Plant-based dietary patterns and mortality from all causes, cardiovascular disease, and cancer: The Multiethnic Cohort Study

Associations between plant-based diets and cardiovascular disease, frailty, and cognitive dysfunction in middle and old age: a systematic review and meta-analysis of cohort studies

Background: Evidence suggests that plant-based diets are associated with multiple health outcomes. However, in previous pooled studies, the lack of a standardized definition of plant-based diet has led to conflicting evidence regarding its relationship with health outcomes in middle-aged and elderly people. Methods and findings: Searches were conducted on PubMed, Embase, Cochrane Library and Web of Science databases from inception until July 10, 2024. We included studies that examined the association between (1) the standardized healthy plant-based diet index (hPDI) and unhealthy plant-based diet index (uPDI) and (2) cardiovascular disease (CVD), cardiovascular mortality (CVD mortality), frailty, and cognitive dysfunction. Dose-response analysis was performed to assess the relationships between (1) hPDI and uPDI and (2) CVD and frailty. Statistical analyses were performed using an inverse variance random-effects model, and results are reported as risk ratio (RR) with 95% confidence interval (CI) by combining the most adjusted RR, odds ratio (OR) and hazard ratio (HR) under the rare outcome assumption. A total of 25 cohort studies were included. Higher hPDI scores were associated with lower risks of CVD (RR = 0.81, 95% CI 0.71-0.93), CVD mortality (RR = 0.83, 95% CI 0.75-0.90), coronary heart disease (CHD) (RR = 0.79, 95% CI 0.70-0.88), stroke (RR = 0.91, 95% CI 0.86-0.96), ischemic stroke (RR = 0.86, 95% CI 0.79-0.94), cognitive dysfunction (RR = 0.75, 95% CI 0.66-0.84) and frailty (RR = 0.72, 95% CI 0.60-0.86). By contrast, higher uPDI scores were associated with increased risks of CVD (RR = 1.16, 95% CI 1.09-1.24), CVD mortality (RR = 1.14, 95% CI 1.05-1.23), frailty (RR = 1.52, 95% CI 1.10-2.08) and cognitive dysfunction (RR = 1.24, 95% CI 1.11-1.38). Dose-response analyses showed that increasing adherence to hPDI was associated with reduced risks of CVD and frailty, whereas increasing intake of hPDI was linked to increased risk of CVD and frailty. Conclusions: Our study suggests that adherence to hPDI is associated with favourable health outcomes in middle-aged and elderly people, except for hemorrhagic stroke. These findings highlight the potential benefits of hPDI for promoting healthy ageing.

Existing food processing classifications overlook the phytochemical composition of processed plant-based protein-rich foods

According to existing food processing classification systems, plant-based protein-rich (PBPR) foods are often considered 'ultra-processed'-and therefore perceived as unhealthy-despite their ability to provide various bioactive compounds beneficial for human health. Here we used a non-targeted metabolomics approach to analyse the impact of processing on the biochemical composition of PBPR foods. Our results show that existing food classification systems may provide questionable categories for PBPR foods without considering their overall biochemical composition, including phytochemicals. An analysis focusing specifically on biochemical compounds of soy-based products manufactured using various technologies showed no clear distinctions between processing groups in the principal component analysis based on the NOVA and Poti classification. However, clear differences were found between soy-based products based on their phytochemical profile. Although food processing classification systems are welcome in their attempt to guide consumers towards healthy choices, they should be improved to more accurately reflect the biochemical composition of PBPR foods.

Plant-based diets and mortality in Black and low-income Americans: findings from a large prospective cohort study

BACKGROUND

Plant-based diets have been widely promoted for their health and environmental benefits. However, the health benefits may differ by the quality (i.e. healthiness) of plant foods, and few studies have specifically evaluated the association of plant-based diets with mortality in Black and low-income Americans who disproportionately experience poor health outcomes.

OBJECTIVES

We aimed to examine associations of plant-based dietary patterns with all-cause and cause-specific mortality in the Southern Community Cohort Study, a population-based prospective cohort conducted among predominantly Black and low-income Americans.

METHODS

Included in this study were 77,797 participants. Plant-based dietary patterns were assessed by established indices [i.e. overall plant-based diet index (PDI), healthy plant-based diet index (hPDI), unhealthy plant-based diet index (uPDI)] based on dietary intakes collected using a validated food frequency questionnaire at baseline (2002-2009). Mortality data were ascertained through 2022. Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for associations of PDI, hPDI, and uPDI with mortality from all, cardiovascular disease (CVD), cancer, and other nonexternal causes, adjusting for potential confounders.

RESULTS

During a median follow-up of 16.6 y, 27,269 deaths were identified. Compared with the lowest quintile, the highest quintile of PDI (HR = 0.87, 95% CI: 0.81, 0.93) and hPDI (HR = 0.82, 95% CI: 0.76, 0.89) was associated with reduced all-cause mortality (both Ptrend < 0.001). In contrast, a high uPDI was linked to elevated all-cause mortality (HR = 1.17, 95% CI: 1.08, 1.26 for the highest compared with lowest quintile, Ptrend < 0.001). Similar associations were observed for mortality from CVD and other causes. We also identified significant multiplicative interactions between hPDI and a composite measure of nondietary lifestyles in reducing all-cause and CVD mortality.

