Old age awaits everyone, but it hits some harder – and earlier – than others.
The way we age hinges partly on factors beyond our control, like genes or exposure to pollutants. But research suggests we can still influence the outcome with key behaviors, especially in how we sleep, exercise, and eat.
In a new 30-year study, researchers have taken an in-depth look at the links between eating habits and healthy aging, which they define as reaching age 70 without major chronic diseases or declines in cognitive, physical, or mental health.
The study is among the first to analyze multiple dietary patterns in middle age in relation to overall healthy aging, explains co-author Frank Hu, epidemiologist at Harvard University.
"Studies have previously investigated dietary patterns in the context of specific diseases or how long people live," Hu says. "Ours takes a multifaceted view, asking, 'How does diet impact people's ability to live independently and enjoy a good quality of life as they age?'"
Hu and his colleagues used longitudinal data from 105,000 adults between the ages of 39 and 69 (averaging 53 years old), collected between 1986 and 2016 as part of the Nurses' Health Study and the Health Professionals Follow-Up Study.
Subjects regularly completed dietary questionnaires over the 30-year period. The authors of the new study scored their eating habits by adherence to eight dietary patterns, seeking to learn which is most likely to promote healthy aging.
The eight dietary patterns are: the Alternative Healthy Eating Index (AHEI), the Alternative Mediterranean Index (aMED), the Dietary Approaches to Stop Hypertension (DASH), the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND), the healthful plant-based diet (hPDI), the Planetary Health Diet Index (PHDI), the empirically inflammatory dietary pattern (EDIP), and the empirical dietary index for hyperinsulinemia (EDIH).
All eight dietary patterns share some basic inclinations, the researchers note, such as a focus on whole, plant-based foods and healthy fats.
In addition to those eight patterns, the study examined subjects' consumption of ultra-processed foods – industrial creations often featuring many ingredients and excessive sugar, salt, and unhealthy fats.
The study found 9,771 participants met their definition of healthy aging, representing 9.3 percent of the sample population.
All eight dietary patterns were associated with healthy aging, the study found, so adhering to any one of them raised a person's odds of staying spry at 70.
This suggests the solution isn't simple, the researchers note, and no single diet is best for everyone. That said, one contender did stand out.
The best diet overall for healthy aging is the AHEI, according to the findings. It's similar to the older Healthy Eating Index, the researchers explain, but more oriented toward preventing chronic disease.
Subjects in the top quintile for the AHEI were 86 percent more likely to achieve healthy aging at 70 than those in the lowest quintile, the study found. If the cutoff age was 75, the top quintile was 2.24 times likelier to age healthily.
The AHEI emphasizes plant-based foods like fruits, vegetables, whole grains, nuts, and legumes, while minimizing red and processed meats, sugar-sweetened drinks, sodium, and refined grains.
"Since staying active and independent is a priority for both individuals and public health, research on healthy aging is essential," says co-author Marta Guasch-Ferré, Harvard nutritionist.
"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 adds.
While the AHEI showed the best results, it was closely followed by several others, including the aMED, DASH, PHDI, and MIND, the researchers report.
Along with the strongest link to overall healthy aging, the AHEI had the strongest link with maintaining physical function and mental health. The PHDI showed the strongest link with maintaining cognitive health and surviving to age 70.
Higher consumption of ultra-processed foods, on the other hand, was associated with a lower likelihood of healthy aging.
"Our findings also show that there is no one-size-fits-all diet. Healthy diets can be adapted to fit individual needs and preferences," says lead author Anne-Julie Tessier, nutritionist at the University of Montreal.
The study was published in Nature Medicine.