Association between a pro plant-based dietary score and cancer risk in the prospective NutriNet-santé cohort

Pro-vegetarian dietary patterns and mortality by all-cause and specific causes in an older Mediterranean population

PURPOSE

Pro-vegetarian (PVG) dietary patterns have shown health benefits, although the evidence concerning their association with mortality is scarce, particularly in older populations. We investigated the effect of three defined PVG patterns on all-cause, cardiovascular disease (CVD) and cancer mortality risk in an older Mediterranean population.

METHODS

We analysed baseline data from 597 adults aged 65 and older who participated in a population-based cross-sectional study, and mortality during a 12-year period. We used a validated food frequency questionnaire to estimate the adherence in tertiles to three evidence-based PVG dietary patterns: a general PVG pattern (gPVG) and two specific variations (healthful -hPVG, and unhealthful -uPVG). The gPVG pattern incorporated data from 12 food groups, consisting of 7 plant-based and 5 animal-based. The hPVG and uPVG versions included information from 18 food groups (4 food groups added and the splitting of 2 food groups). We used Cox regression to estimate hazard ratios (HR) and 95% confidence intervals (CI) adjusting for relevant covariates.

RESULTS

After the 12-years follow-up period, moderate adherence to hPVG pattern was associated with lower all-cause and CVD mortality whereas greater adherence to uPVG pattern was associated with higher all-cause and CVD mortality. Compared with those in the lowest tertile, participants in the second tertile of adherence to the hPVG pattern showed a significant lower risk of all-cause mortality (HR = 0.59; 95%CI: 0.43, 0.82) and CVD mortality (HR = 0.47; 0.28, 0.78). Participants in the highest tertile of adherence to the uPVG showed an increased mortality risk of all-cause (HR = 1.53; 1.07, 2.19) and CVD (HR = 2.10; 1.19, 3.70). No significant associations were found between adherence to any of the PVG dietary patterns and cancer mortality.

CONCLUSION

Moderate adherence to a healthy PVG pattern reduced the long-term mortality risk for all-cause and CVD in an older Mediterranean population, while higher adherence to an unhealthy PVG pattern increased the risk of all-cause and CVD mortality.

Pro-vegetarian dietary pattern and risk of breast cancer: a case-control study

BACKGROUND

There are a few conflicting results from studies assessing the association between plant-based diets, particularly pro-vegetarian dietary pattern (PDP), and breast cancer (BC) incidence. Therefore, this study aimed to investigate the association between PDP and BC odds in the Iranian population.

METHODS

This case-control study was conducted on 134 women with BC and 265 without cancer (control). Participants were selected from two referral hospitals in Tehran, Iran. Also, a validated food frequency questionnaire was used to collect food information. Logistic regression was used to assess the association between PDP and BC and the association between PDP and BC by menopausal status.

RESULTS

It was observed that in two models of logistic regression, the chance of BC was lower in the second and last tertile (T) than in the first tertile of PDP (model 1-T2: odds ratio (OR) = 0.39; 95% confidence interval (CI): 0.23-0.67; P = 0.001, and T3: OR = 0.43; 95% CI: 0.26-0.73; P = 0.002-model 2: T2: OR = 0.42; 95% CI: 0.24-0.74; P = 0.003, and T3: OR = 0.49; 95% CI: 0.27-0.88; P = 0.017). Also, according to menopausal status, the odds of developing BC in post-menopausal women in the second and last tertile of PDP was significantly lower than the first tertile in both logistic regression models.

CONCLUSIONS

The findings revealed that Iranian women who followed PDP had a lower chance of developing BC. Also, we found that a diet high in plant-based foods and low in animal products is beneficial for reducing BC odds, particularly for post-menopausal women.

