Quality of plant-based diets in relation to 10-year cardiovascular disease risk: the ATTICA cohort study

Macronutrient composition of plant-based diets and breast cancer risk: the E3N prospective cohort study

PURPOSE

Recent evidence suggests that plant-based diets may reduce the risk of breast cancer (BC). However, the macronutrient composition of plant-based diets and its potential impact on BC risk has not been well explored. This analysis investigated the association of macronutrient composition with BC risk across a spectrum of plant-based diet indexes using a multidimensional approach.

DESIGN

This study followed 64,655 participants from the Etude Epidémiologique auprès de femmes de la Mutuelle Générale de l'Education Nationale (E3N) cohort from 1993 to 2014. Diets were evaluated using validated 208-item diet history questionnaires at baseline (1993) and follow-up (2005), to calculate adherence to the overall plant-based diet (PDI), healthful plant-based diet (hPDI), and unhealthful plant-based diet (uPDI). The association of macronutrient composition with BC risk was assessed via generalized additive time-dependent Cox models across different levels of these indexes. Response surfaces were generated to visualize compositional associations at the 25th, 50th, and 75th percentile of each index (low, moderate, and high).

RESULTS

A total of 3,932 incident BC cases were identified during the 21-year follow-up. There was a significant association between macronutrient composition and BC risk for hPDI, uPDI, and PDI (all P < 0.001). Akaike information criterion favored the hPDI model for characterizing the association between macronutrients and BC. BC risk was highest for individuals with a lower hPDI score who also consumed a diet containing lower protein (10%), lower carbohydrate (35%), and higher fat (55%). The lowest risk of BC was observed in those with higher hPDI scores with the lowest intake of protein (10%). At higher PDI and uPDI, diets containing higher protein (30%) and fat (45%) had the highest BC risk.

CONCLUSION

These results demonstrate a complex relationship between macronutrient composition, plant-based diet quality, and BC risk. Further research is needed to examine specific foods that may be driving these associations.

REGISTRY

The protocol is registered at clinicaltrials.gov as NCT03285230.

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.

Comparative Analysis of Vitamin, Mineral Content, and Antioxidant Capacity in Cereals and Legumes and Influence of Thermal Process

Cereals, as the world's most consumed food, face challenges related to nutrient quality due to climate change and increased production impacting soil health. In this study, we investigated the vitamin and mineral content, polyphenols, and antioxidant activity in cereals from Western Romania, analyzing whole and hulled wheat, rye, oat, and soybeans before and after heat treatment. Samples from 2022 crops were processed into dough and subjected to 220 °C for 30 min. The results reveal that, despite efforts to optimize nutrient content, cereals, particularly after heat processing, exhibited lower vitamin and mineral levels than the recommended daily intake. The decrease in polyphenols and antioxidant capacity was notable, with rye flour experiencing the largest decline (15%). Mineral analysis showed copper levels in decorticated wheat decreased by 82.5%, while iron in rye decreased by 5.63%. Soy flour consistently displayed the highest calcium, magnesium, and potassium levels, whereas oat flour had the highest zinc and copper levels before and after heat processing. The study highlights the concerningly low vitamins and minerals contents in cereals, as well as in the final products reaching consumers in the Western part of Romania, and contributes to the assessment of measures that are meant to improve the contents of these minerals.

Plant-Based Dietary Indices in Relation to Nutrient and Food Group Intakes in Preschool-Aged Children

Dietary guidance promotes plant-based foods, yet minimal research has examined intake in children. This study examined plant-based food intake in preschool-aged children using plant-based dietary index (PDI) metrics and related these metrics to nutrient and food group intakes. Dietary data were collected from preschool-aged children (n = 283, 3.45 ± 1.22 years) from the Guelph Family Health Study at baseline using the Automated Self-Administered 24-Hour Dietary Assessment Tool. Food intake servings were assigned to 16 food groups for calculation of overall PDI (oPDI), healthful PDI (hPDI), and less healthful (lhPDI) scores and summarized into tertiles for energy-adjusted comparisons. For oPDI, participants in the highest vs. lowest tertile had higher intakes of nutrients and food groups to encourage (e.g., dietary fiber, fruits) as well as lower intakes of nutrients to encourage (e.g., calcium, vitamin D). For hPDI, participants in the highest vs. lowest tertile had higher intakes of nutrients and food groups to encourage and lower intakes of those to limit (e.g., saturated fat, sweets and desserts). For lhPDI, participants in the highest vs. lowest tertile had higher intakes of nutrients and food groups to limit and lower intakes of those to encourage. These results can inform dietetic practice for dietary guidance that promotes plant-based foods in children.

