A diet rich in plant-based foods and low in ultra-processed products may boost longevity. It also enhances overall well-being, which is key to healthy aging. This is according to a new study by researchers at Harvard T.H. Chan School of Public Health, the University of Copenhagen, and the University of Montreal.
The study, published in Nature Medicine, suggests that midlife dietary choices influence the likelihood of reaching 70 free from major chronic diseases. These choices help maintain cognitive, physical, and mental health.
The Link Between Diet and Healthy Aging
Researchers analyzed data from the Nurses’ Health Study. They also examined the Health Professionals Follow-Up Study, which tracked the diets and health outcomes of over 105,000 participants. These participants were aged 39-69 and were followed for 30 years. Participants’ diets were scored based on adherence to eight dietary patterns:
- Alternative Healthy Eating Index (AHEI)
- Alternative Mediterranean Index (aMED)
- Dietary Approaches to Stop Hypertension (DASH)
- Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND)
- Healthful Plant-Based Diet (hPDI)
- Planetary Health Diet Index (PHDI)
- Empirically Inflammatory Dietary Pattern (EDIP)
- Empirical Dietary Index for Hyperinsulinemia (EDIH)
Each diet emphasizes fruits, vegetables, whole grains, unsaturated fats, nuts, and legumes. Some also allow moderate intake of healthy animal-based foods such as fish and dairy. Researchers also tracked participants’ consumption of ultra-processed foods, which often contain artificial ingredients, added sugars, sodium, and unhealthy fats.
BEST DIETS FOR LONGEVITY
Of the study participants, 9,771 (9.3%) aged healthfully. The AHEI diet showed the strongest link to healthy aging. Those with the highest adherence to AHEI had an 86% higher chance of reaching 70 in good health. They also had a 2.2-fold increased likelihood of reaching 75 in optimal condition.
The PHDI diet, which prioritizes plant-based foods while considering environmental sustainability, also ranked highly. Conversely, higher intake of ultra-processed foods—especially processed meats and sugary drinks—was associated with poorer aging outcomes.
WHY DIET MATTERS FOR AGING
Lead researcher Frank Hu, a professor at Harvard Chan School, highlighted the importance of diet in maintaining independence and quality of life in older age.
“Our study goes beyond longevity to examine how diet affects people’s ability to live independently and enjoy a good quality of life as they age,” he said.
Marta Guasch-Ferré, a co-author from the University of Copenhagen, emphasized that no single diet fits everyone. “Healthy diets can be adapted to fit individual needs and preferences,” she noted.
STUDY LIMITATIONS AND FUTURE RESEARCH
The study primarily included health professionals, which may limit its generalizability to other populations. Researchers suggest further studies on diverse groups with different socioeconomic backgrounds.
This research was supported by grants from the National Institutes of Health, the Canadian Institutes of Health Research, and the Novo Nordisk Foundation.
Switching to a plant-rich diet with minimal ultra-processed foods could enhance longevity and quality of life. While no single diet guarantees healthy aging, emphasizing whole, nutritious foods appears to be a key factor in maintaining long-term well-being.