Prognostic features of the tumor microenvironment in high-grade serous ovarian cancer and dietary immunomodulation

High-grade serous ovarian cancer (HGSOC) is a particularly lethal malignancy that is prognostically influenced by the immune profile of the tumor microenvironment (TME). TME immune profiles have been sub-categorized according to features associated with both survival outcomes as well as response to systemic therapies. Five suggested immune phenotypes have been described and correlated with overall survival outcomes. Phenotypes associated with shorter overall survival rates appear to have prominent immunosuppressive features within their TME. The opportunity to triage patients according to their prognostic TME profile might allow selection of individual patients with poor prognostic features who could most benefit from innovative immunomodulatory treatment strategies. Two potential strategies to indirectly manipulate the TME (and oncologic outcomes) are alteration of the gut microbiome composition and alteration of TME metabolism through dietary interventions. Experimental dietary modifications in humans designed for influencing cancer outcomes are only beginning to be studied in a prospective fashion. Herein we summarize prognostic TME features in HGSOC and potential opportunities for immunomodulation via dietary and gut microbial interventions.

Healthy and Unhealthy Plant-Based Diets and Glioma in the Chinese Population

Plant-based diets have been suggested to help prevent various chronic diseases, including cancer. However, there are few reports on central nervous system tumors, and data on dose-response relationships are lacking. This individual-matched case-control study included 506 cases and 506 controls. The overall plant-based diet index (PDI), the healthy plant-based diet index (hPDI), and the unhealthy plant-based diet index (uPDI) were calculated using dietary information collected through a food frequency questionnaire, with higher scores indicating better adherence. We analyzed the relationship of plant-based diets with glioma. After adequate adjustment for confounders, PDI was associated with a reduced glioma risk (OR = 0.42, 95% CI: 0.24-0.72). Conversely, uPDI was associated with an elevated glioma risk (OR = 8.04, 95% CI: 4.15-15.60). However, hPDI was not significantly associated with glioma risk (OR = 0.83, 95% CI: 0.48-1.45). For subgroups, PDI was not significant in analyzing young age, BMI, or any pathological subtypes. The restricted cubic spline function showed a significant dose-response relationship between PDI (p-nonlinearity< 0.0001) and uPDI (p-nonlinearity= 0.0711) and glioma. Further analysis found that refined grains had the greatest effect on gliomas in the less healthy plant-based food group. Therefore, following a plant-based diet was linked to a lower risk of glioma, especially when consuming fewer unhealthy plant-based foods.

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.

Mechanisms underlying the effects, and clinical applications, of oral microbiota in lung cancer: current challenges and prospects

The oral cavity contains a site-specific microbiota that interacts with host cells to regulate many physiological processes in the human body. Emerging evidence has suggested that changes in the oral microbiota can increase the risk of lung cancer (LC), and the oral microbiota is also altered in patients with LC. Human and animal studies have shown that oral microecological disorders and/or specific oral bacteria may play an active role in the occurrence and development of LC through direct and/or indirect mechanisms. These studies support the potential of oral microbiota in the clinical treatment of LC. Oral microbiota may therefore be used in the prevention and treatment of LC and to improve the side effects of anticancer therapy by regulating the balance of the oral microbiome. Specific oral microbiota in LC may also be used as screening or predictive biomarkers. This review summarizes the main findings in research on oral microbiome-related LC and discusses current challenges and future research directions.

Dietary Patterns and Risk of Lung Cancer: A Systematic Review and Meta-Analyses of Observational Studies

PURPOSE OF REVIEW

Previous literature reviews summarized the associations between individual foods or food groups and lung cancer risk, but the relationship between dietary patterns and lung cancer risk has received less attention. We conducted a systematic review and meta-analyses of observational studies on the associations between dietary patterns and lung cancer risk.

