Healthy Plant-Based Diets Are Associated with Lower Risk of All-Cause Mortality in US Adults

Plant-Based Dietary Patterns, Plant Foods, and Age-Related Cognitive Decline

The aging population is expanding, as is the prevalence of age-related cognitive decline (ARCD). Of the several risk factors that predict the onset and progression of ARCD, 2 important modifiable risk factors are diet and physical activity. Dietary patterns that emphasize plant foods can exert neuroprotective effects. In this comprehensive review, we examine studies in humans of plant-based dietary patterns and polyphenol-rich plant foods and their role in either preventing ARCD and/or improving cognitive function. As yet, there is no direct evidence to support the benefits of a vegetarian diet in preventing cognitive decline. However, there is emerging evidence for brain-health-promoting effects of several plant foods rich in polyphenols, anti-inflammatory dietary patterns, and plant-based dietary patterns such as the Mediterranean diet that include a variety of fruits, vegetables, legumes, nuts, and whole grains. The bioactive compounds present in these dietary patterns include antioxidant vitamins, polyphenols, other phytochemicals, and unsaturated fatty acids. In animal models these nutrients and non-nutrients have been shown to enhance neurogenesis, synaptic plasticity, and neuronal survival by reducing oxidative stress and neuroinflammation. In this review, we summarize the mounting evidence in favor of plant-centered dietary patterns, inclusive of polyphenol-rich foods for cognitive well-being. Randomized clinical trials support the role of plant foods (citrus fruits, grapes, berries, cocoa, nuts, green tea, and coffee) in improving specific domains of cognition, most notably frontal executive function. We also identify knowledge gaps and recommend future studies to identify whether plant-exclusive diets have an added cognitive advantage compared with plant-centered diets with fish and/or small amounts of animal foods.

2019 ACC/AHA Guideline on the Primary Prevention of Cardiovascular Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines

A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines

Endorsed by the American Association of Cardiovascular and Pulmonary Rehabilitation, the American Geriatrics Society, the American Society of Preventive Cardiology, and the Preventive Cardiovascular Nurses Association

2019 ACC/AHA Guideline on the Primary Prevention of Cardiovascular Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines

1. The most important way to prevent atherosclerotic vascular disease, heart failure, and atrial fibrillation is to promote a healthy lifestyle throughout life.

2. A team-based care approach is an effective strategy for the prevention of cardiovascular disease. Clinicians should evaluate the social determinants of health that affect individuals to inform treatment decisions.

3. Adults who are 40 to 75 years of age and are being evaluated for cardiovascular disease prevention should undergo 10-year atherosclerotic cardiovascular disease (ASCVD) risk estimation and have a clinician–patient risk discussion before starting on pharmacological therapy, such as antihypertensive therapy, a statin, or aspirin. The presence or absence of additional risk-enhancing factors can help guide decisions about preventive interventions in select individuals, as can coronary artery calcium scanning.

4. All adults should consume a healthy diet that emphasizes the intake of vegetables, fruits, nuts, whole grains, lean vegetable or animal protein, and fish and minimizes the intake of trans fats, processed meats, refined carbohydrates, and sweetened beverages. For adults with overweight and obesity, counseling and caloric restriction are recommended for achieving and maintaining weight loss.

5. Adults should engage in at least 150 minutes per week of accumulated moderate-intensity physical activity or 75 minutes per week of vigorous-intensity physical activity.

6. For adults with type 2 diabetes mellitus, lifestyle changes, such as improving dietary habits and achieving exercise recommendations are crucial. If medication is indicated, metformin is first-line therapy, followed by consideration of a sodium-glucose cotransporter 2 inhibitor or a glucagon-like peptide-1 receptor agonist.

7. All adults should be assessed at every healthcare visit for tobacco use, and those who use tobacco should be assisted and strongly advised to quit.

8. Aspirin should be used infrequently in the routine primary prevention of ASCVD because of lack of net benefit.

9. Statin therapy is first-line treatment for primary prevention of ASCVD in patients with elevated low-density lipoprotein cholesterol levels (≥190 mg/dL), those with diabetes mellitus, who are 40 to 75 years of age, and those determined to be at sufficient ASCVD risk after a clinician–patient risk discussion.

10. Nonpharmacological interventions are recommended for all adults with elevated blood pressure or hypertension. For those requiring pharmacological therapy, the target blood pressure should generally be <130/80 mm Hg.

Changes in Plant-Based Diet Quality and Total and Cause-Specific Mortality

BACKGROUND

Plant-based diets have been associated with lower risk of type 2 diabetes mellitus and cardiovascular disease (CVD) and are recommended for both health and environmental benefits. However, the association between changes in plant-based diet quality and mortality remains unclear.

