Association of plant-based diets with total and cause-specific mortality across socioeconomic deprivation level: a large prospective cohort

PURPOSE

Current evidence on the association between plant-based diet indices (PDIs) and mortality is inconsistent. We aimed to investigate the association of PDIs with all-cause and cause-specific mortality and to examine whether such associations were modified by socioeconomic deprivation level.

METHODS

A total of 189,003 UK Biobank participants with at least one 24-h dietary assessment were included. All food items were categorised into three groups, including healthy plant foods, less healthy plant foods, and animal foods. Three PDIs, including the overall PDI (positive scores for all plant-based food intake and inverse scores for animal-based foods), the healthful PDI (hPDI) (positive scores only for healthy plant food intake and inverse scores for others), and the unhealthful PDI (uPDI) (positive scores only for less healthy plant food intake and inverse scores for others), were calculated according to the quantities of each food subgroup in three categories. The Townsend deprivation index was used as the indicator of socioeconomic deprivation level. Cox proportional hazard models were used to estimate the hazard ratios (HRs) of PDIs for all-cause and cause-specific mortality. The modification effects of socioeconomic deprivation levels on these associations were evaluated.

RESULTS

During a median follow-up of 9.6 years, 9335 deaths were documented. Compared with the lowest quintile, the highest quintile of overall PDI was associated with adjusted HRs of 0.87 (95% CI 0.81-0.93) for all-cause mortality and 0.77 (0.66-0.91) for cardiovascular mortality. Compared with the lowest quintile, the highest quintile of hPDI was associated with lower risks of all-cause mortality (0.92, 0.86-0.98), and death caused by respiratory disease (0.63, 0.47-0.86), neurological disease (0.65, 0.48-0.88), and cancer (0.90, 0.82-0.99). Compared with the lowest quintile, the highest quintile of uPDI was associated with an HR of 1.29 (1.20-1.38) for all-cause mortality, 1.95 (1.40-2.73) for neurological mortality, 1.54 (1.13-2.09) for respiratory mortality, and 1.16 (1.06-1.27) for cancer mortality. The magnitudes of associations of hPDI and uPDI with mortality were larger in the most socioeconomically deprived participants (the highest tertile) than in the less deprived ones (p-values for interaction were 0.039 and 0.001, respectively).

CONCLUSIONS

This study showed that having a high overall PDI and hPDI were related to a reduced risk of death, while the uPDI was linked to a higher risk of death. Sticking to a healthy plant-based diet may help decrease mortality risks across socioeconomic deprivation levels, especially for those who are the most socioeconomically deprived.

Unraveling the role of serum metabolites in the relationship between plant-based diets and bone health in community-dwelling older adults

The potential adverse effects of the plant-based dietary pattern on bone health have received widespread attention. However, the biological mechanisms underlying the adverse effects of plant-based diets on bone health remain incompletely understood. The objective of this study was to identify potential biomarkers between plant-based diets and bone loss utilizing metabolomic techniques in the Taizhou Imaging Study (TIS) (N = 788). Plant-based diet indexes (overall plant-based diet index (PDI), healthy plant-based diet index (hPDI), and unhealthy plant-based diet index (uPDI)) were calculated using the food frequency questionnaire, and bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry. A multinomial logistic regression was used to explore the associations of plant-based diet indexes with bone loss. Furthermore, mediation analysis and exploratory factor analysis (EFA) were performed to explore the mediated effects of metabolites on the association of plant-based diets with BMD T-score. Our results showed that higher hPDI and uPDI were positively associated with bone loss. Moreover, nineteen metabolites were significantly associated with BMD T-score, among them, seven metabolites were associated with uPDI. Except for cholesterol esters in VLDL-1, the remaining six metabolites significantly mediated the negative association between uPDI and BMD T-score. Interestingly, we observed that the same six metabolites mediated the positive association between fresh fruit and BMD T-score. Collectively, our results support the deleterious effects of plant-based diets on bone health and discover the potential mediation effect of metabolites on the association of plant-based diets with bone loss. The findings offer valuable insights that could optimize dietary recommendations and interventions, contributing to alleviate the potential adverse effects associated with plant-based diets.

A healthful plant-based diet is associated with lower type 2 diabetes risk via improved metabolic state and organ function: A prospective cohort study

BACKGROUND

Plant-based diets are becoming increasingly popular due to favourable environmental footprints and have been associated with lower risk of type 2 diabetes mellitus (T2DM). Here, we investigated the potential mechanisms to explain the lower T2DM risk observed among individuals following plant-based diets.

METHODS

Prospective data from the UK Biobank, a cohort study of participants aged 40 to 69 years at baseline, was evaluated. Associations between healthful and unhealthful plant-based indices (hPDI and uPDI) and T2DM risk were analysed by multivariable Cox regression models, followed by causal mediation analyses to investigate which cardiometabolic risk factors explained the observed associations.

