencing pleasure in eating meat had a limiting effect on the intention to eat more plant foods and less meat. In addition, the habitual frequency of meat consumption and subjective norms reduced the likelihood of eating less meat, while no predictive effect was observed for the intention to eat more plant foods. In conclusion, educational and promotional activities to raise awareness of the link between food consumption and the environment can have a strong impact on eating less meat and more plant-based food, even among those strongly accustomed to meat consumption.

The associations between plant-based dietary indices with depression and quality of life and insomnia among Iranian adolescent girls in 2015

Although previous research has explored the link between plant-based diets and mental health outcomes, there has been limited study on the quality levels of plant foods in this context. This study was conducted on 733 adolescent girls from cities in northeastern Iran. The validated Iranian version of the Insomnia Severity Index, SF-12v2 questionnaire and Persian version of the Beck Depression Inventory used to assess insomnia and poor quality of life (QoL) and depression, respectively. Dietary intakes assessed using a valid and reliable food frequency questionnaire. The association of scores of plant based dietary index (PDI) and poor QoL, depression and insomnia explored by binary logistic regression. The unadjusted model showed subjects in the highest quartile of healthy PDI had lower chances of insomnia than those in the lowest quartile (OR: 0.50; 95% CI 0.27-0.91, P = 0.024). The association persisted across various adjusted models. Subjects in the highest quartile of unhealthy PDI (uPDI) had higher chances of depression than those in the lowest quartile (OR: 1.83; 95% CI 1.09-3.08, P = 0.022). The significance of the association was maintained after adjusting for other confounders. A healthy plant-based dietary index is associated with a lower odds of insomnia. An unhealthy plant-based dietary index was associated to an increased chance of depression. Findings need to be confirmed by future studies.

Plant-Based Dietary Patterns and Incident Diabetes in the Atherosclerosis Risk in Communities (ARIC) Study

OBJECTIVE

Plant-based dietary patterns emphasize plant foods and minimize animal-derived foods. We investigated the association between plant-based dietary patterns and diabetes in a community-based U.S. sample of Black and White adults.

RESEARCH DESIGN AND METHODS

We included middle-aged adults from the Atherosclerosis Risk in Communities (ARIC) study without diabetes at baseline who completed a food-frequency questionnaire (n = 11,965). We scored plant-based diet adherence according to three indices: overall, healthy, and unhealthy plant-based diet indices. Higher overall plant-based diet index (PDI) scores represent greater intakes of all plant foods and lower intakes of animal-derived foods. Higher healthy plant-based diet index (hPDI) scores represent greater healthy plant food intake and lower intakes of animal-derived and unhealthy plant foods. Higher unhealthy plant-based diet index (uPDI) scores represent greater unhealthy plant food intake and lower intakes of animal-derived and healthy plant foods. We used Cox regression to estimate hazard ratios (HRs) for incident diabetes (defined according to self-reported diagnosis, medication use, or elevated blood glucose) associated with each index.

RESULTS

Over a median follow-up of 22 years, we identified 4,208 cases of diabetes among subjects. Higher PDI scores were associated with a lower risk of diabetes (quintile 5 vs. 1 HR 0.89 [95% CI 0.80, 0.98]; Ptrend = 0.01). hPDI scores were also inversely associated with diabetes risk (quintile 5 vs. 1 HR 0.85 [95% CI 0.77, 0.94]; Ptrend < 0.001). uPDI scores were not associated with diabetes risk.

CONCLUSIONS

A dietary pattern that minimizes animal-derived foods and emphasizes plant foods may reduce diabetes risk.

Adherence to Healthy and Unhealthy Plant-Based Diets and the Risk of Gout

Importance

Plant-based diets are increasing in popularity due, in part, to their health benefits for selected cardiometabolic diseases as well as favorable environmental impact. Little is known about how such a diet is related to gout risk.

Objective

To examine associations between adherence to a plant-based diet (including healthy and unhealthy versions of this diet), as well as its 18 individual food groups, and incident gout.

Design, Setting, and Participants

This prospective cohort study used data from population-based cohorts of US men and women enrolled in the Health Professionals Follow-Up Study (1986-2012) and Nurses' Health Study (1984-2010). Participants were men and women free of gout at baseline. Statistical analyses were performed over March 2020 to August 2023.

Exposures

An overall plant-based diet index (PDI), as well as healthy (hPDI) and unhealthy (uPDI) versions of this index that emphasize healthy and less healthy plant-based foods, respectively. These diet indices were comprised of 18 food groups, assessed using a validated semiquantitative food frequency questionnaire.

Main Outcomes and Measures

Incident cases of gout that were confirmed with a supplementary questionnaire to meet the preliminary American College of Rheumatology survey criteria for gout. Cox proportional hazards regression models were used to evaluate multivariable-adjusted associations of all 3 PDIs with incident gout using quintiles (Q) of adherence.

Results

Among a total of 122 679 participants (mean [SD] age, 53.8 [9.8] years among 43 703 men; mean [SD] age, 50.9 [7.2] years among 78 976 women) over 2 704 899 person-years of follow-up, 2709 participants experienced incident gout. The overall PDI was not significantly associated with gout in either cohort (Q5 vs Q1 pooled hazard ratio [HR], 1.02 [95% CI, 0.89-1.17]; P for trend = .63). In the pooled analysis, hPDI was significantly inversely associated with risk of gout (Q5 vs Q1 HR, 0.79 [95% CI, 0.69-0.91]; P for trend = .002), while the uPDI was positively associated with risk of gout (Q5 vs Q1 HR, 1.17 [95% CI, 1.03-1.33]; P for trend = .02), particularly in women (Q5 vs Q1 HR, 1.31 [95% CI, 1.05-1.62]; P for trend = .01). In analysis of individual food groups, higher intakes of certain healthy plant foods, such as whole grains (pooled HR per 1 serving/d, 0.93 [95% CI, 0.89-0.97]) and tea and coffee (pooled HR per 1 serving/d, 0.95 [95% CI, 0.92-0.97]), as well as dairy (pooled HR per 1 serving/d, 0.86 [95% CI, 0.82-0.90]), were independently associated with a lower risk of gout, while selected unhealthy plant foods, such as fruit juice (pooled HR per 1 serving/d, 1.06 [95% CI, 1.00-1.13]) and sugar-sweetened beverages (pooled HR per 1 serving/d, 1.16 [95% CI, 1.07-1.26]) were associated with increased risk of gout.

Conclusions and Relevance

The findings of this prospective cohort study of PDIs and gout support current dietary recommendations to increase consumption of healthy plant foods while lowering intake of unhealthy plant foods to mitigate gout risk.

Association between plant-based diets and the risk of coronary heart disease predicted using the Framingham Risk Score in Korean men: data from the HEXA cohort study

OBJECTIVES

This study investigated the potential correlation between 4 plant-based diet indices and the predicted risk of coronary heart disease (CHD) in Korean men using the Framingham Risk Score.

METHODS

The study included 12,356 men participants (aged ≥40 years) from the Health Examinees Study. Dietary intake was estimated using a validated food frequency questionnaire. Four plant-based diet indices were measured, including the overall plant-based diet index, the healthy plant-based diet index (hPDI), the unhealthy plant-based diet index (uPDI), and the pro-vegetarian diet index. Multivariable Cox proportional hazard models were used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) for the predicted 10-year risk of CHD.

RESULTS

The study found that individuals in the highest hPDI quintile had a 19% lower risk score for CHD based on the Framingham Risk Score (model 3: HR, 0.80; 95% CI, 0.69 to 0.93; p for trend=0.010). In stratified analyses, the highest pro-vegetarian diet index was associated with a lower risk score for CHD in physically active individuals (HR, 0.74; 95% CI, 0.59 to 0.93; p for interaction=0.020). Conversely, the highest uPDI was associated with the highest risk score for CHD in those with a body mass index of ≥25 kg/m2 and a waist circumference ≥90 cm.

CONCLUSIONS

This prospective cohort study highlights the positive role of adhering to a high hPDI diet in the prevention of CHD in Korean men. Further prospective studies are needed to determine the association between various plant-based diet indices and the risk of CHD in Asian populations with different dietary habits.

Adherence to plant-based dietary patterns and anthropometric indices among primary school girls in Kerman: A cross-sectional study

The objective of the study was to evaluate the association between adherence to plant-based dietary patterns and anthropometric indices among primary school girls in Kerman. This cross-sectional study included 330 girls aged 6-12. A reliable and validated dish-based food frequency questionnaire was used to collect dietary data. Weight, height, and mid-arm circumference were measured, and z-score charts from the World Health Organization for girls between the ages of 5 and 19 were utilized. We used Satija et al. method to calculate plant-based diet index scores. After adjusting for age and energy, participants in the higher tertile of the overall plant-based diet index (PDI) had a lower height-for-age z score (HAZ) (0.38±0.12 vs. 0.59±0.12 kg; P = 0.033). Higher unhealthful plant-based diet index (uPDI) scores were significantly associated with decreased HAZ in models 2 (p = 0.028) and 3 (p = 0.035). A higher PDI score was associated with lower odds of being underweight and overweight, respectively (Model 1: P trend = 0.007, <0.001; Model 2: P trend = 0.010, 0.001). A significant inverse association was found between healthful plant-based diet index (hPDI) scores and underweight risk in the crude and adjusted models. (Model 1: P trend = 0.021; model 2: P trend = 0.018; Model 3: P trend = 0.031). Higher uPDI scores were associated with increased odds of being overweight and obese in all three models (Model 1: p trend<0.001; Model 2: p trend<0.001; Model 3: p trend = 0.001). We concluded that children who followed a plant-based diet had lower odds of being overweight and obese. Higher scores on the hPDI were linked to a decreased risk of being underweight, while higher scores on the uPDI were associated with an increased risk of being overweight and obese. The study suggests healthy plant-based diet may benefit children's weight and growth.

Vegan/vegetarian diet and human milk donation: An EMBA survey across European milk banks

The nutritional adequacy of human milk (HM) from vegan/vegetarian mothers has been a matter of debate, and a variety of recommendations regarding the eligibility of these mothers as human milk donors exists. According to the latest evidence, HM from vegans/vegetarians is similar in its composition to that from omnivores, however, some differences may be observed regarding vitamin B12 and omega-3 fatty acids concentrations. Maternal supplementation of these compounds has been proven effective in increasing their HM concentration. With this survey, we aimed to explore the practices currently in use in European human milk banks (HMBs) regarding potential donors following vegan/vegetarian diets. The online survey was distributed to European HMBs between January and July 2022. A total of 188 HMBs were contacted, and 118 replied (response rate 63%). Vegan and vegetarian mothers were recommended supplements of vitamin B12 to be accepted as donors in 27% and 26% of HMBs, respectively. Additional omega-3 fatty acid supplementation was required in 8% HMBs. In the remaining HMBs, these mothers were either systematically excluded or included regardless of supplementation. The dosage of the recommended supplements was extremely variable. Fifty-one percent of HMBs were following recommendations to guide their practice, national or local recommendations mainly. Great variability in European HMBs practices towards potential donors following vegan/vegetarian diets exists. Some of these practices can result in loss of donors and/or in potential nutritional deficiencies. Standardised evidence-based recommendations on this issue and their implementation in daily HMB practice are needed.