CONCLUSIONS

Adherence to a diet characterized by healthy plant foods and low animal foods may decrease mortality.

Associations Between Inflammatory Potential of Diet with the Risk of All-Cause Mortality and Greenhouse Gas Emissions in Chinese Adults

Background: Current research inadequately substantiates the impacts of dietary inflammatory potential based on the dietary inflammatory index (DII) on population health and environmental sustainability in Chinese adults. Objectives: We aimed to investigate the associations between the DII with the risk of all-cause mortality and greenhouse gas (GHG) emissions in Chinese adults. Methods: Data from adults (N = 15,318) in the China Health and Nutrition Survey 1997-2015 wave were included in the analysis. DII and energy-adjusted DII (E-DII) were calculated using dietary intake data collected with a combination of 3-day consecutive 24-h dietary recalls and the food weighing method. The total GHG emissions were calculated by summing the amount of emissions from all the food groups consumed by the participants. Cox proportional hazards regression models and linear regression models were conducted for statistical analysis. Results: A pro-inflammatory diet, as reflected by higher DII and E-DII scores was associated with an increased risk of all-cause mortality (DII: Q5 vs. Q1: HR = 1.82; 95% CI: 1.45-2.30; p-trend < 0.0001; E-DII: Q5 vs. Q1: HR = 1.86; 95% CI: 1.38-2.52; p-trend < 0.0001) and higher amounts of GHG emissions (both p-trend < 0.0001). Conclusions: These findings demonstrated positive associations between pro-inflammatory potentials with an increased risk of all-cause mortality and higher GHG emissions among Chinese adults, suggesting dual adverse impacts of a pro-inflammatory diet on health and environmental sustainability.

The association between overall, healthy, and unhealthy plant-based diet indexes and risk of all-cause and cause-specific mortality: a systematic review and dose-response meta-analysis of prospective cohort studies

Background: recent dietary guidelines recommend a diet that mainly includes plant-based foods and a moderate amount of animal products. Therefore, we hypothesized that plant-based diet indices (overall plant-based diet index (oPDI), healthy plant-based diet index (hPDI), and unhealthy plant-based diet index (uPDI)) might be associated with risk of all-cause and cause-specific mortality. Methods: a systematic review was conducted using PubMed, Web of Science, Scopus, and Embase databases until December 2024. Meta-analysis was performed utilizing random-effects models to calculate relative risk (RR) with the corresponding 95% confidence intervals (95% CIs). Results: from 436 initial records, 25 prospective studies met the inclusion criteria. The findings of our study indicated a modest inverse association between the adherence to oPDI and risk of all-cause mortality (RR [95% CI]: 0.89 [0.83-0.94]; n = 15 studies) as well as mortality related to cardiovascular diseases, chronic heart disease, and total cancer. Also, adherence to hPDI was found to reduce risk of all-cause (RR [95% CI]: 0.86 [0.82-0.90]; n = 21 studies), cardiovascular disease, chronic heart disease, total-cancer, and prostate cancer mortality, whereas uPDI was associated with higher risk of all-cause (RR [95% CI]: 1.20 [1.13-1.27]; n = 19 studies), cardiovascular disease, chronic heart disease, and total-cancer mortality. Our dose-response meta-analysis showed a monotonic inverse association between adherence to oPDI and hPDI and a positive linear association between adherence to uPDI and risk of all-cause mortality. Conclusion: our findings highlight the importance of evaluating the quality of plant-based foods as either healthy or unhealthy in relation to the risk of all-cause and cause-specific mortality.

Planetary Health Diet Index in relation to mortality in a prospective cohort study of United States Black females

BACKGROUND

To improve both human health and the health of our planet, the EAT-Lancet Commission proposed the planetary health diet (PHD).

OBJECTIVES

We aimed to evaluate associations of PHD with all-cause, cardiovascular disease (CVD), and cancer-specific mortality among United States Black females.

METHODS

The Black Women's Health Study is a prospective study of self-identified United States Black females. In 2001, 33,824 participants free of cancer and CVD completed a validated food frequency questionnaire. PHD Index (PHDI) was calculated based on reported consumption of 15 food groups, such as whole grains, nonstarchy vegetables, legumes, soy foods, added fat and trans fat, and red/processed meats. Deaths were identified through linkage to the National Death Index. Cox proportional hazards regression, stratified by age and adjusted for smoking status, body mass index, and other CVD risk factors, was used to calculate hazard ratios (HRs) for quintiles of PHDI in relation to all-cause, CVD-, and cancer-specific mortality.