METHODS

We investigated the associations between 12-year changes (from 1986 to 1998) in plant-based diet quality assessed by 3 plant-based diet indices (score range, 18-90)-an overall plant-based diet index (PDI), a healthful PDI, and an unhealthful PDI-and subsequent total and cause-specific mortality (1998-2014). Participants were 49 407 women in the Nurses' Health Study (NHS) and 25 907 men in the Health Professionals Follow-Up Study (HPFS) who were free from CVD and cancer in 1998. Multivariable-adjusted Cox proportional-hazards models were used to estimate hazard ratios (HRs) and 95% CIs.

RESULTS

We documented 10 686 deaths including 2046 CVD deaths and 3091 cancer deaths in the NHS over 725 316 person-years of follow-up and 6490 deaths including 1872 CVD deaths and 1772 cancer deaths in the HPFS over 371 322 person-years of follow-up. Compared with participants whose indices remained stable, among those with the greatest increases in diet scores (highest quintile), the pooled multivariable-adjusted HRs for total mortality were 0.95 (95% CI, 0.90-1.00) for PDI, 0.90 (95% CI, 0.85-0.95) for healthful PDI, and 1.12 (95% CI, 1.07-1.18) for unhealthful PDI. Among participants with the greatest decrease (lowest quintile), the multivariable-adjusted HRs were 1.09 (95% CI, 1.04-1.15) for PDI, 1.10 (95% CI, 1.05-1.15) for healthful PDI, and 0.93 (95% CI, 0.88-0.98) for unhealthful PDI. For CVD mortality, the risk associated with a 10-point increase in each PDI was 7% lower (95% CI, 1-12%) for PDI, 9% lower (95% CI, 4-14%) for healthful PDI, and 8% higher (95% CI, 2-14%) for unhealthful PDI. There were no consistent associations between changes in plant-based diet indices and cancer mortality.

CONCLUSIONS

Improving plant-based diet quality over a 12-year period was associated with a lower risk of total and CVD mortality, whereas increased consumption of an unhealthful plant-based diet was associated with a higher risk of total and CVD mortality.

Plant-Based Diets Are Associated With a Lower Risk of Incident Cardiovascular Disease, Cardiovascular Disease Mortality, and All-Cause Mortality in a General Population of Middle-Aged Adults

Background

Previous studies have documented the cardiometabolic health benefits of plant‐based diets; however, these studies were conducted in selected study populations that had narrow generalizability.

Methods and Results

We used data from a community‐based cohort of middle‐aged adults (n=12 168) in the ARIC (Atherosclerosis Risk in Communities) study who were followed up from 1987 through 2016. Participants’ diet was classified using 4 diet indexes. In the overall plant‐based diet index and provegetarian diet index, higher intakes of all or selected plant foods received higher scores; in the healthy plant‐based diet index, higher intakes of only the healthy plant foods received higher scores; in the less healthy plant‐based diet index, higher intakes of only the less healthy plant foods received higher scores. In all indexes, higher intakes of animal foods received lower scores. Results from Cox proportional hazards models showed that participants in the highest versus lowest quintile for adherence to overall plant‐based diet index or provegetarian diet had a 16%, 31% to 32%, and 18% to 25% lower risk of cardiovascular disease, cardiovascular disease mortality, and all‐cause mortality, respectively, after adjusting for important confounders (all P<0.05 for trend). Higher adherence to a healthy plant‐based diet index was associated with a 19% and 11% lower risk of cardiovascular disease mortality and all‐cause mortality, respectively, but not incident cardiovascular disease (P<0.05 for trend). No associations were observed between the less healthy plant‐based diet index and the outcomes.

Conclusions

Diets higher in plant foods and lower in animal foods were associated with a lower risk of cardiovascular morbidity and mortality in a general population.

A Provegetarian Food Pattern Emphasizing Preference for Healthy Plant-Derived Foods Reduces the Risk of Overweight/Obesity in the SUN Cohort