Commercial weight-loss diets, greenhouse gas emissions and freshwater consumption

BACKGROUND

Weight-loss attempts are widespread in the United States, with many using commercial weight-loss diet plans for guidance and support. Accordingly, dietary suggestions within these plans influence the nation's food-related environmental footprint.

METHODS

We modelled United States (US) per capita greenhouse gas emissions (GHGe) and water footprints associated with seven commercial weight-loss diets, the US baseline, and selected other dietary patterns. We characterised consumption in commercial weight-loss diets both via modelling from provided guidelines and based on specific foods in 1-week meal plans. Cradle-to-farmgate GHGe and water footprints were assessed using a previously developed model. GHGe results were compared to the EAT-Lancet 2050 target. Water footprints were compared to the US baseline.

RESULTS

Weight-loss diets had GHGe footprints on average 4.4 times the EAT-Lancet target recommended for planetary health (range: 2.4-8.5 times). Bovine meat was by far the largest contributor of GHGe in most diets that included it. Three commercial diets had water footprints above the US baseline. Low caloric intake in some diets compensated for the relative increases in GHGe- and water-intensive foods.

CONCLUSIONS

Dietary patterns suggested by marketing materials and guidelines from commercial weight-loss diets can have high GHGe and water footprints, particularly if caloric limits are exceeded. Commercial diet plan guidance can be altered to support planetary and individual health, including describing what dietary patterns can jointly support environmental sustainability and weight loss.

Plant-based diets and the incidence of cardiovascular disease: the Million Veteran Program

Background

A healthful plant-based diet was associated with lower risks of coronary heart disease and type 2 diabetes, and a favourable profile of adiposity-associated biomarkers, while an unhealthful plant-based diet was associated with elevated risk of cardiometabolic disease in health professional populations. However, little is known about the associations between plant-based dietary patterns and risk of cardiovascular disease (CVD) in US veterans.

Methods

The study population consisted of 148 506 participants who were free of diabetes, CVD and cancer at baseline in the Veterans Affairs (VA) Million Veteran Program. Diet was assessed using a Food Frequency Questionnaire at baseline. We calculated an overall Plant-Based Diet Index (PDI), a healthful PDI (hPDI) and an unhealthful PDI (uPDI). The CVD endpoints included non-fatal myocardial infarction (MI) and acute ischaemic stroke (AIS) identified through high-throughput phenotyping algorithms approach and fatal CVD events identified by searching the National Death Index.

Results

With up to 8 years of follow-up, we documented 5025 CVD cases. After adjustment for confounding factors, a higher PDI was significantly associated with a lower risk of CVD (HR comparing extreme quintiles=0.75, 95% CI 0.68 to 0.82, P trend<0.0001). We observed an inverse association between hPDI and the risk of CVD (HR comparing extreme quintiles=0.71, 95% CI 0.64 to 0.78, P trend<0.001), whereas uPDI was positively associated with the risk of CVD (HR comparing extreme quintiles=1.12, 95% CI 1.02 to 1.24, P trend<0.001). We found similar associations of hPDI with subtypes of CVD; a 10-unit increment in hPDI was associated with HRs (95% CI) of 0.81 (0.75 to 0.87) for fatal CVD, 0.86 (0.79 to 0.94) for non-fatal MI and 0.86 (0.78 to 0.95) for non-fatal AIS.

Conclusions

Plant-based dietary pattern enriched with healthier plant foods was associated with a substantially lower CVD risk in US veterans.

Low-Carbohydrate Diet Macronutrient Quality and Weight Change

Importance

The associations of low-carbohydrate diets (LCDs) with long-term weight management remains unclear, and the source and quality of macronutrients within LCDs are less explored.

Objectives

To prospectively examine associations between changes in LCD indices and weight change among US adults.

Design, Setting, and Participants

This prospective cohort study included initially healthy participants at baseline from the Nurses' Health Study (NHS; 1986-2010), Nurses' Health Study II (NHSII; 1991-2015), and Health Professionals Follow-up Study (HPFS; 1986-2018). Data analysis was performed between November 2022 and April 2023.

Exposures

Five LCD indices were examined: (1) a total LCD (TLCD) emphasizing overall lower carbohydrate intake; (2) an animal-based LCD (ALCD) that emphasized animal-sourced protein and fat; (3) a vegetable-based LCD (VLCD) that emphasized plant-sourced protein and fat; (4) a healthy LCD (HLCD) emphasizing less refined carbohydrates, more plant protein, and healthy fat; and (5) an unhealthy LCD (ULCD) emphasizing less healthful carbohydrates, more animal protein, and unhealthy fat.

Main Outcomes and Measures

The outcome of interest was 4-year changes in self-reported body weight.

Results

A total of 123 332 participants (mean [SD] age, 45.0 [9.7] years; 103 320 [83.8%] female) were included in this study. The median carbohydrate intake (as a percentage of energy) of the highest quintiles of TLCD score at baseline ranged from 38.3% in HPFS to 40.9% in NHSII. Mean weight gain over 4-year intervals among participants varied from 0.8 kg in the HPFS to 1.8 kg in the NHSII. After adjusting for demographics and baseline and concomitant changes of selected lifestyle factors, each 1-SD increase in TLCD score was associated with 0.06 (95% CI, 0.04-0.08) kg more weight gain over the 4-year periods. Similarly, participants gained 0.13 (95% CI, 0.11 to 0.14) kg per each 1-SD increase in ALCD score and 0.39 (95% CI, 0.37 to 0.40) kg per each 1-SD change in ULCD score. In contrast, each 1-SD increase in VLCD score was associated with 0.03 (95% CI, 0.01 to 0.04) kg less weight gain, and each 1-SD increase in HLCD score was associated with 0.36 (95% CI, 0.35 to 0.38) kg less weight gain. The associations were more pronounced among obese individuals (per 1-SD increase in HLCD score: BMI ≥30, 0.88 [95% CI, 0.80, 0.97] kg less weight gain; BMI <25, 0.23 [95% CI, 0.20, 0.26] kg less weight gain; P for interaction < .001).

Conclusions and Relevance

These findings suggest that the quality of LCDs may play a critical role in modulating long-term weight change. Only LCDs that emphasized high-quality protein, fat, and carbohydrates from whole grains and other plant-based foods were associated with less weight gain.

Plant-based dietary patterns and fasting insulin: a cross-sectional study from NHANES 2017-2018

BACKGROUND

Previous studies have created plant-based diet indices to assess the health effects of specific dietary patterns.

OBJECTIVE

To examine the association between the plant-based content of diet and fasting insulin in adults from the NHANES 2017-2018 database.

METHODS

Demographic, dietary, lab and clinical data and fasting insulin were obtained from the NHANES 2017-2018 database. From two 24-h dietary recalls, we created a plant-based diet index (PDI) and a healthy plant-based diet index (hPDI). A high PDI score indicated more plants were consumed versus animal foods. A high hPDI score indicated healthier, plant materials (whole grains, whole fruits, vegetables, legumes, vegetable oils, seeds and nuts) were consumed. The relationships between the natural log of fasting insulin, PDI, and hPDI were analyzed using multiple linear regression adjusting for body mass index (BMI) and alanine aminotransferase (ALT).

RESULTS

Analyses were based on 1,714 participants, 897 women and 817 men with a median age of 52 years. In this sample, 610 (35.6%) were white, 407 (23.8%) were black, 231 (13.5%) were Mexican, 207 (12.1%) were Asian, 157 (9.2%) were other Hispanic, and 102 (6%) were other or mixed race. Median fasting insulin was 9.74 μU/mL (IQR: 6.2, 15.56). For every 1 unit increase in PDI, the natural log of fasting insulin decreased 0.0068 ± 0.003 μU/mL (CI: -0.00097, -0.013) (p = 0.02). After adjusting for BMI and ALT, the PDI did not significantly predict fasting insulin as the association was not robust due to multicollinearity. The hPDI was inversely and significantly associated with the natural log of fasting insulin (-0.0027 ± 0.00134, CI: -0.000087, -0.0053) (p = 0.043) in a multivariable model including BMI and ALT.

CONCLUSION

A healthy plant-based diet is associated with a decrease in fasting insulin levels. Healthfulness of the diet is an important factor when considering the benefit of a plant-based diet.

Plant protein consumption is associated with body mass index among women of reproductive age in Indonesia

Introduction

One of the known determinants of obesity in Southeast Asia countries, including Indonesia, is the nutritional transition, which is indicated by fast changes in food production, dietary habits, and physical activity. With rising incomes, plant protein from grains, tubers, and legumes is gradually being replaced by animal protein from poultry, eggs, dairy, and red meat. This change is identified as a protein transition. Different choices of protein sources in the diet have varying health effects. However, there is limited information on the Asian population on the role of protein consumption on the increasing obesity prevalence. Therefore, this study aimed to investigate the association of protein sources consumption with body mass index (BMI) among women of reproductive age in Indonesia.

Methods

This study used secondary data from the 2018 Indonesia Food Barometer (IFB) conducted using a quantitative cross-sectional survey. A total of 467 Indonesian reproductive-aged women (20-49 years) were included in this study. Dietary intake, including protein consumption, was obtained using 24-h dietary recall. Multiple linear regression was applied to find the association of protein consumption with BMI with a p-value <0.05 considered as a significant outcome variable.

Results

The Mean BMI was 25.02 kg/m2, median of animal and plant protein was 28.01 g/day and 25.37 g/day, respectively. Consumption of plant protein was significantly associated with BMI after adjusting for marital status and age (p-value = 0.043; R2 = 0.080). The quality of plant protein should be considered to prevent obesity problems among women of reproductive age.

The effects of plant-based dietary patterns on the risk of developing gestational diabetes mellitus: A systematic review and meta-analysis

BACKGROUND

The worldwide prevention of gestational diabetes mellitus (GDM) is a significant health challenge. Plant-based dietary patterns are a series dietary habits that emphasized foods derived from plant sources more and from animal foods less. Now, no consensus exists on the effects of plant-based dietary patterns on the incident of GDM.

OBJECTIVE

This study aimed to estimate the effects of plant-based dietary patterns on the risk of developing GDM.

