1 / 9A 30-year study analysing eight popular diets has found that the Alternative Healthy Eating Index (AHEI) diet is the most effective in promoting healthy ageing into the 70s and beyond. (Image: Shutterstock)
2 / 9Conducted by researchers at Harvard T.H. Chan School of Public Health, the University of Copenhagen, and the University of Montreal, the study evaluated dietary data from over 105,000 middle-aged nurses and health professionals. Participants completed dietary questionnaires over three decades, which were then scored based on their adherence to eight different dietary patterns. (Image: Shutterstock)
3 / 9The AHEI diet, which emphasises higher intakes of vegetables, fruits, legumes, and nuts while limiting sugar-sweetened drinks, red and processed meats, salt, and trans fats, was found to provide slightly greater health benefits compared to the Planetary Health Diet Index, Mediterranean diet, and other plant-based diets. Some meat, fish, and dairy are allowed in the AHEI diet but in controlled amounts. (Image: Shutterstock)
4 / 9The study found that only 9.3% of participants (9,771 individuals) aged healthily—defined as reaching 70 without major chronic diseases like heart disease, diabetes, or cancer while maintaining good cognitive, physical, and mental health. (Image: Shutterstock)
5 / 9However, individuals whose diets most closely resembled the AHEI were 86% more likely to reach 70 in good health and more than twice as likely to reach 75 in good health compared to those whose diets least resembled the AHEI. (Image: Shutterstock)
6 / 9Dr. Marta Guasch-Ferré, co-corresponding author and associate professor at the University of Copenhagen, explained that the AHEI diet includes all necessary nutrients for a healthy life and was originally developed to prevent chronic diseases. She emphasised the importance of not just lifespan but “health span,” ensuring people remain physically, cognitively, and mentally independent as they age. (Image: Shutterstock)
7 / 9The second-best performing diet was the Planetary Health Diet Index, which prioritises plant-based eating while also considering environmental sustainability. However, the study found that adherence to any of the eight dietary patterns was associated with better ageing outcomes, as all of them emphasised higher intake of plant-based foods like vegetables, whole grains, nuts, and legumes over meat. (Image: Shutterstock)
8 / 9Guasch-Ferré noted that the AHEI diet’s inclusion of low to moderate amounts of healthy animal-based foods may be beneficial for older adults, particularly in maintaining bone health and preventing osteoporosis. However, she added that this might not be ideal for younger adults, who were not included in the study. (Image: Shutterstock)
9 / 9The study also highlighted that lower consumption of ultra-processed foods, which contain artificial ingredients, was linked to better ageing outcomes. This research was published in Nature Medicine. (Image: Shutterstock)
