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

The association between plant-based diet indices and the risk of breast cancer: a case-control study

BACKGROUND

Previous studies examining the relationship between plant-based diets and breast cancer (BrC) have provided conflicting evidence. To address these inconsistencies, we aimed to evaluate the association between the plant-based diet index (PDI), healthful PDI (hPDI), and unhealthy PDI (uPDI) with the odds of BrC in Iranian women.

METHODS

The current case-control research was performed on 133 Iranian women with BrC and 265 controls. The study subjects were selected from hospitals in Tehran. PDI, hPDI, and uPDI were categorized into eighteen food groups based on nutrient composition similarity. The relationship between PDIs and BrC was assessed using logistic regression.

RESULTS

After adjusting for confounding factors, the chance of developing BrC was lower in the highest tertile of hPDI compared to the lowest tertile (odds ratio (OR) = 0.495; 95% confidence interval (CI): 0.274-0.891; P = 0.019). In addition, postmenopausal women in the second and last tertiles of hPDI had lower odds of BrC than those in the first tertile (T) (T2: OR = 0.342; 95% CI: 0.141-0.828; P = 0.017- T3: OR = 0.262; 95% CI: 0.107-0.639; P = 0.003) in the adjusted model. Furthermore, in premenopausal women in the highest tertile of uPDI, the odds of BrC were increased compared to the lowest tertile (OR = 2.546; 95% CI: 1.051-6.167; P = 0.038) in the adjusted model.

CONCLUSIONS

Adherence to a healthy plant-based dietary pattern, including vegetables, fruits, whole grains, nuts, and legumes, seems to be beneficial for BrC prevention, particularly in postmenopausal women. Future prospective cohort studies that consider menopausal status and the type of BrC are needed to support these findings.

Diet, fruit and vegetables and One Health: benefits for health, environment, society and the consumer-proceedings of the 9th edition of EGEA conference

PURPOSE

To present the outcomes of the EGEA Conference on the state of knowledge regarding the contribution of diets rich in fruit and vegetables (FV) to human and planetary health, commonly included in the One Health concept.

METHODS

The 9th edition of EGEA Conference (20-22 September 2023, Barcelona) provided a transversal and multidisciplinary perspective on the contribution of FV to One Health, in particular to the health of individuals, society and the planet. Nearly 150 international scientists and stakeholders discussed the current state of knowledge. These proceedings are based both on a literature review and the scientific studies presented by the speakers.

RESULTS

Scientific evidence confirms the role of FV in preventing cardiovascular diseases and type 2 diabetes; more evidence is needed on the effects and mechanisms of FV in cancer prevention. FV production and consumption helps ensure territorial cohesion and provides a denser, nutrient-rich diet with less environmental impact (except water use) than other food groups, but use of synthetic pesticides in FV production remains a challenge that could be addressed with agro-ecological solutions. Various factors influence consumer choice and behaviour towards FV consumption across the lifespan, with specific periods being more conducive to change. New research is emerging on the role of FV consumption in regulating gut microbiota and on both mental and brain health; the potential role of FV production and supply in tackling biodiversity loss and climate change; and better monitoring of FV consumption.

CONCLUSION

Sufficient evidence confirms the contribution of diet rich in FV to One Health, with some emerging research on this topic. Concerted actions are required towards an increased consumption of FV and a more diversified and environmentally neutral FV production.

Role of a Whole Plant Foods Diet in Breast Cancer Prevention and Survival

Breast cancer (BC) is one of the leading causes of death and morbidity among women worldwide. Epidemiologic evidence shows that the risk of BC and other chronic diseases decreases as the proportion of whole plant foods increases, while the proportion of animal foods (fish, meat, poultry, eggs, seafood, and dairy products) and non-whole plant foods (e.g., refined grains, added sugars, French fries) in the diet decreases. Whole plant foods include fruits, vegetables, roots, tubers, whole grains, legumes, nuts, and seeds from which no edible part has been removed and to which no non-whole food been added. A whole plant foods diet lowers insulin resistance, inflammation, excess body fat, cholesterol, and insulin-like growth factor 1 and sex hormone bioavailability; it also increases estrogen excretion, induces favorable changes in the gut microbiota, and may also favorably affect mammary microbiota composition and decrease the risk of early menarche, all contributing to reduced BC incidence, recurrence, and mortality. This review explores the connection between a whole plant foods diet and BC risk and mortality as well as the potential mechanisms involved. Additionally, this diet is compared with other dietary approaches recommended for BC. A whole plant foods diet seems the optimal dietary pattern for BC and overall disease prevention as it exclusively consists of whole plant foods which, based on existing evidence, lead to the best health outcomes.

An unbiased, sustainable, evidence-informed Universal Food Guide: a timely template for national food guides

BACKGROUND

Although national food guides are designed, ostensibly, to translate scientific evidence with respect to food, dietary patterns, and health, their development has increasingly become a corporate/political process as well as scientific one; often with corporate/political influences overriding science. Our aim was to construct an unbiased, sustainable, evidence-informed Universal Food Guide to serve as a template for countries to develop their unique guides, thereby, provide a valid resource for health professionals, health authorities, and the public.