METHODS

This systematic review was conducted following the checklist of PRISMA. Six electronic databases including PubMed, Embase, Web of Science, China National Knowledge Infrastructure, Wangfang, and Chinese Scientific Journals Database were searched from inception to November 20, 2022. A fixed or random effect model was used to synthesize results of included studies. Then, subgroup analysis, meta-regression and sensitivity analysis were performed to assure the reliability and stability of the results.

RESULTS

Ten studies including 32,006 participants were identified. The results of this study showed that the better adherence to the plant-based dietary patterns was related to the lower risk of developing GDM (RR = 0.88[0.81 to 0.96], I2 = 14.8%). The slightly stronger association between plant-based diets and the risk of developing GDM was found when healthy plant-based dietary pattern index was included in pooled estimate (RR = 0.86[0.79 to 0.94], I2 = 8.3%), compared with that unhealthy one was included (RR = 0.90[0.82 to 0.98], I2 = 8.3%).

CONCLUSION

The plant-based dietary patterns are associated with a lower risk of developing GDM. Furthermore, healthy plant-based dietary patterns are more recommended than unhealthy one. It is significant to help medical staff to guide pregnant women to choose reasonable diets.

An Unhealthy Plant-Based Diet Increases Risk of Hypertension but not Framingham Risk Score in Adults

Backgrounds

We investigated the relation of plant-based diets (PDs) with hypertension (HTN) and Framingham risk score (FRS) in Iranian adults.

Objectives

We hypothesized that healthy PDs might have positive effects on blood pressure (BP) and FRS, whereas less-healthy plant-based foods might have negative effects.

Methods

The current cross-sectional study was performed on 527 middle-aged adults (45.7% women), who were selected through a multistage cluster random-sampling method. The assessment of dietary intakes was performed by using a validated food-frequency questionnaire. Twelve-hour fasting blood samples were collected to evaluate total cholesterol and high-density lipoprotein concentrations. BP was measured through the standard method and HTN was defined as BP ≥130/80 mmHg. FRS was used to predict the 10-y risk for development of cardiovascular disease (CVD).

Results

The prevalence of HTN and high FRS among study participants were, respectively, 62% and 15.6%. After adjustment for potential confounders, plant-based diet index (PDI) and healthy plant-based diet index (hPDI) were not significantly associated with HTN [odds ratio (OR): 0.99; 95% confidence interval (CI): 0.55, 1.79 and OR: 0.83; 95% CI: 0.45, 1.53, respectively)]. However, those in the highest tertile of unhealthy plant-based diet index (uPDI) in comparison with those in the bottom tertile had a 100% increased odds of HTN (OR: 2.00; 95% CI: 1.04, 3.88). Greater adherence to PDI, hPDI, and uPDI was not related to high FRS chance, in fully adjusted model (OR: 0.50; 95% CI: 0.15, 1.65; OR: 1.03; 95% CI: 0.26, 4.04; and OR: 2.05; 95% CI: 0.56, 7.52, respectively).

Conclusions

This study demonstrated that less-healthy PDs would enhance the chance of HTN in Iranian adults, although PDIs were not significantly related to the 10-y risk of developing CVD.

Association between changes in carbohydrate intake and long term weight changes: prospective cohort study

OBJECTIVE

To comprehensively examine the associations between changes in carbohydrate intake and weight change at four year intervals.

DESIGN

Prospective cohort study.

SETTING

Nurses' Health Study (1986-2010), Nurses' Health Study II (1991-2015), and Health Professionals Follow-Up Study (1986-2014).

PARTICIPANTS

136 432 men and women aged 65 years or younger and free of diabetes, cancer, cardiovascular disease, respiratory disease, neurodegenerative disorders, gastric conditions, chronic kidney disease, and systemic lupus erythematosus before baseline.

MAIN OUTCOME MEASURE

Weight change within a four year period.

RESULTS

The final analyses included 46 722 women in the Nurses' Health Study, 67 186 women in the Nurses' Health Study II, and 22 524 men in the Health Professionals Follow-up Study. On average, participants gained 1.5 kg (5th to 95th centile -6.8 to 10.0) every four years, amounting to 8.8 kg on average over 24 years. Among men and women, increases in glycemic index and glycemic load were positively associated with weight gain. For example, a 100 g/day increase in starch or added sugar was associated with 1.5 kg and 0.9 kg greater weight gain over four years, respectively, whereas a 10 g/day increase in fiber was associated with 0.8 kg less weight gain. Increased carbohydrate intake from whole grains (0.4 kg less weight gain per 100 g/day increase), fruit (1.6 kg less weight gain per 100 g/day increase), and non-starchy vegetables (3.0 kg less weight gain per 100 g/day increase) was inversely associated with weight gain, whereas increased intake from refined grains (0.8 kg more weight gain per 100 g/day increase) and starchy vegetables (peas, corn, and potatoes) (2.6 kg more weight gain per 100 g/day increase) was positively associated with weight gain. In substitution analyses, replacing refined grains, starchy vegetables, and sugar sweetened beverages with equal servings of whole grains, fruit, and non-starchy vegetables was associated with less weight gain. The magnitude of these associations was stronger among participants with overweight or obesity compared with those with normal weight (P<0.001 for interaction). Most of these associations were also stronger among women.

CONCLUSIONS

The findings of this study highlight the potential importance of carbohydrate quality and source for long term weight management, especially for people with excessive body weight. Limiting added sugar, sugar sweetened beverages, refined grains, and starchy vegetables in favor of whole grains, fruit, and non-starchy vegetables may support efforts to control weight.

Scoping review of the association of plant-based diet quality with health outcomes

Introduction

The association of plant-based dietary patterns with health outcomes has traditionally been assessed without considering nutritional value. The plant-based dietary index (PDI), first published in 2016, overcomes this limitation with both a healthful PDI (hPDI) and an unhealthful PDI (uPDI), based on the quality of plant foods consumed plus the frequency of animal foods. We sought to summarize the breadth of research using the hPDI and uPDI to gain insight into how the quality of plant-based dietary patterns might be associated with health outcomes.

Methods

Scoping review of studies that used the PDI, hPDI, or uPDI to report associations with health outcomes. Multiple databases were searched from 2010 through April 2023 with 2 authors independently assessing eligibility and extracting data. In addition to assessing the association of the indices to health outcomes, we determined the frequency of concordant or discordant findings for hPDI versus PDI and for hPDI versus uPDI.

Results

We included 95 articles (54% longitudinal, 37% cross-sectional, and 9% case-control) with a median sample size of 3,646. Higher hPDI levels were associated with favorable health outcomes in 36% of comparisons (most often for obesity, mortality, diabetes, cardiovascular disease, and psychiatric disorders), compared to 25% for the PDI and only 2% for the uPDI. Conversely, higher levels of the uPDI were associated with unfavorable health outcomes in 33% of comparisons, in contrast to under 1% for the hPDI and 2% for the PDI. When the hPDI association to an outcome was discordant with the uPDI or PDI, the significance and directionality always favored the hPDI over the uPDI, and nearly always favored the hPDI over the PDI.

Discussion

Dietary indices that account for the quality of plant foods can show health benefits that might be missed by a generic plant-based index. A greater focus on the quality of plant foods could improve nutrition guidelines, raise awareness about the benefits of adding unrefined plant foods to the diet, and empower consumers to make incremental additions of such foods to displace unhealthy foods. We anticipate increasing use of indices that address food quality in future research.

Position statement on nutrition therapy for overweight and obesity: nutrition department of the Brazilian association for the study of obesity and metabolic syndrome (ABESO-2022)

Obesity is a chronic disease resulting from multifactorial causes mainly related to lifestyle (sedentary lifestyle, inadequate eating habits) and to other conditions such as genetic, hereditary, psychological, cultural, and ethnic factors. The weight loss process is slow and complex, and involves lifestyle changes with an emphasis on nutritional therapy, physical activity practice, psychological interventions, and pharmacological or surgical treatment. Because the management of obesity is a long-term process, it is essential that the nutritional treatment contributes to the maintenance of the individual's global health. The main diet-related causes associated with excess weight are the high consumption of ultraprocessed foods, which are high in fats, sugars, and have high energy density; increased portion sizes; and low intake of fruits, vegetables, and grains. In addition, some situations negatively interfere with the weight loss process, such as fad diets that involve the belief in superfoods, the use of teas and phytotherapics, or even the avoidance of certain food groups, as has currently been the case for foods that are sources of carbohydrates. Individuals with obesity are often exposed to fad diets and, on a recurring basis, adhere to proposals with promises of quick solutions, which are not supported by the scientific literature. The adoption of a dietary pattern combining foods such as grains, lean meats, low-fat dairy, fruits, and vegetables, associated with an energy deficit, is the nutritional treatment recommended by the main international guidelines. Moreover, an emphasis on behavioral aspects including motivational interviewing and the encouragement for the individual to develop skills will contribute to achieve and maintain a healthy weight. Therefore, this Position Statement was prepared based on the analysis of the main randomized controlled studies and meta-analyses that tested different nutrition interventions for weight loss. Topics in the frontier of knowledge such as gut microbiota, inflammation, and nutritional genomics, as well as the processes involved in weight regain, were included in this document. This Position Statement was prepared by the Nutrition Department of the Brazilian Association for the Study of Obesity and Metabolic Syndrome (ABESO), with the collaboration of dietitians from research and clinical fields with an emphasis on strategies for weight loss.

The association of plant-based dietary pattern with general and abdominal obesity: a large cross-sectional study

Purpose

Only a few studies have studied the association between plant-based dietary index (PDI) and the prevalence of obesity. The purpose of this study was to investigate the association between PDI and the prevalence of general and abdominal obesity in a large sample of Iranian adults.

Methods

The current cross-sectional study was performed from 2010 to 2012 in Isfahan, Iran. This study comprised 6,724 adults between the ages of 18 and 55. We analyzed data from 6,724 participants who were classified as having general obesity and 5,203 individuals who were classified as having abdominal obesity. Dietary intake was assessed using a validated food frequency questionnaire. We determined the PDI by assigning plant foods positive scores and animal foods negative values using the method of Satija et al. General obesity was defined as having a body mass index (BMI) greater than 30 kg/m2, whereas abdominal obesity was classified as having a waist circumference (WC) greater than 88 cm for women and 102 cm for men. Data was examined using Chi-squared test and the analysis of variance (ANOVA and ANCOVA). Multivariable binary logistic regression analyses were performed to evaluate the association between PDI and risk of general as well as abdominal obesity.

Results

The mean age of the study participants was 36.8 ± 8.08 years, and 57% of them were female. General obesity prevalence was 9.6%, while abdominal obesity was 26.8%. In all the unadjusted and multivariable adjusted models of the total population, there was no significant association between highest vs. lowest adherence to the PDI and general obesity or abdominal obesity. No significant association was found when men and women were analyzed separately as well.

