A groundbreaking study from Harvard T.H. Chan School of Public Health, in collaboration with the University of Copenhagen and the University of Montreal, reveals that diets rich in plant-based foods, moderate in healthy animal products, and low in ultra-processed foods are most linked to healthy aging. The research, published in Nature Medicine, followed over 105,000 adults for 30 years, providing new insights into the dietary habits that promote longevity and good health.
The study defined “healthy aging” as living to at least 70 years old without major chronic diseases and maintaining good cognitive, physical, and mental health. Key findings suggest that there’s no one-size-fits-all approach to diet, as various dietary patterns all contributed to healthy aging, but plant-rich diets and minimal ultra-processed foods showed the strongest benefits.
Study Overview and Findings
Researchers examined midlife diets from participants of the Nurses’ Health Study and the Health Professionals Follow-Up Study. Participants, aged 39 to 69, completed dietary questionnaires regularly, and the researchers evaluated eight distinct dietary patterns, including:
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Alternative Healthy Eating Index (AHEI)
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Mediterranean Diet Index (aMED)
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DASH Diet (Dietary Approaches to Stop Hypertension)
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MIND Diet (Mediterranean-DASH Intervention for Neurodegenerative Delay)
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Healthful Plant-Based Diet Index (hPDI)
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Planetary Health Diet Index (PHDI)
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Empirically Inflammatory Dietary Pattern (EDIP)
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Empirical Dietary Index for Hyperinsulinemia (EDIH)
Each of these diets promoted high intake of fruits, vegetables, whole grains, healthy fats, nuts, and legumes, with varying degrees of inclusion of healthy animal-based foods like fish and dairy.
Key Results on Healthy Aging
The study found that 9.3% of participants (9,771 individuals) aged healthily. Following any of the healthy diets was linked to better cognitive, physical, and mental health during aging. Among the most beneficial diets, the AHEI was particularly notable. Participants in the highest AHEI quintile were 86% more likely to age healthily at 70, and 2.2 times more likely at 75, compared to those in the lowest quintile.
Another strong diet was the PHDI, which emphasizes plant-based foods while minimizing animal-based foods for better human and environmental health.
The Role of Ultra-Processed Foods
The study also highlighted the detrimental effects of ultra-processed foods, especially processed meats, sugary drinks, and diet beverages, which were associated with lower chances of healthy aging. Limiting these foods, alongside increasing plant-based food intake, was key to better health outcomes in aging.
Implications for Public Health
Lead author Anne-Julie Tessier emphasized the importance of adapting dietary guidelines to include a variety of healthy diets suited to individual needs and preferences. The study suggests that plant-based diets, with moderate inclusion of healthy animal-based foods, may promote healthy aging and should inform future dietary recommendations.
However, the study’s limitations, including the homogeneous study population of health professionals, suggest the need for further research involving diverse socioeconomic groups and populations.
This study provides crucial evidence supporting the link between healthy, plant-focused diets and longevity, encouraging further exploration into dietary patterns that promote healthy aging.
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