RECENT FINDINGS

PubMed, Embase, and Web of Science were systematically searched from inception to February 2023. Random-effects models were used to pool relative risks (RR) on associations with at least two studies. Twelve studies reported on data-driven dietary patterns, and 17 studies reported on a priori dietary patterns. A prudent dietary pattern (high in vegetables, fruit, fish, and white meat) tended to be associated with a lower risk of lung cancer (RR = 0.81, 95% confidence interval [CI] = 0.66-1.01, n = 5). In contrast, Western dietary patterns, characterized by higher intakes of refined grains and red and processed meat, were significantly positively associated with lung cancer (RR = 1.32, 95% CI = 1.08-1.60, n = 6). Healthy dietary scores were consistently associated with a lower risk of lung cancer (Healthy Eating Index [HEI]: RR = 0.87, 95% CI = 0.80-0.95, n = 4; Alternate HEI: RR = 0.88, 95% CI = 0.81-0.95, n = 4; Dietary Approaches to Stop Hypertension: RR = 0.87, 95% CI = 0.77-0.98, n = 4; Mediterranean diet: RR = 0.87, 95% CI = 0.81-0.93, n = 10) while the dietary inflammatory index was associated with a higher risk of lung cancer (RR = 1.14, 95% CI = 1.07-1.22, n = 6). Our systematic review indicates dietary patterns characterized by a higher intake of vegetables and fruits, a lower intake of animal products, and anti-inflammation may be associated with a reduced risk of lung cancer.

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).

Plant-Based Diets and the Incidence of Asthma Symptoms among Elderly Women, and the Mediating Role of Body Mass Index

We aimed to test the hypothesis that adherence to a healthful plant-based diet (hPDI) is associated with a subsequent decrease in the incidence of asthma symptoms, with an opposite association with adherence to an unhealthful plant-based diet (uPDI). In addition, we evaluated a potential mediating role of body mass index (BMI) and the modifying effect of smoking. Among 5700 elderly women from the French Asthma-E3N study with dietary data in 1993 and 2005, we assessed the incidence of asthma symptoms in 2018 among women with no asthma symptoms in 2011. BMI was evaluated in 2008. Mediation analyses in the counterfactual framework were used to disentangle total, direct, and indirect effects mediated by BMI. We found that both healthful and unhealthful plant-based diets were associated with a lower incidence of asthma symptoms over time, mediated by BMI (OR (95%CI) for the indirect effect: 0.94 (0.89-1.00) for hPDI and 0.92 (0.70-1.00) for uPDI)). Associations with both healthful and unhealthful PDIs were mediated by changes in BMI by 33% and 89%, respectively. Plant-based diets (healthful and unhealthful) were associated with subsequently reduced incidences of asthma symptoms over time, partly or almost totally mediated by BMI according to their nutritional quality.

Adherence to Pro-Vegetarian Food Patterns and Risk of Oesophagus, Stomach, and Pancreas Cancers: A Multi Case-Control Study (The PANESOES Study)

We aimed to evaluate the association between three previously defined pro-vegetarian (PVG) food patterns and the cancers of the oesophagus, stomach, and pancreas in a multi case-control study. We analyzed data from a multi-case hospital-based study carried out in two Mediterranean provinces in Spain. A total of 1233 participants were included in the analyses: 778 incident cancer cases, histologically confirmed (199 oesophagus, 414 stomach, and 165 pancreas) and 455 controls. A dietary assessment was performed using a validated food frequency questionnaire (FFQ). Three PVG food patterns (general, healthful, and unhealthful) were estimated using 12 food groups for the general PVG (gPVG), scoring positive plant-based foods and negative animal-based foods, and 18 food groups, for the healthful (hPVG) and unhealthful (uPVG) food patterns. Multinomial logistic regression was used to estimate relative risk ratios (RRR) and confidence intervals (95% CI) for quintiles of adherence to PVG patterns and as a continuous variable. The RRR (95% CI) for the highest vs. the lowest quintile of gPVG were, RRR = 0.37 (0.32, 0.42) for the oesophagus, RRR = 0.34 (0.27, 0.43) for the stomach, and RRR = 0.43 (0.35, 0.52) for pancreas cancer. For the hPVG, the RRR were RRR = 0.72 (0.58, 0.90) for the oesophagus, RRR = 0.42 (0.34, 0.52) for the stomach, and RRR = 0.74 (0.59, 0.92) for pancreas cancer. The uPVG was associated with a higher risk of stomach cancer RRR = 1.76 (1.42, 2.18). Higher adherence to gPVG and hPVG food patterns is associated with a lower risk of oesophageal, stomach, and pancreas cancers, while a higher adherence to a uPVG food pattern is associated with a higher risk of stomach cancer.

