Plant-based diet quality and the risk of total and disease-specific mortality: A population-based prospective study.

BACKGROUND AND AIMS: Plant-based diets have been suggested to have health benefits, and risk differs by quality of plant foods. However, evidence on the association between the quality of plant-based diets and mortality are limited. This study examined the associations between 3 different types of plant-based diet indices and risk of total and disease-specific mortality. METHODS: Analyses were based on a population-based cohort of 118,577 South Korean adults (40-69 years of age) who participated in the Korean Genome and Epidemiology Study_Health Examinees (2004-2019). Dietary intakes were assessed using a validated food frequency questionnaire. Based on the questionnaire, we calculated 3 plant-based diet indices: overall plant-based diet index (PDI), healthful plant-based diet index (hPDI), and unhealthful plant-based diet index (uPDI). The PDI assigned higher scores for higher consumption of all plant foods. The hPDI assigned higher scores for higher consumption of only healthy plant foods. The uPDI assigned higher scores for higher consumption of only unhealthy plant foods. RESULTS: During a total of 1,191,426 person-years of follow-up, we ascertained 3074 deaths, including 447 deaths from cardiovascular disease and 1515 deaths from cancer. Comparing the highest versus lowest quintiles of PDI, the multivariable-adjusted hazard ratios of total mortality were 0.76 (95% CI, 0.68-0.85, P-trend<0.0001). Comparing the highest versus lowest quintile of uPDI, the hazard ratios were 1.30 for total mortality (95% CI, 1.15-1.48, P-trend<0.0001), 1.55 for cardiovascular disease mortality (95% CI, 1.08-2.25, P-trend = 0.06), and 1.23 for cancer mortality (95% CI, 1.02-1.47, P-trend = 0.06) after adjustment for demographic characteristics and lifestyle factors. For 10-point higher in PDI score was associated with 13% (95% CI, 0.82-0.92, P < 0.0001) lower risk of total mortality. In contrast, 10-point higher in uPDI score was associated with 16% (95% CI, 1.06-1.17, P < 0.0001) higher risk of total mortality with modest association with cancer mortality. No association was observed between hPDI and any cause of mortality. The correlation coefficients were 0.39 between PDI and hPDI, -0.22 between hPDI and uPDI, and 0.07 between PDI and uPDI. CONCLUSIONS: Overall, greater adherence to a plant-based dietary pattern was associated with lower total mortality, but among those with predominantly unhealthful plant-based diets, total and disease-specific mortality rates were higher. The quality of plant foods may be crucial for reducing mortality in a population that mainly consume diets rich in plant foods.

Veganism, aging and longevity: new insight into old concepts.

PURPOSE OF REVIEW: Plant-based diets are associated with better health and longevity. Veganism is a strict form of vegetarianism, which has gained increasing attention in recent years. This review will focus on studies addressing mortality and health-span in vegans and vegetarians and discuss possible longevity-enhancing mechanisms. RECENT FINDINGS: Studies in vegans are still limited. Epidemiologic studies consistently show lower disease rates, such as lower incidence of cancer and cardiovascular disease, but mortality rates are comparable with rates in vegetarians and occasional meat eaters. Reasons for following strict vegan diets differ, which may affect diet quality, and thus health and life-span. New insights into some characteristics of veganism, such as protein restriction or restriction in certain amino acids (leucine or methionine) show potentially life-span-enhancing potential. Veganism improves insulin resistance and dyslipidemia and associated abnormalities. Gut microbiota as mediator of dietary impact on host metabolism is more diverse in vegans and has been suggested to be a health-promoting factor. Vegan diets do not fulfill the requirements of children, pregnant women or old individuals who should receive adequate supplements. SUMMARY: There is substantial evidence that plant-based diets are associated with better health but not necessarily lower mortality rates. The exact mechanisms of health promotion by vegan diets are still not entirely clear but most likely multifactorial. Reasons for and quality of the vegan diet should be assessed in longevity studies.

Coronary heart disease mortality among Seventh-Day Adventists with differing dietary habits: a preliminary report.

Seventh-Day Adventists (SDAs) are a conservative religious denomination who abstain from tobacco and alcohol; approximately one-half follow a lacto-ovo-vegetarian diet. In this 6-year prospective study of 24,044 California SDAs age 35 and over, coronary heart disease (CHD) mortality rates for ages 35 to 64 and 65+ are 28% and 50% respectively, of the rates for the same age groups of the total California population. This reduced risk of CHD mortality among SDAs is partially due to abstinence from smoking; however, at least half the low risk among SDAs is likely attributable to other characteristics of the SDA lifestyle. The risk of fatal CHD among nonvegetarian SDA males, ages 35 to 64, is three times greater than vegetarian SDA males of comparable age (P less than 0.01), suggesting that the SDA diet may account for a large share of their low risk. This differential was much smaller for older SDA males and SDA females. Although the differential in risk of fatal CHD for male nonvegetarians versus vegetarians may be partially accounted for by other CHD risk factors, which are more frequent among nonvegetarians, a significant differential persists after adjustment for each of six other CHD risk factors.