What you eat in your 40s, 50s and 60s may affect how healthy you are at age 70.

Adults who stick to diets rich in plant-based foods, and eat fewer ultra-processed foods, in those middle decades of their lives, have a higher likelihood of reaching their 70th birthday free of major chronic disease, a recently published study has found.

The 30-year study, which followed the eating habits of more than 100,000 middle-aged adults, found that diets with comparatively higher amounts of plant-based foods — fruits, vegetables, whole grains, unsaturated fats, nuts and beans — were associated with a higher likelihood of healthy aging.

“This suggests what you eat in midlife can play a big role in how well you age,” said Anne-Julie Tessier, an assistant professor of nutrition at the University of Montreal and the lead author of the observational study, which was published in Nature Medicine.

The team of researchers from the Harvard T.H. Chan School of Public Health, University of Copenhagen and University of Montreal defined “healthy aging” as living to age 70 free of chronic disease such as diabetes and congestive heart failure, with positive marks on measures of cognitive, physical and mental health. In the study, 9,771 of the participants achieved healthy aging.

Most older adults have at least one chronic health condition. Previous studies have found diets that emphasize plants-based foods, and less red or processed meat, can lower the risk of cardiovascular disease and all-cause mortality. But, in this study, researchers set out to understand if these dietary guidelines could also enhance the quality of someone’s life in old age.

The facts

• The researchers examined the long-term, self-reported dietary patterns of 105,015 middle-aged U.S.

health professionals from 1986 to 2010 and then evaluated them for markers of healthy aging in 2016.

• Every four years, participants reported how often they ate more than 130 different foods. The researchers then measured how closely each person adhered to eight healthy diets, such as the Mediterranean diet, which prioritizes fruits, vegetables and olive oil.

• A higher adherence to any of the eight dietary patterns was associated with greater odds of healthy aging. These diets had comparatively more fruits, vegetables, whole grains and unsaturated fats, nuts, legumes and low-fat dairy.

• Diets higher in trans fats, sodium, sugary beverages and red or processed meat were associated with a lower likelihood of healthy aging. And participants who consumed the most ultra-processed foods had 32% lower odds of healthy aging.

• The positive associations of diet and aging were independent of other lifestyle factors, including physical activity, smoking and a person’s body mass index.

• Adherence to the Alternative Healthy Eating Index, a scoring system developed by nutrition experts at the Harvard T.H. Chan School of Public Health and one of the eight dietary patterns used in the study, showed the strongest associaHealth