Conclusion

In the present study, no association was observed between PDI and general and abdominal obesity in the Iranian adult population.

The relationship between a plant-based diet and mental health: Evidence from a cross-sectional multicentric community trial (LIPOKAP study)

BACKGROUND

Dietary patterns emphasizing plant foods might be neuroprotective and exert health benefits on mental health. However, there is a paucity of evidence on the association between a plant-based dietary index and mental health measures.

OBJECTIVE

This study sought to examine the association between plant-based dietary indices, depression and anxiety in a large multicentric sample of Iranian adults.

METHODS

This cross-sectional study was performed in a sample of 2,033 participants. A validated food frequency questionnaire was used to evaluate dietary intakes of participants. Three versions of PDI including an overall PDI, a healthy PDI (hPDI), and an unhealthy PDI (uPDI) were created. The presence of anxiety and depression was examined via a validated Iranian version of the Hospital Anxiety and Depression Scale (HADS).

RESULTS

PDI and hPDI were not associated to depression and anxiety after adjustment for potential covariates (age, sex, energy, marital status, physical activity level and smoking). However, in the crude model, the highest consumption of uPDI approximately doubled the risk of depression (OR= 2.07, 95% CI: 1.49, 2.87; P<0.0001) and increased the risk of anxiety by almost 50% (OR= 1.56, 95% CI: 1.14, 2.14; P= 0.001). Adjustment for potential confounders just slightly changed the associations (OR for depression in the fourth quartile= 1.96; 95% CI: 1.34, 2.85, and OR for anxiety in the fourth quartile= 1.53; 95% CI: 1.07, 2.19).

CONCLUSIONS

An unhealthy plant-based dietary index is associated with a higher risk of depression and anxiety, while plant-based dietary index and healthy plant-based dietary index were not associated to depression and anxiety.

Association between plant-based diets and metabolic syndrome in obese adults from Iran: a cross-sectional study

BACKGROUND

Metabolic syndrome (MetS) is a common chronic disease with several complications. Given that, studies on the association of plant-based diet indices (PDIs) with risk of MetS among adults with obesity, are limited, we aimed to examine the association between PDIs (including overall PDI, healthy PDI (hPDI), unhealthy PDI (uPDI)) and MetS in Iranian adults with obesity.

METHODS

In Tabriz, Iran, a total of 347 adults between the ages of 20 and 50 participated in this cross-sectional research study. We created an overall PDI, hPDI, and uPDI from validated semi-quantitative food-frequency questionnaire (FFQ) data. To investigate the association between hPDI, overall PDI, uPDI, and MetS and its components, a binary logistic regression analysis was performed.

RESULTS

The average age was 40.78 ± 9.23 years, and the average body mass index was 32.62 ± 4.80 kg/m². There was no significant association between overall PDI (OR: 0.87; 95% CI: 0.54-1.47), hPDI (OR: 0.82; 95% CI: 0.48-1.40), and uPDI (OR: 0.83; 95% CI: 0.87-2.46) with MetS, even after adjustment for confounders. Moreover, our findings showed that participants with the highest adherence to uPDI had a higher chance of hyperglycemia (OR: 2.50; 95% CI: 1.13-5.52). Also, this association was significant in the first (OR: 2.51; 95% CI: 1.04-6.04) and second (OR: 2.58; 95% CI: 1.05-6.33) models, after controlling for covariates. However, in both adjusted and crude models, we did not find a significant association between hPDI and PDI scores and MetS components such as high triglyceride, high waist circumference, low High-density lipoprotein cholesterol, raised blood pressure, and hyperglycemia. Moreover, those in the top tertile of uPDI had higher fasting blood sugar and insulin levels when compared with those in the first tertile, and subjects in the last tertile of hPDI compared with participants in the first tertile had lower weight, waist-to-hip ratio, and fat-free mass.

CONCLUSION

We found a direct significant association between uPDI and odds of hyperglycemia in the whole population of study. Future large-scale, prospective studies on PDIs and the MetS are necessary to confirm these findings.

Association of plant-based dietary patterns with metabolic syndrome: baseline results from the Persian Kavar cohort study (PKCS)

Plant-based diets (PBDs) have gained a positive reputation among experts as a solution to combat the epidemic of MetS. A total of 2225 healthy Iranian individuals aged 35-70 years were considered eligible to be included in this cross-sectional investigation. Various dietary, anthropometric, and biochemical assessments were conducted using standard, valid methods/tools. Relevant PBD scores were calculated using three a posteriori indices, including the overall plant-based diet index (PDI), healthful PDI (hPDI), and unhealthful PDI (uPDI). Our findings showed that women with the highest adherence to hPDI had a lower chance of MetS. Also, participants in the top tertiles of hPDI were more likely to have a lower risk of low serum HDL-c and abnormal glucose homeostasis. Additionally, a significant increasing trend was observed for low serum HDL-c across tertiles of uPDI. Our observations suggest that healthful-rich plant foods may have a protective effect against MetS, especially in women.

Weight-Control Behaviors and Dietary Intake in Chinese Adults: An Analysis of Three National Surveys (2002–2015)

Weight control through dietary management is becoming increasingly common worldwide. This study aimed to evaluate and compare the dietary intake and diet quality between Chinese adults with and without weight-control behaviors. Data were collected from the China National Nutrition Survey 2002, 2012, and 2015. Dietary intake was assessed using a combination of 24 h dietary recall of three consecutive days and a weighing method. Diet quality was calculated based on China healthy diet index (CHDI). A total of 167,355 subjects were included, of which 11,906 (8.0%) adults reported attempting to control weight within the past 12 months. Participants with weight control had lower daily total energy intake, as well as lower percentages of energy from carbohydrates, low-quality carbohydrates, and plant protein, but higher percentages of energy from protein, fat, high-quality carbohydrates, animal protein, saturated fatty acids, and monounsaturated fatty acids than those without weight control. Additionally, the CHDI score in the weight-control group was higher than those without (53.40 vs. 48.79, p < 0.001). Fewer than 40% of participants in both groups met the requirement for all specific food groups. Chinese adults who reported weight-control behaviors had an energy-restricted diet characterized by reduced carbohydrate intake and overall higher diet quality compared with those without dietary-control behaviors. However, both groups had significant room for improvement in meeting dietary recommendations.

Higher Adherence to Plant-Based Diet Lowers Type 2 Diabetes Risk among High and Non-High Cardiovascular Risk Populations: A Cross-Sectional Study in Shanxi, China

This study aimed to investigate the association between the plant-based diet index (PDI) score and T2D risk among residents of Shanxi Province, China, and explore whether the association was influenced by different levels of cardiovascular risk. A total of 50,694 participants aged 35-75 years were recruited between 2017 and 2019, and they were further divided into the high cardiovascular risk population (HCRP; n = 17,255) and the non-high cardiovascular risk population (non-HCRP; n = 33,439). The PDI was calculated based on food frequency from a food frequency questionnaire (FFQ). Incident T2D was defined based on elevated plasma glucose (≥7 mmol/L) or hypoglycemic medicine use. We investigated the association of the PDI andT2D risk using a two-level generalized estimating equation and restricted cubic splines model. The results showed that quartile 4 of the PDI indicated significantly reduced T2D risk in the total population (OR: 0.83; 95% CI: 0.75-0.92), HCRP (OR: 0.80; 95% CI: 0.71-0.91), and non-HCRP (OR: 0.80; 95% CI: 0.74-0.87) compared with corresponding quartile 1 (OR = 1). In stratified analysis, the negative associations between PDI and T2D risk were stronger in the total population with the elderly (age > 60 years), BMI < 24, and men, and in the non-HCRP with men and BMI 24-28, and in the HCRP with the elderly and BMI < 24 than those with corresponding subgroups (pinteraction < 0.05). Linear curves were observed for the total population and non-HCRP, but an L-shaped association was observed for the HCRP. Therefore, our results suggest that higher PDI scores may effectively attenuate the T2D risk in the Chinese population and non-HCRP, and a beneficial association of PDI with T2D risk was observed in the HCRP at a certain threshold level. Longitudinal studies and intervention trials are required to validate our study findings.

Association between Different Types of Plant-Based Diets and Dyslipidemia in Middle-Aged and Elderly Chinese Participants

Plant-based dietary patterns may reduce the risk of dyslipidemia. However, not all plant-based foods are beneficial, and limited data exist for the Chinese population. We investigated the association between different plant-based dietary indices and the risk of dyslipidemia in a Chinese middle-aged and elderly population. The study participants (n = 4096) consisted of adults between 35 and 74 years of age from Xinjiang, China. Dietary consumption of the study participants was evaluated using a semi-quantitative food-frequency questionnaire (FFQ). Three different plant-based dietary indices were calculated using data from dietary surveys, including overall plant-based diet index (PDI), healthy plant-based diet index (hPDI), and unhealthy plant-based diet index (uPDI). Based on these indices, we created an adjusted plant-based diet index (aPDI) based on the Xinjiang population actual dietary behavior and health effects of food. We measured the levels of total cholesterol, triglyceride, LDL-C, and HDL-C in the blood of the study participants. We used multivariable logistic regression and restricted cubic spline to analyze the relationship between plant-based diets and dyslipidemia. The findings showed that 36.6% of the participants had dyslipidemia. Higher PDI adherence was related to lower odds of dyslipidemia (Q3 vs. Q1, OR: 0.780, 95% CI: 0.641-0.949; Q4 vs. Q1, OR: 0.799, 95% CI: 0.659-0.970). High aPDI was related to lower odds of dyslipidemia (Q4 vs. Q1, OR: 0.770, 95% CI: 0.628-0.945; Q5 vs. Q1, OR: 0.748, 95% CI: 0.607-0.921). High scores for PDI, hPDI, and aPDI were all related to a reduced risk of low HDL-C (OR: 0.638, 95% CI: 0.491-0.823; OR: 0.661, 95% CI: 0.502-0.870; OR: 0.580, 95% CI: 0.443-0.758). Conversely, a high uPDI score was associated with an increased risk of low HDL-C (OR: 1.349, 95% CI: 1.046-1.740). There was no non-linear relationship between PDI, hPDI, uPDI, and aPDI and the risk of different types of dyslipidemia. Plant-based dietary indices are related to specific types of dyslipidemia risk. Appropriately increasing the consumption of plant-based foods while improving the quality of plant-based dietary patterns is critical for the prevention of dyslipidemia, especially low HDL-C, in the population.