Association of plant-based dietary patterns with the risk of colorectal cancer: a large-scale case-control study

Plant-based diets are associated with a lower risk of colorectal cancer, but the risk might differ by the quality of plant-based diets. This study aimed to investigate the association between different types of plant-based dietary patterns and colorectal cancer risk in the Chinese population. We conducted a case-control study with 2799 eligible colorectal cancer cases and 2799 sex- and age-matched controls in Guangzhou, China. A validated food frequency questionnaire was used to collect dietary data, from which we derived plant-based diet indices, including the plant-based diet index (PDI), the healthy PDI (hPDI), and the unhealthy PDI (uPDI). The PDI, hPDI, and uPDI assess the adherence to overall, healthy, and unhealthy plant-based dietary patterns, respectively. The odds ratios (ORs) and 95% confidence intervals (CIs) for colorectal cancer risk were estimated using unconditional logistic regression models. Higher adherence to the PDI, particularly the hPDI, was associated with a lower risk of colorectal cancer, whereas greater adherence to the uPDI was associated with a higher risk of colorectal cancer. Compared with the lowest quintile, the adjusted ORs in the highest quintile were 0.79 (95% CI: 0.66-0.95) for the PDI, 0.45 (95% CI: 0.38-0.55) for the hPDI, and 1.45 (95% CI: 1.18-1.78) for the hPDI, respectively. In stratified analysis, the inverse association between the PDI and colorectal cancer risk was not observed in women, and the positive association between the uPDI and colorectal cancer risk was not observed in men. In conclusion, these results support recommendations that shifting to a healthy plant-based dietary pattern is important for the prevention of colorectal cancer, particularly in the Chinese population that habitually consumes plant foods.

The Impact of a Plant-Based Diet on Indices of Cardiovascular Health in African Americans: A Cross-Sectional Study

African American (AA) individuals are disproportionately affected by cardiovascular diseases. Plant-based diets (PBD) may be cardioprotective in part through their high antioxidant capacity and low inflammatory load. We tested the hypothesis that AA individuals adhering to a 100% PBD would have better vascular health than AA individuals following a typical American diet (TAD). Eighteen AA individuals participated; 9 (24±4 years; 6 females) were following a PBD for 2.4±0.8 years and 9 (21±2 years; 5 females) were following a TAD. Blood lipids and C-reactive protein (CRP) were assessed. Peripheral and central blood pressure (BP) were measured, and vascular function tests included cerebrovascular reactivity to hypercapnia, brachial artery flow-mediated dilation & reactive hyperemia, and local heating-induced cutaneous hyperemia. Total (TC) and low-density lipoprotein (LDL-C) serum cholesterol were lower (TC: 142±30 vs. 174±36 mg/dl; LDL-C: 76±17 vs. 106±33 mg/dl; p<0.05 and d>0.80 for both) and serum CRP tended to be lower (0.38±0.18 mg/l vs. 0.96±0.89 mg/l; p=0.05, d=0.91) in the PBD cohort. Brachial (b) and central (c) mean arterial BP (MAP) were lower in the PBD cohort (bMAP: 86±5 vs. 91±7 mmHg; cMAP: 81±5 vs. 87±7 mmHg; p<0.05 and d>0.80 for both). All indices of vascular function were similar between groups (p>0.05 for all). A PBD was associated with more optimal blood lipid concentrations and decreased peripheral and central BP in AA individuals, but this association was not present in the various indices of vascular function. Registered at ClinicalTrials.gov: NCT05344287.

Plant-Based Diets and Cancer Risk: What is the Evidence?