Provegetarian diets (i.e., preference for plant-derived foods but not exclusion of animal foods) have been associated with a reduced risk of long-term weight gain and could be more easily embraced than strict vegetarian diets. However, not all plant-derived foods are equally healthy. In the “Seguimiento Universidad de Navarra” (SUN) cohort, we prospectively evaluated the association between different provegetarian food patterns and the incidence of overweight/obesity in 11,554 participants with initial body mass index <25 kg/m². A provegetarian food pattern (FP) was built by assigning positive scores to plant foods and reverse scores to animal foods. A healthful and an unhealthful provegetarian FP, which distinguished between healthy (fruits/vegetables/whole grains/nuts/legumes/olive oil/coffee) and less-healthy plant foods (fruit juices/potatoes/refined grains/pastries/sugary beverages), were also built. A total of 2320 new cases of overweight or obesity were identified after a median follow-up of 10.3 years. Higher baseline conformity with the overall provegetarian FP was inversely associated with overweight/obesity (HR comparing extreme quintiles: 0.85; 95% CI: 0.75 to 0.96; p-trend: 0.014). This association was stronger for the healthful FP (HR: 0.78; 95% CI: 0.67 to 0.90; p-trend: <0.001) and was not apparent for the unhealthful FP (HR: 1.07; 95% CI: 0.92 to 1.23; p-trend: 0.551). In a large prospective cohort of relatively young adults, better conformity with a healthy provegetarian diet was associated with a reduced long-term risk of overweight/obesity, whereas no consistent trend was found for a FP that emphasized less-healthy plant foods.

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.

Plant-Based Diets and Incident CKD and Kidney Function

BACKGROUND AND OBJECTIVES

The association between plant-based diets, incident CKD, and kidney function decline has not been examined in the general population. We prospectively investigated this relationship in a population-based study, and evaluated if risk varied by different types of plant-based diets.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Analyses were conducted in a sample of 14,686 middle-aged adults enrolled in the Atherosclerosis Risk in Communities study. Diets were characterized using four plant-based diet indices. In the overall plant-based diet index, all plant foods were positively scored; in the healthy plant-based diet index, only healthful plant foods were positively scored; in the provegetarian diet, selected plant foods were positively scored. In the less healthy plant-based diet index, only less healthful plant foods were positively scored. All indices negatively scored animal foods. We used Cox proportional hazards models to study the association with incident CKD and linear mixed models to examine decline in eGFR, adjusting for confounders.

RESULTS

During a median follow-up of 24 years, 4343 incident CKD cases occurred. Higher adherence to a healthy plant-based diet (HR comparing quintile 5 versus quintile 1 [HRQ5 versus Q1], 0.86; 95% confidence interval [95% CI], 0.78 to 0.96; P for trend =0.001) and a provegetarian diet (HRQ5 versus Q1, 0.90; 95% CI, 0.82 to 0.99; P for trend =0.03) were associated with a lower risk of CKD, whereas higher adherence to a less healthy plant-based diet (HRQ5 versus Q1, 1.11; 95% CI, 1.01 to 1.21; P for trend =0.04) was associated with an elevated risk. Higher adherence to an overall plant-based diet and a healthy plant-based diet was associated with slower eGFR decline. The proportion of CKD attributable to lower adherence to healthy plant-based diets was 4.1% (95% CI, 0.6% to 8.3%).

CONCLUSIONS

Higher adherence to healthy plant-based diets and a vegetarian diet was associated with favorable kidney disease outcomes.

Validity of the Mediterranean Diet and Culinary Index (MediCul) for Online Assessment of Adherence to the 'Traditional' Diet and Aspects of Cuisine in Older Adults

The Mediterranean diet is associated with multiple health benefits. Yet, no tool has been specifically developed to assess adherence to the 'traditional' Mediterranean diet and cuisine within a Western cohort, and validated for online use. We tested the reliability and validity of online administration of the Mediterranean Diet and Culinary Index (MediCul) among middle-aged and older adults. Participants were recruited in January⁻March 2017 from the 45 and Up Study, completing MediCul twice. Test-retest reliability was assessed using the paired t-test, intra-class correlation coefficient (ICC) and Bland-Altman plot. Validity was tested against a three-day food record (FR)-derived MediCul score using Bland-Altman and nutrient trends across the MediCul score tertiles. Participants (n = 84; 60% female; 65.4 years (SD = 5.9)), were overweight (BMI 26.1; SD = 4.0) with 1.7 (SD = 1.5) chronic illnesses/conditions. Sequential MediCul tool scores were 56.1/100.0 and 56.8/100.0, respectively (t = -1.019; p = 0.311). Reliability via ICC (ICC = 0.86, 95% CI: 0.789, 0.910, p < 0.0001) and Bland-Altman was good. In Bland-Altman validity analyses, the tool over-reported FR MediCul score by 5.6 points with no systematic bias ((y = 8.7 - 0.06*x) (95% CI: -0.278, 0.158, p = 0.584)). Nutrient trends were identified for MediCul consistent with expected Mediterranean patterns. Online MediCul administration demonstrated good reliability and moderate validity for assessing adherence to a 'traditional' Mediterranean pattern among older Australians.