Association of plant-based diets with adropin, atherogenic index of plasma, and metabolic syndrome and its components: A cross-sectional study on adults

Background

Little is known about the association of plant-based diet indices with metabolic syndrome (MetS) and its novel predictive biomarkers, including the atherogenic index of plasma (AIP) and adropin. We aimed to investigate the association of plant-based diets with adropin, atherogenic index of plasma, and MetS and its components in adults.

Methods

The present population-based cross-sectional study was conducted on a representative sample of adults aged 20-60 years in Isfahan, Iran. Dietary intake was obtained through a validated 168-item semi-quantitative food frequency questionnaire (FFQ). Peripheral blood was obtained after an overnight fast of at least 12 h from each participant. MetS was identified based on the Joint Interim Statement (JIS). AIP was calculated as a logarithmically transformed ratio of triglyceride (TG)/high-density lipoprotein cholesterol (HDL-c), and serum levels of adropin were measured by an ELISA kit.

Results

A total of 28.7% of subjects had MetS. No significant association was found between the overall plant-based diet index (PDI) and the healthful plant-based diet index (hPDI) with MetS. However, a non-linear association was observed between hPDI and MetS. Subjects in the third quartile of the unhealthful plant-based diet index (uPDI) had higher odds of MetS compared to the first quartile (OR: 2.39; 95% CI: 1.01, 5.66). The highest quartile of PDI (OR: 0.46; 95% CI: 0.21, 0.97) and the third quartile of hPDI (OR: 0.40; 95% CI: 0.18, 0.89) were associated with decreased odds of having high-risk AIP compared to the first quartile, after adjusting for potential confounders. No linear association was found between quartiles of plant-based diet indices and serum levels of adropin.

Conclusion

Plant-based diet index (PDI) and hPDI were not associated with the prevalence of MetS in adults, while moderate adherence to uPDI increased the prevalence of MetS. In addition, high adherence to PDI and moderate adherence to hPDI were associated with decreased odds of high-risk AIP. No significant association was found between plant-based diet indices and serum adropin levels. To confirm these findings, further studies with prospective designs are warranted.

Association between the quality of plant-based diets and risk of frailty

BACKGROUND

The Mediterranean diet and other dietary patterns rich in fruits and vegetables have been linked to lower risk of frailty in older adults. However, not all plant-based diets are necessarily healthful, and no previous study has evaluated the role of the quality of plant-based dietary patterns in frailty risk. Our aim was to assess the association between plant-based diet quality and risk of frailty.

METHODS

Prospective cohort consisted with 82 234 women aged ≥60 years from the Nurses' Health Study, who were followed from 1990 through 2014. The dates of analysis were April 14 to June 23, 2021. Dietary data were collected every 4 years using a validated semi-quantitative food frequency questionnaire. The plant-based diet quality was assessed with two indices (range 18-90 points): (a) healthful plant-based diet index (hPDI), where healthy plant foods (whole grains, fruits, vegetables, nuts, legumes, vegetable oils and tea/coffee) received positive scores, while less healthy plant foods (fruit juices, sweetened beverages, refined grains, potatoes, and sweets/desserts) and animal foods received reverse scores; and (b) unhealthful plant-based diet index (uPDI) where positive scores were given to less healthy plant foods and reverse scores to healthy plant foods and animal foods. Frailty incidence was assessed every 4 years, being defined as having three or more of the following five criteria from the FRAIL scale: fatigue, low strength, reduced aerobic capacity, having ≥5 illnesses and weight loss ≥5%. Multivariable-adjusted Cox proportional-hazards models were used to estimate hazard ratios (HRs) and their 95% confidence interval (CI).

RESULTS

We identified 12 910 incident cases of frailty over 1 176 401 person-year follow-up. In the multivariable analysis, the hPDI was inversely associated with the risk of frailty (hazard ratio [HR] for the highest vs. lowest quintile: 0.77, 95% confidence interval: 0.72-0.81; P trend <0.001). In addition, a 10-unit increment in the hPDI was associated with a relative 15% lower risk of frailty. Conversely, a direct association was found between the uPDI and risk of frailty (HR highest vs. lowest quintile: 1.24 [1.17, 1.32], P trend <0.001). These associations were consistent for each frailty criterion, among participants with no frailty criteria at baseline, after excluding participants with diabetes, cancer and cardiovascular disease at baseline, for alternative versions of the plant-based diet indices (PDIs), in subgroup analysis by categories of potential confounders, and in latency analysis.

CONCLUSIONS

A healthful plant-based diet was associated with lower risk of frailty whereas an unhealthful plant-based diet was associated with higher risk.

Joint Associations of Food Groups with All-Cause and Cause-Specific Mortality in the Mr. OS and Ms. OS Study: A Prospective Cohort

Despite continuous growth in dietary pattern research, the relative importance of each dietary component in the overall pattern and their joint effects on mortality risk have not been examined adequately. We explored the individual and joint associations of multiple food groups with all-cause and cause-specific mortality (cardiovascular disease (CVD) or cancer), by analyzing data from a cohort of 3995 Hong Kong Chinese older adults in the Mr. Osteoporosis (OS) and Ms. OS Study. Cox proportional hazards models were used to examine the associations of food groups with mortality risk. The individual and joint contribution of food groups to mortality risk has been quantified by a machine learning approach, i.e., the Quantile G-Computation. When comparing the highest with the lowest quartile of intake, dark green and leafy vegetables (hazard ratio (HR) = 0.82, 95% confidence interval (CI) = 0.70 to 0.96, Ptrend = 0.049), fruit (HR = 0.79, 95% CI = 0.68 to 0.93, Ptrend = 0.006), legumes (HR = 0.75, 95% CI = 0.63 to 0.87, Ptrend = 0.052), mushroom and fungi (HR = 0.76, 95% CI = 0.65 to 0.88, Ptrend = 0.023), soy and soy products (HR = 0.77, 95% CI = 0.66 to 0.90, Ptrend = 0.143), and whole grains (HR = 0.76, 95% CI = 0.65 to 0.89, Ptrend = 0.008) were inversely associated with all-cause mortality. Legume intake was associated with a lower risk of CVD mortality, while fruit, nuts, soy and soy products were associated with a lower risk of cancer mortality. From the Quantile G-Computation, whole grains, legumes, fruits, mushroom and fungi, soy and soy products had a higher relative weighting on mortality risk, and the joint effect of food groups was inversely associated with the mortality risk due to all-causes (HR = 0.39, 95% CI = 0.27 to 0.55), CVD (HR = 0.78, 95% CI = 0.67 to 0.91), and cancer (HR = 0.31, 95% CI = 0.15 to 0.65). From a sex-stratified analysis, most associations between food groups (whole grains, legumes, fruits, mushroom and fungi, soy and soy products) and mortality risk remained significant among men. In conclusion, whole grains, legumes, fruits, mushroom and fungi, soy and soy products were the main contributors to a reduction in mortality risk, and their joint effects were stronger than individual food groups. Moreover, the sex-specific association of sweets and desserts with cancer mortality may be worth further investigation.

Association between different types of plant-based diet and dyslipidaemia in Korean adults

This study investigated the association between the different types of plant-based diets and dyslipidaemia in Korean adults using data from the nationally representative sample. Using the 2012–2016 Korea National Health and Nutrition Survey data, a total of 14 167 adults (≥19 years old) participated in this study. Dietary intake was assessed by a semi-quantitative FFQ. Three different plant-based diet indices (overall plant-based diet index (PDI), healthful plant-based diet index (hPDI), unhealthful plant-based diet index (uPDI)), were calculated. Dyslipidaemia and its components (hypertriacylglycerolaemia, hypercholesterolaemia, low HDL-cholesterol, high LDL-cholesterol, use of anti-hyperlipidaemia agent) were measured. Multivariable logistic regression analysis was used to examine the associations between plant-based diet and dyslipidaemia and individual lipid disorders. Totally, 47% of overall population had dyslipidaemia. Individual in the highest quintile of uPDI had 22% greater odds of dyslipidaemia (95 % CI 1·05, 1·41) and 48 % higher odds of hypertriacylglycerolaemia (95 % CI 1·21, 1·81) and 16% higher odds of low HDL-cholesterol (OR: 1·16, 95 % CI 1·00, 1·35) than those in the lowest quintile of uPDI. PDI was associated with 16 % higher odds of low HDL-cholesterol, and hPDI was associated with 25% lower odds of high LDL-cholesterol. However, neither PDI nor hPDI was significantly associated with the prevalence of dyslipidaemia. Greater adherence to unhealthful plant-based diets was associated with greater odds of the dyslipidaemia and its components suggesting the importance of the quality of plant-based diet in South Korean adults for dyslipidaemia prevention.

Association between plant-based diets and metabolic health status in adolescents with overweight and obesity

The association of plant-based diets with health status is underestimated in pediatrics. We aimed to examine the relation between plant-based diets (including overall plant-based index (PDI), healthy plant-based (hPDI) and unhealthy plant-based (uPDI)) and metabolic health status in Iranian adolescents with overweight/obesity. We conducted a cross-sectional study on 203 adolescents with overweight/obesity (12-18 years old) selected by a multistage cluster random-sampling method. Usual dietary intakes were assessed through a validated 147-item food frequency questionnaire (FFQ). Anthropometric indices and blood pressure values were measured and fasting blood samples were drawn. For classification of participants into metabolically healthy obese (MHO) or metabolically unhealthy obese (MUO) groups, two methods of International Diabetes Federation (IDF) and combination of IDF with Homeostasis Model Assessment Insulin Resistance (HOMA-IR) were applied. No significant association was observed between higher adherence to PDI and odds of MUO status defined by both IDF and IDF/HOMA-IR strategies. After adjustments for all potential confounders, adolescents in the highest tertile of hPDI, compared with those in the lowest tertile, had 85% (95% CI 0.05-0.43) and 84% (95% CI 0.05, 0.52) lower odds of being MUO based on IDF and IDF/HOMA-IR criteria, respectively. Greater adherence to uPDI was associated with odd of 3.95 (95% CI 1.41, 11.12) and 4.06 (95% CI 1.31, 12.57) of being MUO based on IDF and IDF/HOMA-IR definitions, after considering all potential confounders. Stratified analysis revealed that these associations were stronger in girls and overweight subjects. Adherence to healthy plant-based foods was inversely associated with odds of MUO status in Iranian adolescents. In contrast, unhealthy plant-based diets was directly associated with MUO in pediatrics. Further studies with prospective nature, are required to affirm these results.

Positive association of unhealthy plant-based diets with the incidence of abdominal obesity in Korea: a comparison of baseline, most recent, and cumulative average diets

OBJECTIVES

Different approaches for analyzing repeated dietary measurements may yield differences in the magnitude and interpretation of findings. We aimed to compare 3 dietary measurements (baseline, most recent, and cumulative average) in terms of the association between plant-based diet indices (PDIs) and incident abdominal obesity in Korean adults aged 40-69 years.