PURPOSE OF REVIEW

The purpose of this review is to summarize the recent (past 5 years) available evidence regarding the association between plant-based diets on cancer risk from clinical trials and observational studies. Biological mechanisms and gaps in the current literature will also be discussed.

RECENT FINDINGS

There is a lack of intervention studies but there are abundant observational studies assessing the association between plant-based diets and cancer risk, including multiple longitudinal cohort studies and similar data from case-control studies that demonstrate a decreased overall cancer risk with plant-based diets. Case-control studies support a decreased risk of colorectal and breast cancers with plant-based diets, but results for specific cancers remain inconsistent in cohort studies. Current evidence from observational studies indicates an inverse association between plant-based diets and overall cancer risk. Future research should include intervention studies, address inconsistencies in dietary assessment methods and provide greater detail on underrepresented groups.

Perspective: Identifying Ultra-Processed Plant-Based Milk Alternatives in the USDA Branded Food Products Database

This study explored the characteristics of plant-based beverages (PBBs) that are marketed as "milks" in the United States. First, machine searches of product names and ingredients in the USDA Branded Food Products Database (BFPDB) yielded 641 nondairy PBBs that included almond, soy, coconut, cashew, other tree nut, flax/hemp, pea, and quinoa and rice "milks." The products varied in energy density and the majority of PBBs contained added salt (69%) and added sugar (53%). Scores on nutrient density metrics [Nutri-Score, Choices, and the Nutrient Rich Food index 7.3 (NRF7.3)] were higher for almond and pea products and lower for coconut PBBs, which contained saturated fat. Ingredient lists were searched further for added flavors, stabilizers, or preservatives said to be characteristic of the NOVA food classification system's ultra-processed group. Most PBBs (90.1%) and 95% of almond milks met the NOVA criteria for ultra-processed foods, because they were created from food components and contained multiple substances not used in normal cooking. Replacing milk and dairy products with plant-based alternatives will necessarily involve the use of ultra-processed foods.

Adherence to plant-based dietary patterns in relation to glioma: a case-control study

Available evidence suggests a favorable association between adherence to a plant-based diet and disease prevention, but data on the link between such dietary intakes and cancer are scarce. We examined the association between the overall plant-based diet (PDI), healthy plant-based diet (hPDI), and unhealthy plant-based diet (uPDI) and risk of glioma. This case–control study was conducted on 128 newly diagnosed glioma patients, and 256 hospital-based controls. Cases were diagnosed by pathological test and controls were selected from hospitalized people in orthopedic and surgical wards. Dietary intakes were assessed using a validated Block-format 123-items food frequency questionnaire. Scores of plant-based dietary patterns were calculated using the method suggested by Satija et al. After controlling for potential confounders, individuals with higher scores of PDI (OR: 0.54, 95% CI: 0.32–0.91, P-trend < 0.001) and hPDI (OR: 0.32, 95% CI: 0.18–0.57, P-trend < 0.001) had significantly lower odds of glioma compared with those with the lowest scores. This association did not change in the fully adjusted model; such that subjects in the highest tertile of PDI and hPDI were 69% and 71% less likely to have glioma compared with those in the lowest tertile. In contrast, higher scores of uPDI was significantly associated with a greater odds of glioma (OR: 2.85, 95% CI: 1.26–6.47, P-trend = 0.02). Adherence to PDI and hPDI was associated with a lower odds of glioma, while greater adherence to uPDI was directly associated with the likelihood of glioma. Further prospective cohort studies are needed to examine our findings.

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.

Healthful and Unhealthful Plant-Based Diets and Risk of Breast Cancer in U.S. Women: Results from the Nurses' Health Studies

BACKGROUND

Plant-based diets have been associated with lower risk of various diseases, including type 2 diabetes, cardiovascular disease, and other cardiometabolic risk factors. However, the association between plant-based diet quality and breast cancer remains unclear.

