Eight Diet Patterns Compared: Top Healthy-Eating-Index Group Has 1.86 Times the Odds of Healthy Ageing
In more than 100,000 people followed for up to 30 years, those who adhered best to plant-centred diets were more likely to age healthily.
Which diet comes closest to 'healthy ageing,' beyond just preventing disease? Researchers at Harvard T.H. Chan School of Public Health in the United States followed 105,015 participants in the Nurses' Health Study and the Health Professionals Follow-Up Study for up to 30 years and compared eight dietary patterns and ultra-processed food intake. Healthy ageing was defined as living to age 70 free of major chronic diseases while having good cognitive, physical and mental health.
During follow-up, 9,771 people (9.3%) met this definition. For all eight patterns, higher adherence was associated with higher odds of healthy ageing, and the odds ratios comparing the top and bottom fifths ranged from 1.45 for the healthful plant-based diet to 1.86 for the Alternative Healthy Eating Index (AHEI). When the reference age was raised to 75, the odds ratio for AHEI rose to 2.24.
What people ate more and less of
Greater intake of fruits, vegetables, whole grains, unsaturated fats, nuts, legumes and low-fat dairy was associated with healthy ageing, while trans fats, sodium, sugar-sweetened beverages, red meat and processed meat went in the opposite direction. The researchers interpreted the results to mean that a diet centred on plant foods, with a moderate amount of healthy animal foods, may be advantageous for ageing overall.
However, the participants were health professionals, which limits generalising to the general population, and diet was measured by self-reported questionnaires. Because this is an observational study, it does not prove that any particular diet causes healthy ageing.
- 105,015 people in two U.S. cohorts, followed for up to 30 years
- For all 8 diet patterns, higher adherence meant higher odds of healthy ageing; AHEI odds ratio 1.86 (2.24 at reference age 75)
- Trans fats, sodium, sugar-sweetened beverages, red meat and processed meat were inversely associated
Limitations This is an observational study of a health-professional cohort. It does not prove causation, and the dietary data rely on self-reports.
Original research
- Tessier AJ, et al. · Harvard T.H. Chan School of Public Health. Optimal dietary patterns for healthy aging. Nature Medicine. DOI: 10.1038/s41591-025-03570-5
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