METHODS

This study included 6,054 participants (54% women) free of abdominal obesity (defined as waist circumference ≥90 cm for men and ≥85 cm for women) at baseline. As exposures, baseline, most recent, and cumulative average measurements for PDI, healthy-PDI (hPDI), and unhealthy-PDI (uPDI) were created. A Cox proportional-hazard model was used to estimate the hazard ratios (HRs) for abdominal obesity.

RESULTS

During 45,818 person-years of follow-up (median, 9 years), we identified 1,778 incident cases of abdominal obesity. In the multivariable-adjusted analysis, a higher uPDI was associated with a higher risk of abdominal obesity in both total and stratified analyses. The findings were consistent across all approaches (Q5 vs. Q1: HRbaseline=1.70; 95% confidence interval [CI], 1.46 to 1.98; HRmost recent=1.52; 95% CI, 1.30 to 1.78; HRcumulative average=1.76; 95% CI, 1.51 to 2.06 in the total set). PDI showed no meaningful association with abdominal obesity risk in any analyses. hPDIaverage had a suggestive inverse association with abdominal obesity risk in men, and hPDIbaseline had a positive association with abdominal obesity risk in women.

CONCLUSIONS

Greater adherence to unhealthy plant-based diets may increase the risk of developing abdominal obesity in Korean adults. The findings were generally consistent across all approaches.

A healthy plant-based diet was associated with slower cognitive decline in African American older adults: a biracial community-based cohort

BACKGROUND

African American (AA) adults have about twice the risk of developing dementia compared with white adults. However, evidence on dietary modification in preventing cognitive decline from diverse populations focusing on AA adults is minimal.

OBJECTIVES

We aimed to evaluate the association between a plant-based diet and the rate of cognitive decline in a population-based sample of AA and white adults.

METHODS

This study consisted of 3337 participants from the Chicago Health and Aging Project (60% AA participants, 64% female). Plant-based diet quality was evaluated by the overall plant-based diet index (PDI), the healthful PDI (hPDI), and the unhealthful PDI (uPDI). Global cognition was assessed using a composite score of 4 individual tests of cognition. We used mixed models to examine the associations of PDI, hPDI, and uPDI with the rates of decline in global cognition, perceptual speed, and episodic memory. Models were adjusted for age, sex, presence of apoE e4 allele, lifestyle factors including education, cognitive activities, smoking status, calorie intake, risk factors for cardiovascular disease, time, and the interaction terms of time × each covariate.

RESULTS

AA and white participants had various dietary patterns. Higher hPDI was associated with a slower rate of decline in global cognition, perceptual speed, and episodic memory in AA participants but not white participants. AA study participants in the highest quintile of hPDI had significantly slower rates of global cognitive decline (β: 0.0183 ± 0.0086; P = 0.032), perceptual speed (β: 0.0179 ± 0.0088; P = 0.04), and episodic memory (β: 0.0163 ± 0.0118; P = 0.04) than individuals in the lowest quintile of hPDI. There were no associations of either PDI or uPDI with the rate of cognitive decline in either racial group.

CONCLUSIONS

A healthy plant-based diet was associated with a slower rate of decline in global cognition, perceptual speed, and episodic memory in AA adults.

Association of Body Mass Index and Plant-Based Diet with Cognitive Impairment among Older Chinese Adults: A Prospective, Nationwide Cohort Study

To examine the association of body mass index (BMI) and a plant-based diet (PBD) with cognitive impairment in older adults, this cohort study used data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS), a national, community-based, longitudinal, prospective study in China. Cognitive function was evaluated via the Mini-Mental State Examination (MMSE). Diet was assessed using a simplified food frequency questionnaire (FFQ), and PBD patterns were estimated using the overall plant-based diet index (PDI), the healthful plant-based diet index (hPDI), and the unhealthful plant-based diet index (uPDI). BMI was measured objectively during the physical examination. Cox proportional hazard models and restricted cubic spline analyses were used. A total of 4792 participants with normal cognition at baseline were included, and 1077 participants were identified as having developed cognitive impairment during the 24,156 person-years of follow-up. A reverse J-shaped association was observed between BMI and cognitive impairment (p = 0.005 for nonlinearity). Participants who were overweight (HR = 0.79; 95% CI 0.66-0.95) and obese (HR = 0.72; 95% CI 0.54-0.96) had a decreased risk of cognitive impairment, while those who were underweight (HR = 1.42; 95% CI 1.21-1.66) had an increased risk. Lower PDI, lower hPDI, and higher uPDI were associated with an increased risk of cognitive impairment (HR = 1.32; 95% CI 1.16-1.50 for PDI; HR = 1.46; 95% CI 1.29-1.66 for hPDI; HR = 1.21; 95% CI 1.06-1.38 for uPDI). The protective effect of being overweight on cognitive impairment was more pronounced among participants with a higher PDI (HR = 0.74; 95% CI 0.57-0.95) than those with a lower PDI (HR = 0.87; 95% CI 0.67-1.12), among participants with a higher hPDI (HR = 0.73; 95% CI 0.57-0.94) than those with a lower hPDI (HR = 0.93; 95% CI 0.72-1.10), and among participants with a lower uPDI (HR = 0.61; 95% CI 0.46-0.80) than those with a higher uPDI (HR = 1.01; 95% CI 0.80-1.27). Our results support the positive associations of overweight status, obesity, an overall PBD, and a healthful PBD with cognitive function in older adults. A lower adherence to an overall PBD, a healthful PBD, and a higher adherence to an unhealthful PBD may attenuate the protective effect of being overweight on cognitive function.

Plant and Animal Protein Intakes Largely Explain the Nutritional Quality and Health Value of Diets Higher in Plants: A Path Analysis in French Adults

Diets higher in plants are associated with lower risks of chronic diseases. However, animal foods, which are rich in protein, are also rich in some important minerals and vitamins. Using data from a representative survey in France (INCA3, n = 1,125), we used path analyses as a mediation-like approach to decipher the importance of plant and animal proteins in the relationship between the plant-based diet index (PDI) and diet quality. We used three types of diet quality scores, namely, nutrient security, positive nutrient adequacy, and long-term mortality risk of four diet-related diseases (i.e., coronary heart disease, stroke, type 2 diabetes, and colorectal cancer). We identified positive and negative mediations, i.e., changes in plant/animal protein intake that are associated with changes in PDI, and favor or limit the association with the diet quality score. The PDI was positively associated with the risk of long-term mortality but not significantly with nutrient adequacy or nutrient security. A positive mediation by plant protein was found for all diet quality scores (specific indirect effects (SIEs) ranging from 0.04 to 0.10 SD). Conversely, the association between PDI and nutrient adequacy (but not nutrient security) was negatively mediated by animal protein intake (SIE: −0.06 SD). In further detailed models, the association between PDI and diet quality was mainly positively mediated by protein foods from the fruit-vegetables-legumes group (0.01 SD for the nutrient security and 0.02 SD for the nutrient adequacy) and whole grains (0.02 SD for the nutrient adequacy). Our data suggest that the positive impact of plant-based diets on diet quality is largely driven by higher intakes of plant protein foods, especially from fruits-vegetables-legumes and whole grains. Conversely, lower animal protein intake tends to limit the positive impact of plant-based diets on overall positive nutrient adequacy but not security. Protein sources appear critical to healthy plant-based diets.

Vegetarianism, Microbiota and Cardiovascular health: Looking back, and forward

Cardiovascular diseases (CVD) are the leading cause of death globally, with over 17.9 million attributed deaths in 2019. Unhealthy diet is an often-overlooked major modifiable risk factor for CVD. Global Burden of Disease (GBD) estimates suggest that unhealthy diets account for nearly 26% of all deaths, of which 84% were attributed to CVD. Plant-based diets (PBDs), which are a diverse group of dietary patterns focused on plant produce, with flexibility for varying levels of vegetarianism, have been suggested to decrease the incidence of various cardiovascular and cardiometabolic diseases. In this review, we aim to delve into the spectrum of PBDs, revisit objective definitions and classifications, and compare them with standard non-vegetarian diets. We examine plausible mechanisms underlying the cardiovascular benefits of PBDs with a particular focus on the dietary manipulation of gut microbiota-host interaction and its effect on energy metabolism, and local and systemic inflammation. In addition, we explore the evidence on the impact of PBDs on cardiovascular disease, examine the challenges and limitations associated with dietary intervention studies, and devise strategies to draw valid conclusions. Dietary interventions, such as PBDs are one of the most powerful, attainable, cost-effective tools for health and environmental protection at the population level. We conclude with a clear appreciation for PBDs in environmental sustainability, climate change, and animal welfare.

The Association Between Plant-Based Diet Indices and Obesity and Metabolic Diseases in Chinese Adults: Longitudinal Analyses From the China Health and Nutrition Survey

Background

A wide range of health benefits are associated with consuming a diet high in plant-based foods. Diet quality can be accurately assessed using plant-based diet indices, however there is inadequate evidence that plant-based diet indices are linked to obesity, hypertension, and type 2 diabetes (T2D), especially in Chinese cultures who have traditionally consumed plant-rich foods.

Methods

The data came from the China Nutrition and Health Survey. Overall, 11,580 adult participants were enrolled between 2004 and 2006 and followed up until 2009 or 2015 (follow-up rate: 73.4%). Dietary intake was assessed across three 24-h recalls, and two plant-based dietary indices [overall plant-based diet indice (PDI) and healthy plant-based diet indice (hPDI)] were calculated using China Food Composition Code and categorized into quintiles. The study's endpoints were overweight/obesity, hypertension, and T2D. The Hazard ratio (HR) and dose-response relationship were assessed using the Cox proportional risk model and restricted cubic splines. The areas under the curve of the receiver operating characteristic curve analyses were used to evaluate the predictive performance of the PDI and hPDI.

Results

During the median follow-up period of more than 10 years, 1,270 (33.4%), 1,509 (31.6%), and 720 (11.5%) participants developed overweight / obesity, hypertension, and T2D, respectively. The higher PDI score was linked with a reduced risk of overweight/obesity [HR: 0.71 (95% CI: 0.55–0.93), P-trend <0.001], hypertension [HR: 0.63 (95% CI: 0.51–0.79), P-trend <0.001], and T2D [HR: 0.79 (95% CI: 0.72–0.87), P-trend <0.001]. The hPDI score was inversely associated with overweight/obesity [HR: 0.79 (95% CI: 0.62–0.98), P-trend = 0.02] and T2D [HR: 0.84 (95% CI: 0.75–0.93), P-trend = 0.001]. In the aged <55-year-old group, subgroup analysis indicated a significant negative association between PDI/hPDI and overweight/obesity, hypertension, and T2D. There was no significant difference in the areas under the curve of the fully adjusted obesity, hypertension, and diabetes prediction models between PDI and hPDI.