Adherence to a modified nordic diet and the risk of cardiovascular events in a non-nordic population: a prospective cohort study

BACKGROUND

Even though studies have demonstrated that the Nordic diet is beneficial for cardiovascular disease (CVD) risk factors, it is unknown if this diet is associated with actual CVD cases. So, the aim of this study was to investigate the association between a modified Nordic diet and the risk of CVD in non-Nordic adults.

METHODS

In this cohort study, 2918 people who participated in the third phase of the Tehran Lipid and Glucose Study (TLGS) were examined. All participants had no CVD at the beginning of the study, which was monitored until 2018. The Nordic score was calculated using a validated food frequency questionnaire (FFQ). Patients' medical records were examined for cardiovascular events such as coronary heart disease (CHD), stroke, and mortality from CVD. The Cox proportional hazards model was used to assess the relationship between the Nordic score and the risk of CVD.

RESULTS

During a median follow-up of 10.6 years, 203 subjects experienced cardiovascular events. The third and fourth quartiles of the Nordic score were associated with a 35% (HR: 0.65; 95% CI: 0.45, 0.95) and 60% (HR: 0.40; 95% CI: 0.27 to 0.65) reduced risk of CVD compared to the lowest quartile. Subgroup analyses revealed that a high Nordic score was inversely associated with a lower risk of CVD in adults older than 45 years of age, both sexes, and all BMI categories. Each 1-score increase in cereal consumption was associated with a 24% (HR: 0.76; 95% CI: 0.67 to 0.87) lower risk of CVD; low-fat milk with a 23% (HR: 0.77; 95% CI: 0.68 to 0.87); and fish with a 22% (HR: 0.78; 95% CI: 0.69 to 0.89) lower risk of CVD.

CONCLUSION

We found that high Nordic score adherence may prevent cardiovascular events in non-Nordic populations. Cereals, fish, and low-fat milk were the primary components of the Nordic diet that indicated an inverse relationship with CVD.

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.

Plant-Based Dietary Patterns and Cardiovascular Disease Risk in Australians: Protocol for a Cross-Sectional Study

Plant-based diets (PBDs) emphasise higher intakes of plant foods and lower intakes of animal foods, and they have been associated with reduced cardiovascular morbidity/mortality and lower cardiovascular disease (CVD) risk factors. Evidence is limited regarding the dietary profile, diet quality, and nutritional adequacy of PBDs, including their impact on CVD risk compared with traditional meat-eating diets in Australians. The PBD Study (PBDS) is a cross-sectional study that will recruit 240 adults from the Hunter region (NSW) without known CVD who are habitually consuming vegan (no animal flesh/animal products), lacto-ovo vegetarian (dairy and/or eggs only), pesco-vegetarian (fish/seafood only), or semi-vegetarian (minimal animal flesh) diets or are a regular meat-eater. To investigate dietary profile, diet quality, nutritional adequacy, and CVD risk, questionnaires (medical history, demographics, and physical activity), blood samples (biomarkers), physical measures (anthropometry, blood pressure, body composition, and bone density), and dietary intake (food frequency questionnaire and diet history) will be collected. One-way ANOVA and Kruskal-Wallis tests will compare the CVD risk and other quantitative measures, and Chi-square or Fisher's Exact tests will be used for qualitative data. Directed acyclic graphs will determine the confounding variables, and linear regression and mediation analyses will account for the confounders and estimate the effect of dietary patterns on CVD risk. p-values will be adjusted using the Benjamini-Hochberg method to control the False Discovery Rate to 5%.