METHODS

We prospectively followed 76,690 women from the Nurses' Health Study (NHS, 1984-2016) and 93,295 women from the NHSII (1991-2017). Adherence to an overall plant-based diet index (PDI), a healthful PDI (hPDI), and an unhealthful PDI (uPDI) was assessed using previously developed indices. Cox proportional hazards models were used to estimate HR and 95% confidence intervals (CI) for incident invasive breast cancer.

RESULTS

Over 4,841,083 person-years of follow-up, we documented 12,482 incident invasive breast cancer cases. Women with greater adherence to PDI and hPDI were at modestly lower risk of breast cancer [(HR_{Q5 vs. Q1}, 0.89; 95% CI, 0.84-0.95); (HR_{Q5 vs. Q1}, 0.89; 95% CI, 0.83-0.94)]. We observed significant heterogeneity by estrogen receptor (ER) status, with the strongest inverse association between hPDI and breast cancer observed with ER-negative tumors [HR_{Q5 vs. Q1}, 0.77; 95% CI, 0.65-0.90; P _trend < 0.01]. We also found an inverse association between extreme quintiles of healthy plant foods and ER-negative breast cancer [HR, 0.74; 95% CI, 0.61-0.88; P _trend < 0.01].

CONCLUSIONS

This study provides evidence that adherence to a healthful plant-based diet may reduce the risk of breast cancer, especially those that are more likely to be aggressive tumors.

IMPACT

This is the first prospective study investigating the relation between healthful and unhealthful plant-based dietary indices and risk of total and subtype-specific breast cancer.

The association between plant-based dietary patterns and risk of breast cancer: a case-control study

Limited data are available, linking the plant-based diets to breast cancer (BC). We examined the association of overall plant-based diet index (PDI), hypothesized healthful (hPDI) and unhealthful versions of a plant-based diet index (uPDI) with BC in Iranian women. This population-based case–control study included 350 cases with newly diagnosed BC and 700 age-matched apparently healthy controls. We collected dietary data using a validated, Willett-format semi-quantitative food frequency questionnaire. Using these data, we generated a PDI by dedicating positive scores to plant foods, and reverse scores to animal foods, hPDI by assigning positive scores to healthy plant foods and reverse scores to less healthy plant foods and animal foods, and finally uPDI in which positive scores were assigned to less healthy plant foods and reverse scores to healthy plant foods and animal foods. After controlling for potential confounders, individuals in the highest quartile of PDI had 67% lower odds of BC than those in the lowest quartile (OR 0.33; 95% CI 0.22–0.50). Individuals with the greatest adherence to hPDI were 36% less likely to have BC than those with the lowest adherence, in the fully adjusted model (OR 0.64; 95% CI 0.43–0.94). In terms of uPDI, women in the top quartile had a 2.23 times greater chance of BC than those in the bottom quartile (OR 2.23; 95% CI 1.48–3.36). Greater adherence to PDI and hPDI was inversely associated with the risk of BC, whereas uPDI was associated with an increased risk.

Healthful and unhealthful provegetarian food patterns and the incidence of breast cancer: Results from a Mediterranean cohort

OBJECTIVES

Provegetarian diets, also known as predominantly plant-based (but not vegetarian or vegan) or plant-forward diets, have been associated with health benefits. However, a distinction is needed between high- and low-quality provegetarian dietary patterns (PVGs). We sought to examine potential associations between PVG indices and breast cancer (BC) incidence.

METHODS

We assessed 10 812 women in the Seguimiento Universidad de Navarra cohort. We calculated an overall PVG pattern from a validated semi-quantitative food-frequency questionnaire as proposed by Martínez-Gonzalez et al, assigning positive scores (based on quintiles) to plant foods and reversing the quintile scores for animal foods. Participants were categorized according to tertiles of the overall score. We also calculated a healthful PVG (hPVG) and unhealthful PVG (uPVG) as proposed by Satija et al. RESULTS: After a median of 11.5 years of follow-up, 101 incident BC cases, confirmed by medical records, were observed. A significant inverse association with BC (comparing tertile 2 vs. tertile 1, HR= 0.55; 95% confidence interval, 0.32-0.95) was identified for a modest overall PVG, but not for hPVG and uPVG separately. Nevertheless, the highest tertile was not associated with BC.

