Healthy Eating in Midlife Linked to Longevity and Well-Being
Maintaining a Balanced Diet Promotes Healthy Aging
A new study conducted by researchers from Harvard T.H. Chan School of Public Health, the University of Copenhagen, and the University of Montreal has found that a nutritious diet in midlife significantly increases the chances of aging healthily. Healthy aging, in this context, refers to reaching the age of 70 free from major chronic illnesses while maintaining cognitive, physical, and mental well-being.
This groundbreaking study is one of the first to examine multiple dietary patterns in midlife and their overall impact on aging. The findings, published in Nature Medicine on March 24, highlight the importance of dietary choices for long-term health and quality of life.
The Link Between Diet and Healthy Aging
According to Professor Frank Hu, co-corresponding author of the study and Chair of the Department of Nutrition at Harvard Chan School, previous research has focused on specific diseases or lifespan. However, this study takes a broader approach, examining how diet influences a person’s ability to live independently and maintain a high quality of life as they age.
The study analysed data from over 105,000 participants aged 39 to 69, gathered from the Nurses’ Health Study and the Health Professionals Follow-Up Study over three decades. Participants completed regular dietary questionnaires, which researchers used to evaluate adherence to eight recognised dietary patterns.
Dietary Patterns Analysed in the Study
Researchers assessed how well participants followed these eight dietary patterns:
Alternative Healthy Eating Index (AHEI) – Designed to prevent chronic diseases by encouraging a diet rich in fruits, vegetables, whole grains, nuts, legumes, and healthy fats.
Alternative Mediterranean Index (aMED) – A Mediterranean-based diet high in plant-based foods, olive oil, and fish.
Dietary Approaches to Stop Hypertension (DASH) – A diet focused on reducing high blood pressure with fruits, vegetables, whole grains, and low-fat dairy.
Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) – A combination of the Mediterranean and DASH diets aimed at brain health.
Healthful Plant-Based Diet Index (hPDI) – Emphasising plant-based foods while minimising unhealthy plant-based options like sugary foods.
Planetary Health Diet Index (PHDI) – A diet considering both human and environmental health by prioritising plant-based nutrition.
Empirically Inflammatory Dietary Pattern (EDIP) – A dietary pattern measuring the inflammatory potential of foods.
Empirical Dietary Index for Hyperinsulinemia (EDIH) – Assessing dietary impact on insulin levels.
Each of these diets encourages a high intake of fruits, vegetables, whole grains, nuts, legumes, and healthy fats, with some allowing moderate consumption of healthy animal-based foods such as fish and dairy.
Key Findings: The Impact of a Healthy Diet
The study found that 9.3% (9,771 participants) aged healthily. Following any of the healthy dietary patterns significantly increased the chances of healthy aging, including cognitive, physical, and mental well-being.
Among these dietary patterns, the Alternative Healthy Eating Index (AHEI) was particularly effective:
Participants with the highest adherence to the AHEI had an 86% greater likelihood of reaching age 70 in good health compared to those with the lowest adherence.
They were also 2.2 times more likely to maintain good health at 75.
Another leading diet was the Planetary Health Diet Index (PHDI), which not only supports individual health but also prioritises sustainability by reducing animal-based food consumption.
The Harmful Effects of Ultra-Processed Foods
The study also highlighted the negative impact of ultra-processed foods, which are industrially manufactured and often contain artificial ingredients, added sugars, unhealthy fats, and high sodium levels. The consumption of these foods, especially processed meats and sugary beverages (both regular and diet versions), was associated with lower chances of healthy aging.
Expert Insights and Public Health Implications
Professor Marta Guasch-Ferré, co-corresponding author and associate professor at the University of Copenhagen, emphasised that maintaining independence and good health in old age is a priority for both individuals and public health initiatives.
“Our findings suggest that dietary patterns rich in plant-based foods, with moderate inclusion of healthy animal-based foods, may promote overall healthy aging and help shape future dietary guidelines,” she said.
Meanwhile, lead author Anne-Julie Tessier from the University of Montreal noted that there is no single ideal diet. “Healthy diets can be adapted to fit individual needs and preferences, allowing flexibility while still promoting longevity and well-being.”
Study Limitations and Future Research
Although the study provides valuable insights, it had some limitations:
The study population consisted entirely of health professionals, which may not fully represent the general population.
Further research is needed to assess whether these findings apply across diverse socioeconomic and ethnic groups.
The researchers suggest that replicating the study among different populations could provide a more comprehensive understanding of the link between diet and healthy aging.
Funding and References
The study was supported by several organisations, including the National Institutes of Health, the Canadian Institutes of Health Research, the United States Department of Agriculture, and the Novo Nordisk Foundation.
For more details, refer to the full study: Optimal Dietary Patterns for Healthy Aging by Anne-Julie Tessier et al., published in Nature Medicine (March 24, 2025), DOI: 10.1038/s41591-025-03570-5.
Conclusion: The Power of a Healthy Diet
This study reinforces the importance of dietary choices in midlife for long-term well-being. A diet rich in whole, plant-based foods with moderate amounts of healthy animal-based foods can significantly improve the chances of aging healthily.
Avoiding ultra-processed foods and following a balanced, nutritious diet can contribute to a longer, healthier, and more independent life.