METHODS

To address our aim, we conducted an integrative review of multiple evidence-informed sources (e.g., established databases, evidence syntheses, scholarly treatises, and policy documents) related to four areas: 1. Food guides' utility and conflicts of interest; 2. The evidence-based healthiest diet; 3. Constituents of the Universal Food Guide template; and 4. Implications for population health; regulation/governance; environment/climate/planetary health; and ethics.

RESULTS

The eating pattern that is healthiest for humans (i.e., most natural, and associated with maximal health across the life cycle; reduced non-communicable disease (NCD) risk; and minimal end-of-life illness) is whole food, low fat, plant-based, especially vegan, with the absence of ultra-processed food. Disparities in national food guide recommendations can be explained by factors other than science, specifically, corporate/political interests reflected in heavily government-subsidized, animal-sourced products; and trends toward dominance of daily consumption of processed/ultra-processed foods. Both trends have well-documented adverse consequences, i.e., NCDs and endangered environmental/planetary health. Commitment to an evidence-informed plant-based eating pattern, particularly vegan, will reduce risks/manifestations of NCDs; inform healthy food and nutrition policy regulation/governance; support sustainable environment/climate and planetary health; and is ethical with respect to 'best' evidence-based practice, and human and animal welfare.

CONCLUSION

The Universal Food Guide that serves as a template for national food guides is both urgent and timely given the well-documented health-harming influences that corporate stakeholders/politicians and advisory committees with conflicts of interest, exert on national food guides. Such influence contributes to the largely-preventable NCDs and environmental issues. Policy makers, health professionals, and the public need unbiased, scientific evidence as informed by the Universal Food Guide, to inform their recommendations and choices.

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.

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.

Dietary Patterns Associated with Breast Cancer in the Middle East: A Scoping Review

Breast cancer (BC) is the most predominant malignancy in Arab women in the Middle East, and yearly increases in occurrence by 37.5 and mortality rates by 15.2 for every 100,000 in 2019. This review explores the gap in research investigating the role of dietary patterns and BC in Middle Eastern countries. Furthermore, we analyze the evidence connecting these patterns to BC prevalence in the region, discussing implications for public health and preventive strategies. PubMed, ProQuest, and Cochrane databases were searched up to November 2023. Articles published in English from 2000 to 2023 were identified. Our search included dietary patterns (DP), their association with BC and specific to Middle Eastern Regions. The majority of existing research is concentrated in Iran, with limited illustration from Saudi Arabia, Turkey, and Jordan, and a notable absence of studies from other Middle Eastern countries. We found that dietary intervention is closely related to the occurrence, development, and prognosis of BC. Most DPs such as the Dietary Approaches to Stop Hypertension, Mediterranean, Plant-based and Paleolithic diets are identified to decrease the probability of BC by being rich sources of fiber, healthy fats, and vitamins and minerals. However, there are few DPs that increase the risk of BC, because of the existence of foods such as unhealthy fats, low fiber, sugars, and fried foods in those patterns which contribute to increasing the risk factors associated with BC. This review highlights the intricate connection between DPs and the risk of BC in the Middle East, revealing potential protective effects and heightened risks linked to specific dietary elements.

Pro-Vegetarian Food Patterns and Cancer Risk among Italians from the Moli-Sani Study Cohort

Besides the Mediterranean diet, there is a paucity of studies examining plant-based diets in relation to cancer outcomes in Mediterranean populations. We analyzed 22,081 apparently cancer-free participants (mean age 55 ± 12 year) from the Moli-sani study (enrollment period 2005-2010; Italy). A general pro-vegetarian food pattern was computed by assigning positive or negative scores to plant- or animal-derived foods, respectively from a 188-item FFQ. A priori healthful or unhealthful pro-vegetarian food patterns distinguished between healthy plant foods (e.g., fruits, vegetables) and less-healthy plant foods (e.g., fruit juices, refined grains). Cancer incidence was defined as the earliest diagnosis of cancer from hospital discharge records over a median follow-up of 12.9 years. In multivariable-adjusted analyses, a general pro-vegetarian food pattern was associated with a lower rate of cancer incidence (HR = 0.85; 95%CI 0.75-0.97 for Q5 vs. Q1); no association was observed between the healthful or unhealthful pro-vegetarian food patterns and overall cancer incidence. A healthful pro-vegetarian pattern, however, was inversely associated with digestive cancer (HR = 0.76; 95%CI 0.58-0.99 for Q5 vs. Q1), while the unhealthful pro-vegetarian pattern was directly linked to respiratory cancer (HR = 1.68; 95%CI 1.06-2.68 for Q5 vs. Q1). Our findings in a Mediterranean population support the hypothesis that some, but not all pro-vegetarian diets, might prevent some cancers.