CONCLUSIONS

In this large prospective cohort study, a moderate adherence to a PVG might decrease the risk of BC. Further studies should replicate and expand these results to other racial, ethnic, and socioeconomic groups.

Plant-Protein Diversity Is Critical to Ensuring the Nutritional Adequacy of Diets When Replacing Animal With Plant Protein: Observed and Modeled Diets of French Adults (INCA3)

BACKGROUND

There is a current trend in Western countries toward increasing the intake of plant protein. A higher plant-protein intake has been associated with nutritional and health benefits, but these may depend on the pattern of plant-protein sources.

OBJECTIVE

We hypothesized that the diversity of plant foods could be important to nutrient adequacy when increasing plant-protein intake in the diet.

METHODS

Using data on 1341 adults (aged 18-64 y) from a representative French national dietary survey conducted in 2014-2015 (the third Individual and National Study on Food Consumption Survey-INCA3), we studied the links between plant-protein intake, dietary diversity (using various dimensions), and nutrient adequacy [assessed using the PANDiet (Probability of Adequate Nutrient Intake) scoring system, comprising adequacy (AS) and moderation (MS) subscores]. We simulated substituting plant-protein foods for animal-protein foods using different models of plant-protein diversity.

RESULTS

We found that overall diet quality was weakly associated with total and protein diversity and more strongly with plant-protein diversity. Plant-protein intake was inversely associated with animal-protein intake, and positively with the PANDiet and MS, but not with the AS. Plant-protein intake displayed little diversity, mostly taking the form of grains (61% of plant-protein intake), and this diversity was even less marked under a higher plant-protein intake. Finally, modeled substitutions showed that reducing animal-protein intake increased the MS (by 32%) in a similar manner whichever plant protein was used for substitution, whereas it decreased the AS (by 20%) unless using a highly diversified plant-protein mix. These simulated improvements in overall adequacy included marked decreases in adequacy regarding certain nutrients that are typically of animal origin.

CONCLUSIONS

We conclude that in French adults the current pattern of plant-protein intake is hindering the nutritional benefits of a transition toward more plant protein, indicating that the consumption of plant-protein-based foods other than refined grains should be encouraged.

Association of Dietary Fiber and Yogurt Consumption With Lung Cancer Risk: A Pooled Analysis

Importance

Dietary fiber (the main source of prebiotics) and yogurt (a probiotic food) confer various health benefits via modulating the gut microbiota and metabolic pathways. However, their associations with lung cancer risk have not been well investigated.

Objective

To evaluate the individual and joint associations of dietary fiber and yogurt consumption with lung cancer risk and to assess the potential effect modification of the associations by lifestyle and other dietary factors.

Design, Setting, and Participants

This pooled analysis included 10 prospective cohorts involving 1 445 850 adults from studies that were conducted in the United States, Europe, and Asia. Data analyses were performed between November 2017 and February 2019. Using harmonized individual participant data, hazard ratios and 95% confidence intervals for lung cancer risk associated with dietary fiber and yogurt intakes were estimated for each cohort by Cox regression and pooled using random-effects meta-analysis. Participants who had a history of cancer at enrollment or developed any cancer, died, or were lost to follow-up within 2 years after enrollment were excluded.

Exposures

Dietary fiber intake and yogurt consumption measured by validated instruments.

Main Outcomes and Measures

Incident lung cancer, subclassified by histologic type (eg, adenocarcinoma, squamous cell carcinoma, and small cell carcinoma).