Conclusion

The PDI and hPDI scores were very similar in application in Chinese populations, and our findings highlight that adherence to overall plant-based diet index helps to reduce the risk of T2D, obesity, and hypertension in Chinese adults who habitually consume plant-based foods, especially for those aged <55 year. Further understanding of how plant-based diet quality is associated with chronic disease will be needed in the future, which will help develop dietary strategies to prevent diabetes, hypertension, and related chronic diseases.

High-quality diet, physical activity, and college education are associated with low risk of NAFLD among the US population

BACKGROUND AND AIMS

The effects of diet quality (DQ), physical activity (PA), and socioeconomic status (SES) on the risk of NAFLD are unclear. We examined the association among DQ, PA, SES, and NAFLD risk.

APPROACH AND RESULTS

This is a cross-sectional analysis of the National Health and Nutrition Examination Surveys, 2017-2018, which included 3589 participants with reliable information on vibration-controlled transient elastography (VCTE) measurements, 24-h dietary recalls, PA, and SES. DQ was assessed by the Healthy Eating Index (HEI)-2015. PA was determined by the Global Physical Activity Questionnaire. SES was assessed by the educational attainment and family poverty income ratio (PIR). Risk of NAFLD was considered by means of a composite outcome using VCTE measurements: non-NAFLD versus NAFLD without clinically significant fibrosis (CSF) versus NAFLD with CSF. The NAFLD risk was lower in physically active (≥600 metabolic equivalent of task [MET] min/week) versus inactive participants (<600 MET min/week) (OR: 0.71, p = 0.043). A high-quality diet (HQD) (HEI > 56.64) was associated with a lower risk of NAFLD (OR: 0.58, p < 0.01) compared with a non-HQD. The lowest NAFLD risk was observed in those physically active with HQD (OR: 0.43, p < 0.01). Body mass index and waist circumference significantly mediated the effect of DQ and PA on NAFLD risk. Education (college or above) (OR: 0.65, p = 0.034), but not PIR, was associated with a reduced NAFLD risk. HQD and increased PA partially mediated the effect of education on NAFLD risk. The total effect of education on NAFLD risk mediated by DQ was 29% and by PA was 8%.

CONCLUSIONS

HQD, increased physical activity, and college education were associated with lower NAFLD risk in the US population.

Degree of Adherence to Based Diet and Total and Cause-Specific Mortality: Prospective Cohort Study in the Million Veteran Program

OBJECTIVE

To examine the associations between adherence to plant-based diets and mortality.

DESIGN

prospective study. We calculated a plant-based diet index (PDI) by assigning positive scores to plant foods and reverse scores to animal foods. We also created a healthful PDI (hPDI) and an unhealthful PDI (uPDI) by further separate the healthy plant foods from less-healthy plant foods.

SETTING

the VA Million Veteran Program.

PARTICIPANTS

315,919 men and women aged 19 to 104 years who completed a food frequency questionnaire at the baseline.

RESULTS

We documented 31,136 deaths during the follow-up. A higher PDI was significantly associated with lower total mortality [hazard ratio (HR) comparing extreme deciles =0.75, 95% confidence interval (CI): 0.71 to 0.79, Ptrend <0.001]. We observed an inverse association between hPDI and total mortality (HR comparing extreme deciles =0.64, 95% CI: 0.61 to 0.68, Ptrend <0.001), whereas uPDI was positively associated with total mortality (HR comparing extreme deciles =1.41, 95% CI: 1.33 to 1.49, Ptrend <0.001). Similar significant associations of PDI, hPDI, and uPDI were also observed for CVD and cancer mortality. The associations between the plant-based diet indices and total mortality were consistent among African and European American participants, and participants free from CVD and cancer and those who were diagnosed with major chronic disease at baseline.

CONCLUSIONS

A greater adherence to a plant-based diet was associated with substantially lower total mortality in this large population of veterans. These findings support recommending plant-rich dietary patterns for the prevention of major chronic diseases.

Plant-based dietary patterns in relation to mortality among older adults in China

A plant-based dietary pattern has been recommended for its potential health and environmental benefits, but its relation to mortality warrants further exploration1. We examined this association among 13,154 adults aged 65 years and older (57.4% female) in the Chinese Longitudinal Healthy Longevity Survey (CLHLS). The overall plant-based diet index (PDI), healthful plant-based diet index (hPDI) and unhealthful plant-based diet index (uPDI) were calculated using dietary data collected by a simplified food frequency questionnaire (FFQ). Compared with the lowest quintile, participants in the highest quintile of PDI and hPDI had a decreased risk of all-cause mortality (hazard ratio (HR) = 0.92; 95% confidence interval (CI) 0.86, 0.98 for PDI; HR = 0.81, 95% CI, 0.76, 0.87 for hPDI), whereas participants with the highest uPDI scores had a 17% (95% CI, 9%, 26%) increased risk. Among plant foods, fresh fruits, fresh vegetables, legumes, garlic, nuts and tea were the main protective contributors, whereas preserved vegetables and sugar were associated with a higher risk of mortality. These findings support the beneficial roles of overall and healthful plant-based dietary patterns. The quality, and not only quantity, of plant foods should be emphasized in relevant public health recommendations.

Pro-vegetarian food patterns and cardiometabolic risk in the PREDIMED-Plus study: a cross-sectional baseline analysis

PURPOSE

We explored the cross-sectional association between the adherence to three different provegetarian (PVG) food patterns defined as general (gPVG), healthful (hPVG) and unhealthful (uPVG), and the cardiometabolic risk in adults with metabolic syndrome (MetS) of the PREDIMED-Plus randomized intervention study.

METHODS

We performed a cross-sectional analysis of baseline data from 6439 participants of the PREDIMED-Plus randomized intervention study. The gPVG food pattern was built by positively scoring plant foods (vegetables/fruits/legumes/grains/potatoes/nuts/olive oil) and negatively scoring, animal foods (meat and meat products/animal fats/eggs/fish and seafood/dairy products). The hPVG and uPVG were generated from the gPVG by adding four new food groups (tea and coffee/fruit juices/sugar-sweetened beverages/sweets and desserts), splitting grains and potatoes and scoring them differently. Multivariable-adjusted robust linear regression using MM-type estimator was used to assess the association between PVG food patterns and the standardized Metabolic Syndrome score (MetS z-score), a composed index that has been previously used to ascertain the cardiometabolic risk, adjusting for potential confounders.

RESULTS

A higher adherence to the gPVG and hPVG was associated with lower cardiometabolic risk in multivariable models. The regression coefficients for 5th vs. 1st quintile were - 0.16 (95% CI: - 0.33 to 0.01) for gPVG (p trend: 0.015), and - 0.23 (95% CI: - 0.41 to - 0.05) for hPVG (p trend: 0.016). In contrast, a higher adherence to the uPVG was associated with higher cardiometabolic risk, 0.21 (95% CI: 0.04 to 0.38) (p trend: 0.019).

CONCLUSION

Higher adherence to gPVG and hPVG food patterns was generally associated with lower cardiovascular risk, whereas higher adherence to uPVG was associated to higher cardiovascular risk.

Prepregnancy plant-based diets and the risk of gestational diabetes mellitus: a prospective cohort study of 14,926 women

BACKGROUND

Emerging evidence suggests beneficial impacts of plant-based diets on glucose metabolism among generally healthy individuals. Whether adherence to these diets is related to risk of gestational diabetes mellitus (GDM) is unknown.

OBJECTIVES

We aimed to examine associations between plant-based diets and GDM in a large prospective study.

METHODS

We included 14,926 women from the Nurses' Health Study II (1991-2001), who reported ≥1 singleton pregnancy and without previous GDM before the index pregnancy. Prepregnancy adherence to plant-based diets was measured by an overall plant-based diet index (PDI), healthful plant-based diet index (hPDI), and unhealthful plant-based diet index (uPDI) as assessed by FFQs every 4 y. Incident first-time GDM was ascertained from a self-reported physician diagnosis, which was previously validated by review of medical records. We used log-binomial models with generalized estimating equations to calculate RRs and 95% CIs for associations of PDIs with GDM.

RESULTS

We documented 846 incident GDM cases over the 10-y follow-up among 20,707 pregnancies. Greater adherence to the PDI and hPDI was associated with lower GDM risk. For the PDI, the multivariable-adjusted RR (95% CI) comparing the highest and lowest quintiles (Q5 compared with Q1) was 0.70 (0.56, 0.87) (Ptrend = 0.0004), and for each 10-point increment was 0.80 (0.71, 0.90). For the hPDI, the RR (95% CI) of Q5 compared with Q1 was 0.75 (0.59, 0.94) (Ptrend = 0.009) and for each 10-point increment was 0.86 (0.77, 0.95). After further adjustment for prepregnancy BMI, the associations were attenuated but remained significant: for the PDI, the RR (95% CI) for each 10-point increment was 0.89 (0.79, 1.00) and the corresponding RR (95% CI) was 0.89 (0.80, 0.99) for the hPDI. The uPDI was not associated with GDM.

CONCLUSIONS

Our study suggests that greater prepregnancy adherence to a healthful plant-based diet was associated with lower risk of GDM, whereas an unhealthful plant-based diet was not related to GDM risk.

Association between Unhealthful Plant-Based Diets and Possible Risk of Dyslipidemia

The relationship between the various types of diets derived from plants and vulnerability of dyslipidemia has rarely been investigated, and limited data exist in Asians whose dietary pattern is fairly different from that of the Western population. We aim to analyze the relationship between three plant-based diet indices (PDI) and the risk of dyslipidemia. Participants included 173,209 Korean adults who were aged ≥40 years from the Korean Genome and Epidemiology Study_Health Examination (2004–2013). A food frequency questionnaire (FFQ) was used to assess dietary intake. Three PDI were quantified for the study: overall PDI, healthful PDI (hPDI), and unhealthful PDI (uPDI). Among the 147,945 included, 48,166 (32.6%) of participants had dyslipidemia. Great adherence to uPDI was related with 15% greater odds of having dyslipidemia (OR: 1.15; 95% CI: 1.11–1.20, p-trend < 0.0001). No significant association was observed between PDI, hPDI, and dyslipidemia. The association between uPDI and dyslipidemia was significantly stronger among participants aged ≥55 years when compared to participants aged <55 years (p-value for interaction = 0.001). The quality of plant foods is vital in preventing dyslipidemia among people consuming high plant-based food diets.

Reproducibility and validity of diet quality scores derived from food-frequency questionnaires

BACKGROUND

Diet quality scores (DQSs) are frequently used to study diet-disease relations but the validity of these scores derived from FFQs has rarely been evaluated.

