The global population of older adults is steadily increasing, with a significant proportion facing chronic health conditions. In the US, 80% of older adults have at least one chronic health condition, highlighting the complex health challenges facing this demographic shift. Promoting healthy aging is therefore a global priority, driven by the goal of enhancing the quality of life, enabling continued societal contributions, and reducing healthcare costs. As the leading behavioral risk factor for noncommunicable diseases and mortality globally, and second only to tobacco use in US older adults, diet plays a crucial role in healthy aging.
The Shift Towards Healthy Aging
The World Health Organization has acknowledged the importance of preserving functional ability and preventing capacity decline in older adults. This shift moves away from the traditional disease-centric approach to aging, aiming to offer older adults enhanced care. Intervention and observational studies have provided compelling evidence that a better-quality diet is beneficial for the prevention of cardiovascular disease, type 2 diabetes, and premature mortality. Studies have also evaluated the effects or the associations of foods and nutrients with age-related cognitive and physical performance outcomes and depressive symptoms. Examining and contrasting dietary patterns in relation to healthy aging will inform public health recommendations aimed at fostering the overall health and well-being of older adults, encompassing cognitive, physical and mental health, and the prevention of chronic diseases.
Examining Dietary Patterns and Healthy Aging
Recent studies have examined the association between long-term adherence to various healthy dietary patterns and healthy aging outcomes. These dietary patterns include the Alternative Healthy Eating Index (AHEI), Alternative Mediterranean Index (aMED), the Dietary Approaches to Stop Hypertension (DASH), the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND), the healthful plant-based diet (hPDI), the Planetary Health Diet Index (PHDI), the empirically inflammatory dietary pattern (EDIP), the empirical dietary index for hyperinsulinemia (EDIH) and ultraprocessed food (UPF) consumption. Researchers have analyzed how these patterns correlate with healthy aging over extended periods, considering various subgroups based on sex, ancestry, socioeconomic status (SES), and lifestyle factors. Additionally, the associations of individual foods and nutrients contributing to these dietary patterns have been examined.
Study Results: Dietary Patterns and Healthy Aging
One study involving 105,015 participants (70,091 women and 34,924 men) followed over 30 years, revealed that higher adherence to all dietary patterns was associated with greater odds of healthy aging. Specifically, 9,771 (9.3%) participants achieved healthy aging, with 7,602 (10.8%) in the NHS and 2,169 (6.2%) in the HPFS. In the pooled cohorts, 39,769 (37.9%) reached the age of 70 years, 23,908 (22.8%) remained free of 11 chronic diseases, 35,555 (33.9%) maintained intact cognitive function, 29,543 (28.1%) maintained intact physical function and 27,842 (26.5%) maintained intact mental health. The multivariable-adjusted odds ratios (ORs) comparing the highest quintile to the lowest ranged from 1.45 to 1.86, with the AHEI showing the strongest association followed by the rEDIH, and the hPDI showing the weakest association.
The AHEI showed higher odds of healthy aging compared to the MIND, hPDI and rEDIP. The aMED, DASH, PHDI and rEDIH also demonstrated higher odds of healthy aging compared to the hPDI. Using dietary pattern scores modeled as continuous variables, the associations with healthy aging were also the strongest for the AHEI and the weakest for the hPDI. The OR per standardized unit increase ranged from 1.40 to 1.71. Absolute risks, calculated based on the healthy aging prevalence and adjusted ORs, indicated 8.4% to 12.4% chances of achieving healthy aging among individuals with higher adherence to the dietary patterns.
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Impact on Specific Domains of Healthy Aging
Higher adherence to all dietary patterns was associated with all individual domains of healthy aging. For intact cognitive health, the ORs ranged from 1.22 to 1.65, with the PHDI showing the strongest association and the hPDI showing the weakest association. For intact physical function, the ORs ranged from 1.38 to 2.30, with the AHEI showing the strongest association and the rEDIP showing the weakest association. For intact mental health, the ORs ranged from 1.37 to 2.03, with the AHEI showing the strongest association and the hPDI showing the weakest association. For being free of chronic diseases, the ORs ranged from 1.32 to 1.75, with the rEDIH showing the strongest association and the hPDI showing the weakest association. For surviving to the age of 70 years, the ORs ranged from 1.33 to 2.17, with the PHDI showing the strongest association and the hPDI showing the weakest association.