Results

The analytic sample included 627 988 men, with a mean (SD) age of 57.9 (9.0) years, and 817 862 women, with a mean (SD) age of 54.8 (9.7) years. During a median follow-up of 8.6 years, 18 822 incident lung cancer cases were documented. Both fiber and yogurt intakes were inversely associated with lung cancer risk after adjustment for status and pack-years of smoking and other lung cancer risk factors: hazard ratio, 0.83 (95% CI, 0.76-0.91) for the highest vs lowest quintile of fiber intake; and hazard ratio, 0.81 (95% CI, 0.76-0.87) for high vs no yogurt consumption. The fiber or yogurt associations with lung cancer were significant in never smokers and were consistently observed across sex, race/ethnicity, and tumor histologic type. When considered jointly, high yogurt consumption with the highest quintile of fiber intake showed more than 30% reduced risk of lung cancer than nonyogurt consumption with the lowest quintile of fiber intake (hazard ratio, 0.67 [95% CI, 0.61-0.73] in total study populations; hazard ratio, 0.69 [95% CI, 0.54-0.89] in never smokers), suggesting potential synergism.

Conclusions and Relevance

Dietary fiber and yogurt consumption was associated with reduced risk of lung cancer after adjusting for known risk factors and among never smokers. Our findings suggest a potential protective role of prebiotics and probiotics against lung carcinogenesis.

Temporal trends in food group availability and cancer incidence in Africa: an ecological analysis

OBJECTIVE

We evaluated the relationship between food availability, as the only dietary exposure data available across Africa, and age-standardised cancer incidence rates (ASR) in eighteen countries.

DESIGN

Ecological study.

SETTING

Availability of food groups and dietary energy was considered for five hypothetical time points: years of collection of ASR (T0) and 5, 10, 15 and 20 preceding years (T-5, T-10, T-15, T-20). Ecological correlations adjusted for human development index, smoking and obesity rates were calculated to evaluate the relationship between food availability and ASR of breast, prostate, colorectal, oesophageal, pancreatic, stomach and thyroid cancer.

RESULTS

Red meat was positively correlated with pancreatic cancer in men (T-20: r-20 = 0·61, P < 0·05), stomach cancer in women (T0: r0 = 0·58, P < 0·05), and colorectal cancer in men (T0: r0 = 0·53, P < 0·05) and women (T-20: r-20 = 0·58, P < 0·05). Animal products including meat, animal fats and higher animal-sourced energy supply tended to be positively correlated with breast, colorectal, pancreatic, stomach and thyroid cancer. Alcoholic beverages were positively correlated to oesophageal cancer in men (r0 = 0·69, P < 0·001) and women (r-20 = 0·72, P < 0·001).

CONCLUSIONS

The present analysis provides initial insights into the impact of alcoholic beverages, and increasing use of animal over plant products, on the incidence of specific cancers in Africa. The findings support the need for epidemiological studies to investigate the role of diet in cancer development in Africa.

Health Biomarkers in Adults Are More Closely Linked to Diet Quality Attributes Than to Plant-Based Diet Categorization

Although plant-based diets are promoted for healthy outcomes, these diets are not synonymous with high-quality diets. Plant-based diets can include highly processed, less healthful foods, including savory snacks, pastries, and sugary fruit drinks. This cross-sectional study examined the diet quality of vegetarian and omnivorous adults, matched for gender, age, and adiposity, and related diet quality to standard health biomarkers. Diet quality was assessed using the Rapid Eating and Activity Assessment for Participants Short Version questionnaire. Participants (17 vegetarians and 16 omnivores; 28.2 ± 8.9 years; 22.5 ± 2.7 kg/m²) were non-smokers and healthy by self-report. The median duration of adherence to the vegetarian diet was 27 months. Physical activity level and diet quality did not differ significantly between diet groups. Moreover, health biomarkers did not differ by diet groups. When participants were regrouped by low versus high diet quality, health biomarkers differed significantly between groups for fasting insulin, HOMA-IR, triglyceride (TG)/HDL ratio, and blood folate, with more favorable levels in the group with high diet quality. These data suggest that health biomarkers more closely align with diet quality attributes than with plant-based diet categorization. Thus, messaging focused on healthy diet attributes may lead to better health outcomes than the simple promotion of plant-based diets.