RESULTS

Of 113,097 study participants 2,628 developed T2DM over 12 years of follow-up. Participants with the highest hPDI scores (Quartile 4) had a 24 % lower T2DM risk compared to those with the lowest scores (Quartile 1) [Hazard Ratio (HR): 0.76, 95 % Confidence Interval (CI): 0.68-0.85]. This association was mediated by a lower BMI (proportion mediated: 28 %), lower waist circumference (28 %), and lower concentrations of HBA1c (11 %), triglycerides (9 %), alanine aminotransferase (5 %), gamma glutamyl transferase (4 %), C-reactive protein (4 %), insulin-like growth factor 1 (4 %), cystatin C (4 %) and urate (4 %). Higher uPDI scores were associated with a 37 % higher T2DM risk [HR: 1.37, 95 % CI:1.22- 1.53], with higher waist circumference (proportion mediated: 17 %), BMI (7 %), and higher concentrations of triglycerides (13 %) potentially playing mediating roles.

CONCLUSION

Healthful plant-based diets may protect against T2DM via lower body fatness, but also via normoglycaemia, lower basal inflammation as well as improved kidney and liver function.

Association between plant-based dietary pattern and biological aging trajectory in a large prospective cohort

BACKGROUND

Aging is a dynamic and heterogeneous process that may better be captured by trajectories of aging biomarkers. Biological age has been advocated as a better biomarker of aging than chronological age, and plant-based dietary patterns have been found to be linked to aging. However, the associations of biological age trajectories with mortality and plant-based dietary patterns remained unclear.

METHODS

Using group-based trajectory modeling approach, we identified distinctive aging trajectory groups among 12,784 participants based on a recently developed biological aging measure acquired at four-time points within an 8-year period. We then examined associations between aging trajectories and quintiles of plant-based dietary patterns assessed by overall plant-based diet index (PDI), healthful PDI (hPDI), and unhealthful PDI (uPDI) among 10,191 participants who had complete data on dietary intake, using multivariable multinomial logistics regression adjusting for sociodemographic and lifestyles factors. Cox proportional hazards regression models were applied to investigate the association between aging trajectories and all-cause mortality.

RESULTS

We identified three latent classes of accelerated aging trajectories: slow aging, medium-degree, and high-degree accelerated aging trajectories. Participants who had higher PDI or hPDI had lower odds of being in medium-degree (OR = 0.75, 95% CI: 0.65, 0.86 for PDI; OR = 0.73, 95% CI: 0.62, 0.85 for hPDI) or high-degree (OR = 0.63, 95% CI: 0.46, 0.86 for PDI; OR = 0.62, 95% CI: 0.44, 0.88 for hPDI) accelerated aging trajectories. Participants in the highest quintile of uPDI were more likely to be in medium-degree (OR = 1.72, 95% CI: 1.48, 1.99) or high-degree (OR = 1.70, 95% CI: 1.21, 2.38) accelerated aging trajectories. With a mean follow-up time of 8.40 years and 803 (6.28%) participants died by the end of follow-up, we found that participants in medium-degree (HR = 1.56, 95% CI: 1.29, 1.89) or high-degree (HR = 3.72, 95% CI: 2.73, 5.08) accelerated aging trajectory groups had higher risks of death than those in the slow aging trajectory.

CONCLUSIONS

We identified three distinctive aging trajectories in a large Asian cohort and found that adopting a plant-based dietary pattern, especially when rich in healthful plant foods, was associated with substantially lowered pace of aging.

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.

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.

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.

Plasma boron concentrations in the general population: a cross-sectional analysis of cardio-metabolic and dietary correlates

Purpose

Experimental evidence suggests positive effects of boron on health and metabolism, but human data are still scarce. We aimed to identify dietary and cardio-metabolic correlates of plasma boron concentrations in the general population.

Methods

In a community-based sample (n = 899, 57% men, mean age 61 years), plasma boron (median [IQR]: 33.80 µg/L [25.61; 44.65]) concentrations were measured by inductively coupled plasma-mass spectrometry. Overall (PDI), healthy (hPDI), and unhealthy (uPDI) plant-based diet indices were derived from a validated food frequency questionnaire. Reduced rank regression (RRR) yielded a dietary pattern explaining 30% of the variation of circulating boron. Cross-sectional associations of dietary indices and cardio-metabolic traits with plasma boron concentrations were assessed using multivariable-adjusted linear regression analysis.

Results

The RRR pattern was characterized by high intake of fruits, nuts/seeds, tea, wine and low intake of e.g. bread, poultry, processed meat, chocolate/sweets, and soft drinks. 10-point increments in PDI, hPDI, and uPDI were associated with 8.7% (95% CI: 4.2; 13.4), 10.4% (95% CI: 6.6; 14.3), and −8.8% (95% CI: −12.1; −5.4) change in plasma boron concentrations, respectively. Age and phosphate were directly, while BMI, plasma lipid concentrations, and CRP were inversely associated with circulating boron. Plasma boron concentrations were higher in summer vs. winter, in individuals taking vs. not taking antihypertensive medication, and in individuals with high or medium vs. low education level.

