Diet strategies for promoting healthy aging and longevity: An epidemiological perspective

Abstract

In recent decades, global life expectancies have risen significantly, accompanied by a marked increase in chronic diseases and population aging. This narrative review aims to summarize recent findings on the dietary factors influencing chronic diseases and longevity, primarily from large cohort studies. First, maintaining a healthy weight throughout life is pivotal for healthy aging and longevity, mirroring the benefits of lifelong, moderate calorie restriction in today's obesogenic food environment. Second, the specific types or food sources of dietary fat, protein, and carbohydrates are more important in influencing chronic disease risk and mortality than their quantity. Third, some traditional diets (e.g., the Mediterranean, Nordic, and Okinawa) and contemporary dietary patterns, such as healthy plant-based diet index, the DASH (dietary approaches to stop hypertension) diet, and alternate healthy eating index, have been associated with lower mortality and healthy longevity. These patterns share many common components (e.g., a predominance of nutrient-rich plant foods; limited red and processed meats; culinary herbs and spices prevalent in global cuisines) while embracing distinct elements from different cultures. Fourth, combining a healthy diet with other lifestyle factors could extend disease-free life expectancies by 8-10 years. While adhering to core principles of healthy diets, it is crucial to adapt dietary recommendations to individual preferences and cultures as well as nutritional needs of aging populations. Public health strategies should aim to create a healthier food environment where nutritious options are readily accessible, especially in public institutions and care facilities for the elderly. Although further mechanistic studies and human trials are needed to better understand molecular effects of diet on aging, there is a pressing need to establish and maintain long-term cohorts studying diet and aging in culturally diverse populations.

Keywords: aging; cardiovascular risk factors; diet; epidemiology; nutrition; physiology.

Figure 1.. Associations of Weight Gain from Early to Middle Adulthood with Risk of Individual Health Outcomes

After adjustment for age at cohort recruitment (continuous), height (continuous), race (nonwhite or white), pack-years of smoking (never smokers; past smoker with <5, 5–20, or >20 pack-years; and current smoker with <5, 5–20, or >20 pack-years), regular aspirin use (yes or no), status of menopause and hormone therapy (women only: premenopausal, postmenopausal and never use, postmenopausal and current use, or postmenopausal and past use), parity (women only: nulliparous, 1, 2, 3, or ≥4 children), physical activity, alcohol consumption dietary qualify (Alternative Healthy Eating Index in quintiles), family history of respective diseases and weight at age of 18 years in women and at age of 21 years in men. Obesity-related cancer includes the esophagus (adenocarcinoma only), colon and rectum, pancreas, breast (after menopause, women only), endometrium (women only), ovaries (women only), prostate (advanced only, men only), kidney, liver, and gallbladder. ^aA composite healthy aging outcome was defined as being free of 11 chronic diseases and major cognitive or physical impairment. Expressed as odds ratio (95% CI) per 5-kg weight gain. Reproduced with permission from JAMA. 2017. 318(3):255–69. doi: 10.1001/jama.2017.7092. Copyright©(2017) American Medical Association. All rights reserved. (superficially modified)

Figure 2.

Change in total mortality risk associated with increments of calorie intake from specific types of fat in the Nurses’ Health Study and Health Professionals Follow-Up Study. Multivariable HRs are shown for total mortality associated with replacing the percentage of energy from total carbohydrates with the same energy from specific types of fat (P-trend < 0.001 for all), adjusted for age, race, marital status, BMI, physical activity, smoking status, alcohol consumption, multivitamin use, vitamin E supplement use, current aspirin use, family history of myocardial infarction, family history of diabetes, family history of cancer, history of hypertension, history of hypercholesterolemia, intakes of total energy and dietary cholesterol, percentage of energy intake from dietary protein, menopausal status and hormone use in women, and percentage of energy from the remaining specific types of fat. Figure originally published in Hemler C, Hu F, ^“Plant-Based Diets for Personal, Population, and Planetary Health” Advances in Nutrition, 2019 Nov; 10(Suppl 4): S275–S283. https://advances.nutrition.org/. Reproduced with permission (superficially modified).

Figure 3.

Healthy Eating Plate: The Nutrition Source Copyright © 2011 Harvard University. For more information about The Healthy Eating Plate, see The Nutrition Source, Department of Nutrition, Harvard T.H. Chan School of Public Health, http://www.thenutritionsource.org and Harvard Health Publications, health.harvard.edu.

Figure 4.. Life expectancy estimated based on overall mortality rate of Americans (CDC report), the prevalence of lifestyle factors using NHANES data 2013–2014 and age- and sex-specific hazard ratios (A: hazard ratio; B: life expectancy at age 50; C: life expectancy by age)*, ^†

*Low-risk lifestyle factors included: cigarette smoking (never smoking), physically active (≥3.5 hours/week moderate to vigorous intensity activity), high diet quality (upper 40% of alternative healthy eating index (AHEI), moderate alcohol intake of 5–15 g/day (female) or 5–30 g/day (male), and normal weight (body mass index <25 kg/m²). ^†The estimates of cumulative survival from 50 years of age onward among the 5 lifestyle risk factor groups were calculated by applying: (1) all-cause and cause-specific mortality rates were obtained from the US CDC WONDER database; (2) distribution of different numbers of low-risk lifestyles was based on the US NHANES 2013–2014; (3) multivariate-adjusted hazard ratios (sex-and age-specific) for all-cause mortality associated with the 5 low-risk lifestyles as compared to those without any low-risk lifestyle factors, adjusted for ethnicity, current multivitamin use, current aspirin use, family history of diabetes mellitus, myocardial infarction, or cancer, and menopausal status and hormone use (females only), were based on data from the NHS and HPFS. Figure originally published in Li Y, Pan A, Wang DD, Liu X, Dhana K, Franco OH, et al. “Impact of Healthy Lifestyle Factors on Life Expectancies in the US Population.” Circulation. 2018;138(4):345–55. https://www.ahajournals.org/journal/circ. Reproduced with permission.