After a three-decade long study, American researchers say that food choices rival tobacco as a preventable ageing accelerator – and that women benefitted more than men from healthy diets.
They said olive oil and avocado lovers had 40% better physical function, outperforming even those who exercised regularly but skimped on unsaturated fats, and that interestingly, fast food and snacks were linked to better odds of surviving to age 70, possibly because of the social aspects of eating out – though they weren’t associated with better health overall.
For their study, which was published in Nature Medicine, the researchers had examined the association between long-term adherence to eight dietary patterns and the consumption of ultra-processed foods (UPF) with healthy ageing.
Their findings indicate that following a plant-based, nutrient-dense diet with moderate amounts of healthful animal-based food intake, including low-fat dairy, may significantly enhance healthy ageing.
Chronic disease
The number of older people in the US has increased, but 80% have one or more chronic diseases, creating significant health challenges.
The WHO now emphasises preserving function and preventing decline rather than treating diseases, while studies show that better diets help prevent type 2 diabetes, cardiovascular disease and early death.
Research also links diet to physical and cognitive health, as well as mental well-being, in the ageing population.
However, there is little understanding of how overall dietary patterns influence multiple aspects of healthy ageing.
Three decades of adherence
This study investigated the 30-year association between adherence to eight healthful dietary patterns, consumption of ultra-processed food (UPF), and healthy ageing in two large US cohorts, while also analysing differences by sex, ancestry, socioeconomic status, lifestyle factors, and individual food components.
Data came from the Nurses’ Health Study and the Health Professionals Follow-up Study, which have tracked lifestyle and health outcomes since 1986. Participants with major chronic diseases, missing dietary data, or implausible energy intake were excluded.
Dietary intake was assessed using a validated food frequency questionnaire (FFQ), yielding eight dietary pattern scores: the Alternative Healthy Eating Index (AHEI), Dietary Approaches to Stop Hypertension (DASH), Alternative Mediterranean Diet (aMED), Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND), Planetary Health Diet Index (PHDI), Healthful Plant-based Diet Index (hPDI), reversed Empirical Dietary Index for Hyperinsulinemia (rEDIH), and reversed Empirical Inflammatory Dietary Pattern (rEDIP), along with ultra-processed food (UPF) consumption.
Healthy ageing was defined as reaching 70 without major chronic diseases and with good cognitive, physical, and mental health. Covariates like BMI, smoking, and physical activity were accounted for.
Findings
The study analysed data from 105 015 individuals (34 924 men and 70 091 women). Over 30 years, 9.3% (9 771 people) exhibited healthy ageing. Among all participants, 37.9% lived to at least 70, 22.8% were free from 11 chronic conditions, 33.9% retained cognitive function, 28.1% preserved physical function, and 26.5% maintained mental health.
Those following healthier dietary patterns generally had higher socioeconomic status, more physical activity, lower BMI, and lower rates of past depression.
Strongest associations with healthy ageing were found in AHEI, followed by DASH, MIND, hPDI and PHDI. AHEI showed the strongest effect, while hPDI showed the weakest – possibly due to its stricter plant-food focus without prioritising quality (e.g, whole vs refined grains). Adherence to these diets increased healthy ageing likelihood by 45% to 86%.
Cognitive health benefited most from PHDI; physical function from AHEI; mental health from AHEI; and chronic disease prevention from rEDIH. PHDI also had the greatest impact on survival to age 70. UPF consumption was associated with a 32% lower odds of healthy ageing.
Greater intake of fruits, vegetables, whole grains, nuts, legumes, unsaturated fats (e.g, olive oil), and healthy fats was linked to better ageing outcomes. Processed meats, trans fats, and sodium were linked to worse outcomes. Benefits were strongest among women, smokers, individuals with lower socioeconomic status, and those with less physical activity.
Conclusions
The study found that healthier midlife dietary patterns were linked to better odds of healthy ageing over 30 years. AHEI was most strongly associated with overall healthy ageing, especially mental and physical function. With stricter definitions (e.g, survival to 75), AHEI’s impact was even greater.
PHDI, which integrates sustainability and health, showed the strongest effects on cognitive health and survival to age 70. rEDIH was most effective in chronic disease prevention. Diets rich in plant foods and healthy fats, and low in processed foods and red meat, were consistently associated with improved ageing outcomes.
Study limitations include lack of diversity, as most participants were white health professionals.
Study details
Optimal dietary patterns for healthy ageing
Anne-Julie Tessier, Fenglei Wang, Andres Ardisson Korat et al.
Published in Nature Medicine on 24 March 2025
Abstract
As the global population ages, it is critical to identify diets that, beyond preventing non-communicable diseases, optimally promote healthy ageing. Here, using longitudinal questionnaire data from the Nurses’ Health Study (1986–2016) and the Health Professionals Follow-Up Study (1986–2016), we examined the association of long-term adherence to eight dietary patterns and ultra-processed food consumption with healthy ageing, as assessed according to measures of cognitive, physical and mental health, as well as living to 70 years of age free of chronic diseases. After up to 30 years of follow-up, 9,771 (9.3%) of 105,015 participants (66% women, mean age = 53 years (s.d. = 8)) achieved healthy ageing. For each dietary pattern, higher adherence was associated with greater odds of healthy ageing and its domains. The odds ratios for the highest quintile versus the lowest ranged from 1.45 (95% confidence interval (CI) = 1.35–1.57; healthful plant-based diet) to 1.86 (95% CI = 1.71–2.01; Alternative Healthy Eating Index). When the age threshold for healthy ageing was shifted to 75 years, the Alternative Healthy Eating Index diet showed the strongest association with healthy ageing, with an odds ratio of 2.24 (95% CI = 2.01–2.50). Higher intakes of fruits, vegetables, whole grains, unsaturated fats, nuts, legumes and low-fat dairy products were linked to greater odds of healthy ageing, whereas higher intakes of trans fats, sodium, sugary beverages and red or processed meats (or both) were inversely associated. Our findings suggest that dietary patterns rich in plant-based foods, with moderate inclusion of healthy animal-based foods, may enhance overall healthy ageing, guiding future dietary guidelines.
Nature Medicine article – Optimal dietary patterns for healthy ageing (Open access)
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