Conclusion

Higher plasma boron concentrations appeared to associate with a healthier diet, were related to lower BMI and a more favorable cardio-metabolic risk profile, and showed seasonal variations.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02730-w.

The association between plant-based diet indices and metabolic syndrome in Iranian older adults

BACKGROUND

We investigated the association between plant-based diets indices - an overall plant-based diet index; a healthful plant-based diet index; and an unhealthful plant-based diet index - and metabolic syndrome among Iranian older adults.

AIM

We aimed to examine the relationship between plant-based diet indices and metabolic syndrome.

METHODS

This cross-sectional study included 178 older adults (51 men and 127 women), with a mean age of 67.04 (60-83) who were referred to health centers in Tehran, Iran. Blood and urine samples were collected to measure serum total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides. We created an overall plant-based diet index, healthful plant-based diet index, and unhealthful plant-based diet index from semi-quantitative food-frequency questionnaire data. Anthropometric measures were done.

RESULTS

Our crude model results showed that triglycerides, systolic and diastolic blood pressure, fasting blood sugar, high-density lipoprotein cholesterol, and waist circumference did not significantly differ between tertiles of plant-based diet index and healthful plant-based diet index; also triglycerides, systolic and diastolic blood pressure, fasting blood sugar, and waist circumference did not significantly differ between tertiles of unhealthful plant-based diet index, but high-density lipoprotein cholesterol significantly differed between tertiles of unhealthful plant-based diet index. After adjusting for confounders the results remained non-significant for plant-based diet index but high-density lipoprotein cholesterol was significant for healthful and unhealthful plant-based diet indices. There was also no significant association between plant-based diet index (OR: 1.11; 95% CI: 0.53-2.33), healthful plant-based diet index (OR: 0.81; 95% CI: 0.39-1.68), and unhealthful plant-based diet index (OR: 0.81; 95% CI: 0.38-1.72) with metabolic syndrome, even after adjustment for confounders.

CONCLUSIONS

Our findings showed that plant-based diets are not significantly associated with risk of metabolic syndrome in older adults. To confirm the veracity of these findings, more studies should be conducted.

The association of plant-based dietary patterns with visceral adiposity, lipid accumulation product, and triglyceride-glucose index in Iranian adults

BACKGROUND

We sought to investigate whether adherence to a more plant-based, and less animal-based, diet is associated with visceral adiposity, lipid accumulation product (LAP), and triglyceride-glucose index (TyG) in Iranian adults.

METHODS

This cross-sectional study was conducted on 270 adults aged between 18-75 years old. We created three plant-based diets. including an overall plant-based diet index (PDI), hPDI, and uPDI based on tertiles regarding the intake of animal- or plant-based food items obtained from a semi quantitative food-frequency questionnaire.

RESULTS

Higher hPDI was significantly associated with lower body mass index (BMI) (P-value = 0.01), lower waist circumference (P-value<0.001), and lower waist-hip ratio (P-value<0.001). A significant increase was found for high density lipoproteins (HDL) (P-trend <0.001) with a significant decrease for LAP (P-value = 0.03) in those with higher adherence to hPDI. Moreover, greater adherence to PDI was associated with a significant increase in diastolic blood pressure (DBP) (p-value = 0.01) and fat free mass (FFM) (p-value = 0.01). There were no significant associations between PDIs and TyG and VFA.

CONCLUSION

We found that a higher hPDI score was significantly associated with better anthropometric measurements. A significant increase was found for HDL and a significant decrease was found for LAP on hPDI. However, a higher PDI score was significantly associated with higher DBP and higher FFM.

Association of dietary acid load and plant-based diet index with sleep, stress, anxiety and depression in diabetic women

Diabetes is a common chronic disease with various complications. The present study was conducted to determine the association of plant-based diet index (PDI) and dietary acid load (DAL) with sleep status as well as mental health in type 2 diabetic women. In this cross-sectional study, a validated FFQ was used to assess dietary intakes of 230 diabetic patients. We created a whole PDI, healthful PDI (hPDI) and unhealthful PDI (uPDI). DAL was calculated based on potential renal acid load and net endogenous acid production method. The Pittsburgh Sleep Quality Index and twenty-one-item Depression, Anxiety and Stress Scale were used to assess sleep and mental health disorders, respectively. Participants in the top group of uPDI had greater risk of poor sleep (OR 6·47, 95 % CI 2·75, 15·24). However, patients who were in the top group of hPDI had a lower risk of sleep problems (OR 0·28, 95 % CI 0·13, 0·62). Participants in the top group of uPDI had greater risk of depression, anxiety and stress (OR 9·35, 95 % CI 3·96, 22·07; OR 4·74, 95 % CI 2·28, 9·85; OR 4·24, 95 % CI 2·14, 8·38, respectively). In conclusion, participants with higher DAL scores and patients who adhered to animal-based diets rather than plant-based diets were more likely to be poor sleepers and have mental health disorders.