Long-term adherence to healthful and unhealthful plant-based diets and breast cancer risk overall and by hormone receptor and histologic subtypes among postmenopausal females

BACKGROUND

Epidemiological studies assessing the influence of vegetarian diets on breast cancer (BC) risk have produced inconsistent results. Few studies have assessed how the incremental decrease in animal foods and the quality of plant foods are linked with BC.

OBJECTIVES

Disentangle the influence of plant-based diet quality on BC risk between postmenopausal females.

METHODS

Total of 65,574 participants from the E3N (Etude Epidémiologique auprès de femmes de la Mutuelle Générale de l'Education Nationale) cohort were followed from 1993-2014. Incident BC cases were confirmed through pathological reports and classified into subtypes. Cumulative average scores for healthful (hPDI) and unhealthful (uPDI) plant-based diet indices were developed using self-reported dietary intakes at baseline (1993) and follow-up (2005) and divided into quintiles. Cox proportional hazards models were used to estimate adjusted HR and 95% CI.

RESULTS

During a mean follow-up of 21 y, 3968 incident postmenopausal BC cases were identified. There was a nonlinear association between adherence to hPDI and BC risk (Pnonlinear < 0.01). Compared to participants with low adherence to hPDI, those with high adherence had a lower BC risk [HRQ3 compared withQ1 (95% CI): 0.79 (0.71, 0.87) and HRQ4 compared with Q1 (95% CI): 0.78 (0.70, 0.86)]. In contrast, higher adherence to unhealthful was associated with a linear increase in BC risk [Pnonlinear = 0.18; HRQ5 compared with Q1 (95% CI): 1.20 (1.08, 1.33); Ptrend < 0.01]. Associations were similar according to BC subtypes (Pheterogeneity > 0.05 for all).

CONCLUSIONS

Long-term adherence to healthful plant foods with some intake of unhealthy plant and animal foods may reduce BC risk with an optimal risk reduction in the moderate intake range. Adherence to an unhealthful plant-based diet may increase BC risk. These results emphasize the importance of the quality of plant foods for cancer prevention. This trial was registered at clinicaltrials.gov (NCT03285230).

Additive effects of obesity and vitamin D insufficiency on all-cause and cause-specific mortality

Obesity and vitamin D deficiency are both considered risk factors for mortality, but the potential additive effects of vitamin D status and obesity on mortality has not been well-studied. We aimed to examine the possible additive effects of obesity and vitamin D status on all-cause and cause-specific mortality. The data from the NHANES III (1988–1994) and NHANES 2001–2014 surveys were used, and multivariate Cox regression models were performed to assess the additive effects of vitamin D status and overweight/obesity/abdominal obesity on the all-cause, cardiovascular and cancer mortality, by stratifying Cox Hazard Ratios (HRs) across different categories of vitamin D status and body mass index (BMI) and waist circumference (WC) categories. The models were adjusted for age, race/ethnicity, gender, educational level, family income to poverty ratio, leisure-time physical activity, smoking, and drinking. Across all BMI/WC categories, there was an additive effect of the vitamin D both insufficiency and deficiency on all mortality rates, with deficiency having much stronger effect than insufficiency. Interestingly, the effect of vitamin D deficiency overcame the effect of obesity on all mortality rates. The highest HRs for overall and cardiovascular mortality were observed among vitamin D deficient obese/abdominally obese subjects, while for cancer mortality among vitamin D deficient normal weight/non-abdominally obese subjects. In stratified analyses, regarding all-cause mortality, there was an additive effect of the vitamin D both insufficiency and deficiency in all BMI/WC categories. Regarding cardiovascular mortality, there was an additive effect of vitamin D deficiency in all BMI/WC categories, but the additive effect of vitamin D insufficiency reached significance only in normal weight subjects. Regarding cancer mortality, the effect did not reach significance among obese subjects for vitamin D deficiency, while for insufficiency, significance was reached only among non-abdominally obese subjects. Interestingly, vitamin D surplus was associated with increased risk for cancer mortality in obese subjects, but there was an inadequate number of subjects in this category to make proper judgment. In conclusion, vitamin D insufficiency and deficiency gradually increase risk for mortality across all BMI/WC categories. In our analyses, vitamin D deficiency overcame the effect of obesity on mortality rates.