The Role of Individual Dietary Factors
Individual dietary factors also play a significant role in healthy aging. Higher intakes of fruits, whole grains, vegetables, added unsaturated fats, nuts, legumes, and low-fat dairy were associated with greater odds of healthy aging, while higher intakes of trans fats, sodium, total meats, and red and processed meats were associated with lower odds. These foods or nutrients were also consistently associated with each healthy aging domain. Added unsaturated fat intake, including polyunsaturated fatty acids, was particularly associated with surviving to the age of 70 years, and intact physical and cognitive functions.
Subgroup Analysis: Gender, Lifestyle, and Socioeconomic Status
Adherence to all dietary patterns was significantly associated with healthy aging in both men and women, but the associations were stronger in women, except for rEDIH and rEDIP. The associations were also stronger in smokers, in participants with a BMI greater than 25 kg m−2, and in participants with a physical activity level below the median. A significant interaction between SES and rEDIH/rEDIP was observed, while no interaction was found for ancestry.
The Detrimental Effects of Ultra-Processed Foods
Higher UPF consumption was associated with 32% lower odds of healthy aging. Higher consumption of UPFs was also associated with lower odds of maintaining intact cognitive function, physical function and mental health, living free of chronic diseases and reaching the age of 70 years.
Diet Quality and Chronic Diseases
Studies have also examined the relationship between diet quality and chronic diseases, revealing important insights into how dietary habits of individuals with chronic conditions compare to those without.
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Diet Quality Among Patients vs. Non-Patients
One study using nationally representative data found that adults with diet-related chronic diseases reported somewhat higher diet quality than non-patients, especially among those patients with good nutrition knowledge and beliefs (NKB) and use of food labels (FL). Patients’ mean Healthy Eating Index (HEI) was higher than that of non-patients (53.6 vs. 51.8). However, the positive association between chronic diseases and HEI was observed only for patients with good NKB. The diabetes-HEI association was stronger among FL users than non-FL users.
Racial and Ethnic Disparities in Diet Quality
Among patients, blacks were more likely to report low diet quality than whites. Stratified analyses showed that NH blacks with and without any disease had higher intakes of cholesterol and fat than did NH whites. This highlights the racial and ethnic disparities in diet quality and the need for targeted interventions to address these differences.
The Role of Nutrition Knowledge and Food Label Use
The study also found that the disease-diet association was only significant among people with good NKB. The significant association for high HEI was observed for diabetes among FL users but not in nonusers. This underscores the importance of nutrition education and promoting food label literacy to improve dietary habits, especially among individuals with chronic diseases.
A Global Perspective on Healthy Diets
Research conducted across multiple countries provides a broader understanding of the impact of diet on cardiovascular health and mortality.
The PURE Study: A Healthy Diet Score
The Prospective Urban Rural Epidemiology (PURE) study developed a healthy diet score based on six foods associated with a significantly lower risk of mortality: fruit, vegetables, nuts, legumes, fish, and dairy (mainly whole-fat). The study found that a higher diet score was associated with a lower risk of mortality and major cardiovascular events across various regions.
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Key Findings from the PURE Study
During a median follow-up of 9.3 years, a diet score of ≥5 points was associated with a lower risk of mortality, CVD, myocardial infarction, and stroke compared with a diet score of ≤1 points. Similar results were found in independent studies of vascular patients, with a higher diet score being associated with lower mortality and CVD.
Global Applicability of the Healthy Diet Score
The PURE study also found that a higher diet score was associated with a significantly lower risk of death or CVD in regions with lower gross national incomes. This suggests that a diet comprised of higher amounts of fruit, vegetables, nuts, legumes, fish, and dairy foods is associated with lower risk of cardiovascular disease and mortality in all world regions, especially in lower income countries.
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