RESULTS

During 18 years of follow-up, we identified 3537 deaths, including 779 from CVD and 1625 from cancer. Females in the quintile representing the highest adherence to PHD were estimated to have an 18% reduction in risk of all-cause mortality [HR = 0.82, 95% confidence interval (CI): 0.71, 0.94] and 26% reduction in CVD-specific mortality (HR = 0.74, 95% CI: 0.55, 0.98), compared with those in the lowest quintile, with similar reductions observed for quintiles 2, 3, and 4. Among individuals under age 55, there was a significant trend of lower CVD mortality risk with a higher level of adherence to PHD (Ptrend = 0.004), and the HR for the highest compared with the lowest quintile was 0.43 (95% CI: 0.21, 0.87). PHDI was not associated with cancer-specific mortality.

CONCLUSIONS

Adherence to a diet that has been shown to benefit the planet was associated with a lower risk of mortality among Black females, primarily driven by a reduction in CVD-specific mortality risk.

Plant-based diets and total and cause-specific mortality: a meta-analysis of prospective studies

Objective

The adherence to plant-based diets has been shown to positively impact longevity by reducing the incidence and severity of lifestyle-related diseases. Previous studies on the association of plant-based dietary pattern, as evaluated by plant-based dietary index (PDI), healthy plant-based dietary index (hPDI) and unhealthy plant-based dietary index (uPDI), with mortality risk have reported inconsistent results. We performed the present meta-analysis to summarize evidence on this association and to quantify the potential dose-response relationship based on all available cohort studies.

Methods

A comprehensive literature search and systematic review of relevant articles up to October 2024 was performed in PubMed and Scopus. The summary risk estimates (RR) with 95% confidence interval (CI) for the highest versus the lowest category of PDIs, hPDIs and uPDIs were calculated. Dose-response meta-analysis was also performed for studies reporting categorical risk estimates for at least three quantitative levels of PDIs, hPDIs and uPDIs.

Results

A total of 11 eligible cohort studies (13 datasets) were eventually included in this meta-analysis. Participants in the highest quintile of both the PDI and hPDI had a significantly decreased risk of all-cause mortality (pooled HRPDI = 0.85; 95% CI: 0.80-0.90; pooled HRhPDI = 0.86; 95% CI: 0.81-0.92) compared to participants in the lowest quintile. In contrast, the highest uPDI was associated with an increased risk of mortality (pooled HRuPDI = 1.20; 95% CI: 1.11-1.31). Dose-response meta-analysis showed that there was a non-linear relationship between PDI or hPDI level and all-cause mortality (p = 0.001 and p < 0.001 for non-linearity, respectively). No evidence of a non-linear relationship was observed for uPDI (p = 0.596 for non-linearity).

Conclusion

Greater adherence to PDI or hPDI dietary pattern was associated with a lower risk of mortality, whereas uPDI dietary pattern was positively associated with mortality risk. Thus, promoting a plant-based dietary pattern may be a key strategy in improving public health and reducing the burden of diet-related mortality.

Plant-based diet and risk of all-cause mortality: a systematic review and meta-analysis

Objective

A systematic analysis was conducted to determine the relationship between a plant-based diet and all-cause mortality.

Methods

The PubMed, Embase and Web of Science databases were searched. Two authors selected English documents from the database. Then the other two authors extracted the data and evaluated the Newcastle-Ottawa Scale (NOS). This study adhered to the guidelines of the Preferred Reporting Project (PRISMA) and the PROSPERO Registry protocols. A mixed-effects model combined maximum adjusted estimates, with heterogeneity measured using the I2 statistic. The sensitivity analysis validated the analysis's robustness, while publication bias was assessed.

Results

The results of the meta-analysis of 14 articles revealed that a plant-based diet (PDI) can reduce cancer mortality (RR = 0.88, [95% CI 0.79-0.98], τ2: 0.02, I2: 84.71%), cardiovascular disease (CVD) mortality (RR = 0.81, [95% CI 0.76-0.86], τ2: 0.00, I2: 49.25%) and mortality (RR = 0.84, [95% CI 0.79-0.89], τ2: 0.01, I2: 81.99%) risk. Adherence to a healthy plant-based diet (hPDI) was negatively correlated with cancer mortality (RR = 0.91, [95% CI 0.83-0.99], τ2:0.01, I2:85.61%), CVD mortality (RR = 0.85, [95% CI 0.77-0.94], τ2: 0.02, I2: 85.13%) and mortality (RR = 0.85, [95% CI 0.80-0.90], τ2: 0.01, I2: 89.83%). An unhealthy plant-based diet (uPDI) was positively correlated with CVD mortality (RR = 1.19, [95% CI 1.07-1.32], τ2: 0.02, I2: 80.03%) and mortality (RR = 1.18, [95% CI 1.09-1.27], τ2: 0.01, I2: 89.97%) and had a certain correlation with cancer mortality (RR = 1.10, [95% CI 0.97-1.26], τ2: 0.03, I2: 93.11%). Sensitivity analysis showed no contradictory results.

Conclusion

The hPDI was negatively associated with all-cause mortality, and the uPDI was positively associated with all-cause mortality.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/#loginpage.