OBJECTIVES

To evaluate the validity and reproducibility of 6 commonly used DQSs derived from the FFQ, including the Alternate Healthy Eating Index-2010, Dietary Approaches to Stop Hypertension Trial score, alternative Mediterranean diet score, and 3 plant-based diet indices (overall, healthful, and unhealthful).

METHODS

This analysis included 1394 participants from the Men's Lifestyle Validation Study (N = 652) and the Women's Lifestyle Validation Study (N = 742). Participants completed a 152-item FFQ at the beginning of the study and 1 y later, as well as completed 2 weighed 7-d dietary records (7DDRs) and donated 2 blood samples 6 mo apart between FFQ assessments. The reproducibility of the FFQs was evaluated by rank intraclass correlation coefficients (ICCs). The validity was assessed by comparing FFQ-derived DQSs with those from the average of two 7DDRs using Spearman rank correlation coefficients deattenuated for random measurement error in the 7DDRs (rs). Furthermore, we calculated the correlations between DQSs and plasma biomarkers of diet, including fatty acids, folate, carotenoids, retinol, and α- and γ-tocopherol.

RESULTS

Six FFQ-derived DQSs demonstrated moderate to high reproducibility (energy-adjusted ICCs: 0.61-0.84) and validity (energy-adjusted, deattenuated rs = 0.56-0.80) in both men and women. We consistently observed expected correlations between FFQ-derived DQSs with plasma fatty acids, including long-chain n-3 (ω-3) and trans fatty acids, most carotenoids, and γ-tocopherol (rs > 0.2).

CONCLUSIONS

Our study demonstrates the validity of the FFQ to evaluate overall diet quality using 6 commonly used DQSs. In addition, these DQSs have qualitatively demonstrated biological relevance, as indicated by their correlations with circulating biomarkers.

Adherence to a Plant-Based Diet and Consumption of Specific Plant Foods-Associations with 3-Year Weight-Loss Maintenance and Cardiometabolic Risk Factors: A Secondary Analysis of the PREVIEW Intervention Study

Plant-based diets are recommended by dietary guidelines. This secondary analysis aimed to assess longitudinal associations of an overall plant-based diet and specific plant foods with weight-loss maintenance and cardiometabolic risk factors. Longitudinal data on 710 participants (aged 26–70 years) with overweight or obesity and pre-diabetes from the 3-year weight-loss maintenance phase of the PREVIEW intervention were analyzed. Adherence to an overall plant-based diet was evaluated using a novel plant-based diet index, where all plant-based foods received positive scores and all animal-based foods received negative scores. After adjustment for potential confounders, linear mixed models with repeated measures showed that the plant-based diet index was inversely associated with weight regain, but not with cardiometabolic risk factors. Nut intake was inversely associated with regain of weight and fat mass and increments in total cholesterol and LDL cholesterol. Fruit intake was inversely associated with increments in diastolic blood pressure, total cholesterol, and LDL cholesterol. Vegetable intake was inversely associated with an increment in diastolic blood pressure and triglycerides and was positively associated with an increase in HDL cholesterol. All reported associations with cardiometabolic risk factors were independent of weight change. Long-term consumption of nuts, fruits, and vegetables may be beneficial for weight management and cardiometabolic health, whereas an overall plant-based diet may improve weight management only.

Plant-based diet quality and the risk of total and disease-specific mortality: A population-based prospective study

BACKGROUND AND AIMS

Plant-based diets have been suggested to have health benefits, and risk differs by quality of plant foods. However, evidence on the association between the quality of plant-based diets and mortality are limited. This study examined the associations between 3 different types of plant-based diet indices and risk of total and disease-specific mortality.

METHODS

Analyses were based on a population-based cohort of 118,577 South Korean adults (40-69 years of age) who participated in the Korean Genome and Epidemiology Study_Health Examinees (2004-2019). Dietary intakes were assessed using a validated food frequency questionnaire. Based on the questionnaire, we calculated 3 plant-based diet indices: overall plant-based diet index (PDI), healthful plant-based diet index (hPDI), and unhealthful plant-based diet index (uPDI). The PDI assigned higher scores for higher consumption of all plant foods. The hPDI assigned higher scores for higher consumption of only healthy plant foods. The uPDI assigned higher scores for higher consumption of only unhealthy plant foods.

RESULTS

During a total of 1,191,426 person-years of follow-up, we ascertained 3074 deaths, including 447 deaths from cardiovascular disease and 1515 deaths from cancer. Comparing the highest versus lowest quintiles of PDI, the multivariable-adjusted hazard ratios of total mortality were 0.76 (95% CI, 0.68-0.85, P-trend<0.0001). Comparing the highest versus lowest quintile of uPDI, the hazard ratios were 1.30 for total mortality (95% CI, 1.15-1.48, P-trend<0.0001), 1.55 for cardiovascular disease mortality (95% CI, 1.08-2.25, P-trend = 0.06), and 1.23 for cancer mortality (95% CI, 1.02-1.47, P-trend = 0.06) after adjustment for demographic characteristics and lifestyle factors. For 10-point higher in PDI score was associated with 13% (95% CI, 0.82-0.92, P < 0.0001) lower risk of total mortality. In contrast, 10-point higher in uPDI score was associated with 16% (95% CI, 1.06-1.17, P < 0.0001) higher risk of total mortality with modest association with cancer mortality. No association was observed between hPDI and any cause of mortality. The correlation coefficients were 0.39 between PDI and hPDI, -0.22 between hPDI and uPDI, and 0.07 between PDI and uPDI.

CONCLUSIONS

Overall, greater adherence to a plant-based dietary pattern was associated with lower total mortality, but among those with predominantly unhealthful plant-based diets, total and disease-specific mortality rates were higher. The quality of plant foods may be crucial for reducing mortality in a population that mainly consume diets rich in plant foods.

BMI in the Associations of Plant-Based Diets with Type 2 Diabetes and Hypertension Risks in Women: The E3N Prospective Cohort Study

BACKGROUND

Few studies have evaluated the quality of plant-based diets in relation to chronic diseases, and the potential role of BMI is not clearly explored.

OBJECTIVES

To study the associations between plant-based diet indices and type 2 diabetes (T2D) and hypertension risks, as well as the extent to which the associations were modified and/or mediated by BMI.

METHODS

The study included 74,522 women from the Etude Epidémiologique auprès de femmes de la Mutuelle Générale de l'Education Nationale prospective cohort [mean (SD): age, 52.94 (6.7) years; BMI, 22.970 (3.328) kg/m2]. Dietary data were collected at baseline (1993) via an FFQ. Overall plant-based diet index (PDI), healthful PDI (hPDI), and unhealthful PDI (uPDI) were developed. Multivariable Cox regression models were used to derive HRs and 95% CIs. Effect modification and mediation by BMI were explored.

RESULTS

There were 3292 (4.64%) incident cases of T2D and 12,504 (27.14%) incident cases of hypertension over ∼20 years of follow-up. In the multivariable model further adjusted for BMI, higher adherence to PDI and hPDI was associated with lower T2D and hypertension risks, with an HR per 1-SD increase (95% CI) of 0.88 (0.85, 0.91) and 0.96 (0.94, 0.98) for PDI and 0.88 (0.85, 0.92) and 0.94 (0.92, 0.95) for hPDI, respectively. uPDI was not associated with T2D [0.98 (0.94, 1.01)], whereas a positive association was observed with hypertension: 1.04 (1.02, 1.06). There was interaction between PDI and uPDI, as well as BMI, on T2D (P-interaction < 0.001) but not on hypertension (P-interaction > 0.05). In addition, BMI mediated 26-59% and 0.2-59% of diet-T2D and diet-hypertension associations, respectively.

CONCLUSIONS

Differential associations between plant-based diets and T2D and hypertension risks were observed among women in this large prospective study. Only healthier plant foods were associated with lower risks, partly through decreasing BMI. The protocol was registered at clinicaltrials.gov as NCT03285230.

Association of plant-based diet index with inflammatory markers and sleep quality in overweight and obese female adults: A cross-sectional study

BACKGROUND

Inflammation and sleep disturbances increase the risk of multiple diseases, including cardiovascular disease, type 2 diabetes and dementia. Since diet plays a significant role in inflammatory responses and sleep quality, this study aimed to investigate the association of a plant-based diet index (PDI) with sleep quality and inflammatory markers in overweight and obese women.

METHODS

390 overweight and obese women aged 18-48 years participated in this cross-sectional study. A validated food frequency questionnaire (FFQ) was used to create an overall PDI, healthful plant-based diet index (hPDI) and unhealthful plant-based diet index (uPDI). Sleep quality was assessed by Pittsburgh Sleep Quality Index (PSQI). Higher scores on the PSQI were indicative of poor sleep. Anthropometric measurements and serum concentrations of high-sensitivity C-reactive protein (hs-CRP), interleukin 1 beta (IL-1β) and transforming growth factor-beta (TGF-β) were evaluated. Linear regression models were used to determine the association between exposure and outcomes.

RESULTS

After taking potential confounders into account, we found a significant inverse association between adherence to hPDI and hs-CRP (β = -0.14, 95% confidence interval [CI]: -0.22,0.06, P = .001) and a significant positive association between uPDI and hs-CRP (β = 0.13, 95% CI: 0.05,0.21, P = .001). Overall, PDI was significantly associated with TGF-β (β = 2.04, 95% CI: 0.54,3.55, P = .008). No association was detected between PDI indices and IL-1β. Higher adherence to uPDI was significantly associated with higher PSQI score (lower sleep quality) (β= 0.20, 95% CI:0.007,0.40, P = .04). A significant positive association was found between TGF-β (β = 0.05, 95% CI:0.005,0.10, P = .03) and hs-CRP (β = 0.32, 95% CI:0.02,0.62, P = .03) with PSQI.

CONCLUSION

Our findings indicated a significant association between adherence to a plant-based diet with inflammation and sleep quality in obese and overweight females. WHAT IS ALREADY KNOWN ABOUT THIS TOPIC?: Sleep is an essential part of life, and sleep quality has a significant impact on individual well-being and performance. There is a bidirectional relationship between disturbed sleep and elevated levels of inflammatory markers. Diet plays a major part in sleep quality and its related health consequences. Plant-based diets are associated with lower risk of chronic diseases such as coronary artery disease (CAD), type 2 diabetes, obesity and reduced level of inflammation. WHAT DOES THIS ARTICLE ADD?: Adherence to a healthful plant-based diet is associated with lower level of hs-CRP, while adherence to an unhealthful plant-based diet is associated with higher concentrations of hs-CRP. Adherence to an unhealthful plant-based diet is associated with lower sleep quality.