Your diet at 40 may affect how healthy you are at 70, study finds

If you eat well now, you may live better later. A diet rich in fruits and vegetables, whole grains and unsaturated fats in midlife can improve the chances of good mental, physical and cognitive health decades later, a new report shows.

A study presented at a major nutrition conference Tuesday builds on years of research that a daily diet filled with highly nutritious foods can reduce the risk of developing common chronic diseases and help maintain cognitive functioning in older age.

Harvard researchers analyzed 30 years of data on over 106,000 participants from the Nurses’ Health Study and the Health Professionals Follow-Up Study. The study included 70,467 women and 36,464 men. At the beginning of the study in 1986, the participants were at least 39 years old and free of chronic disease.

As part of the long-term study, the participants filled out an extensive food frequency questionnaire every four years, from 1986 to 2010, registered dietician Anne-Julie Tessier, lead author and research associate at Harvard School of Public Health, said.

The Harvard researchers tracked every participant’s personal diet over time to see how well they matched to eight highly nutritious dietary patterns.

The diets they compared the food questionnaires to included:

• The DASH diet, a meal plan intended to prevent or lower blood pressure by focusing on vegetables, fruits and whole grains. The eating plan, developed by the National Institutes of Health, is considered a flexible diet because it doesn’t eliminate any food groups and also helps with weight loss.
• The alternative healthy eating index (AHEI) — which closely adheres to to the U.S. dietary guidelines by encouraging more legumes, nuts and vegetables and lower amounts of red meat and processed meats. The research found the strongest correlation between the AHEI diet and healthier aging, Tessier said.
• The planetary health diet, an eating plan that minimizes animal products and emphasizes fruits, vegetables, whole grains, and healthy fats. It allows modest amounts of meat and dairy.

Overall, they found that a higher intake of fruits, vegetables, whole grains, unsaturated fats, nuts, legumes and low-fat dairy had greater odds of aging well. People whose diets consisted of more trans fats, sodium, red and processed meats had lower odds of healthy aging. 

What is ‘healthy aging’?

Based on the women and men’s self-reports in the database, the researchers interpreted “healthy aging” as surviving to at least age 70 and having good cognitive function, mental health, physical function — and being free of chronic diseases, such as diabetes, heart disease, stroke, kidney failure and most cancers.

After analyzing the 30-year data, the researchers found approximately half of the participants had died, with only 9% surviving to age 70 or older free of disease and unimpaired physical and cognitive health. 

However, the participants who most closely adhered to a healthy eating pattern were associated with 43% to 84% greater chances of aging well compared with those who did not.

What we eat now affects how we feel later

The new research has limitations. Similar to most nutrition research, the study is observational and based on self-reports. It doesn’t prove that following a nutritious dietary pattern closely will lead to longer life or healthier aging. It hasn’t yet been published in a journal but is currently under peer review, Tessier said.

Yet numerous studies have already demonstrated that diet and physical activity reduce the risk of all of these conditions and thus can increase the likelihood of “healthy aging,” Dr. R. Sean Morrison, chair for the Brookdale Department of Geriatrics and Palliative Medicine at Mount Sinai Hospital, said.

“It’s important to take into consideration that those who have healthy diets are more likely to exercise, more likely to live in socially advantaged neighborhoods, have access to support that others do not have, and are likely to have better access to health care,” said Morrison, who was not associated with the new study.

In fact, the researchers analyzed variables that could potentially influence the results, including BMI, ancestry, smoking status, alcohol intake, physical activity, medical and family history, socio-economic status, marital status and whether participants were living alone, Tessier noted. 

“We were surprised by the strength of the association between healthy eating patterns in midlife and a healthy later life, even after considering several other factors, like physical activity, that are also known to impact health,” she added.

Dr. Lawrence Appel, professor of medicine at the School of Medicine at John Hopkins University, who was not part of the research, said the study results support previous findings. Appel’s research focuses on preventing chronic diseases through nutritional approaches and was the lead author in the study that coined the DASH diet.

“This study joins a chorus of other studies that link healthy dietary behaviors earlier in life with better health, decades later,” he said.

For Mount Sinai’s Morrison, “the bottom line for healthy aging —which we have known for a long time — is to eat a healthy diet, exercise, avoid tobacco products, use sunscreen, get enough sleep, and participate in social activities.