Nutritional Composition and Estimated Iron and Zinc Bioavailability of Meat Substitutes Available on the Swedish Market

Transition towards plant-based diets is advocated to reduce the climate footprint. Health implications of a diet composed of meat substitutes are currently unknown, and there are knowledge gaps in their nutritional composition and quality. Samples of available meat substitutes were bought in two convenience stores in the city of Gothenburg, Sweden, and were included in the study. Meat substitutes (n = 44) were analyzed for their contents of dietary fiber, fat, iron, zinc, phytate, salt, total phenolics and protein, as well as for their amino acid and fatty acid composition. Bioavailability of iron and zinc was estimated based on the phytate:mineral molar ratio. We found large variations in the nutritional composition of the analyzed meat substitutes. Amino acid profiles seemed to be affected by processing methods. Mycoprotein products were rich in zinc, with a median content of 6.7 mg/100 g, and had very low content of phytate, which suggests mycoprotein as a good source of zinc. Degradability of fungal cell walls might, however, pose as a potential aggravating factor. None of the products could be regarded as a good source of iron due to very high content of phytate (9 to 1151 mg/100 g) and/or low content of iron (0.4 to 4.7 mg/100 g). Phytate:iron molar ratios in products with iron contents >2.1 mg/100 g ranged from 2.5 to 45. Tempeh stood out as a protein source with large potential due to low phytate content (24 mg/100 g) and an iron content (2 mg/100 g) close to the level of a nutrition claim. Producers of the products analyzed in this study appear to use nutritional claims regarding iron that appear not in line with European regulations, since the iron is in a form not available by the body. Meat substitutes analyzed in this study do not contribute to absorbed iron in a relevant manner. Individuals following mainly plant-based diets have to meet their iron needs through other sources. Salt and saturated fat were high in certain products, while other products were more in line with nutritional recommendations. Further investigation of the nutritional and health effects of protein extraction and extrusion is needed. We conclude that nutritional knowledge needs to be implemented in product development of meat substitutes.

Time to transition from a negative nomenclature describing what NAFLD is not, to a novel, pathophysiology-based, umbrella classification of fatty liver disease (FLD)

Non-alcoholic fatty liver disease (NAFLD) is a definition of a prevalent condition that has been given a name describing what the disease is not, mainly due to gaps in the physiopathological understanding of NAFLD when the name was given to it. NAFLD still remains an unmet clinical need to a large extent due to the heterogenicity of the disease and the lack of a more accurate physiology-based classification. In essence, fatty liver disease (FLD) has a multifactorial etiology, including metabolic abnormalities, environmental influences, genetic disorders, and/or their overlap which makes it difficult to diagnose, design appropriate trials for it and treat this disease. Therefore, we propose herein that as our knowledge about this disease continues to grow exponentially, it is time to consider ending this unspecific, negative and broad classification of NAFLD, and turn it into a positive and targeted one describing what the disease is and not what it is not. Thus, we propose the novel FLD "Mantzoros classification". This innovative classification proposes to classify the heterogeneous causes of FLD under one umbrella and eventually lead to a better nomenclature and classification system reflecting pathophysiology. This in turn could lead to both better clinical trials and more personalized care. An additional aim is to generate a dialogue among the experts in this field to eventually reach the right nomenclature for an appropriate disease classification that would facilitate our understanding, approach, diagnosis, and management of this epidemic of FLD. Overall, a novel classification, based on phenotypic manifestations, leading risk factors and probable causes of FLD, could help our understanding and clinically would be accurately defining and differentiating the disease, leading to a more accurate design and execution of clinical trials. This would in turn lead to tangible benefits for all patients suffering from FLD through targeted and more effective personalized treatments.