Women who followed a Mediterranean-style diet at midlife maintained their health and well-being past age 70, a large U.S. study suggests.
Researchers surveyed 10,670 women in the Nurses Health Study who were in their late 50s and early 60s about their diet and then asked the same women about their health an average of 15 years later.
"In summary, we found that greater quality of diet at midlife was strongly associated with increased odds of good health and well-being among individuals surviving to older ages," epidemiologist Cécilia Samieri of the French National Institute of Health and her co-authors concluded in Monday's online Annals of Internal Medicine.
"Maintaining physical, cognitive, and mental health with aging may provide a more powerful incentive for dietary change than simply prolonging life or avoiding any single chronic disease."
The healthy diet patterns focused on plant foods, whole grains, and fish with moderate intake of alcohol and lower intake of red and processed meats.
The study shows how following a healthy diet closely can improve the quality of aging.
"What people are interested in is avoiding any kind of disease or impairment with aging," said Samieri, who completed the study as a postdoctoral researcher at Harvard University in Boston.
The researchers separated "healthy" from "usual" aging based on assessments of mental, physical and cognitive function. Those in the healthy group were also free of chronic diseases, such as cancer, heart disease, stroke, Type 2 diabetes, kidney failure, Parkinson's disease and multiple sclerosis.
Population studies have also found associations between diet quality and lower risk of major coronary disease, Type 2 diabetes and cancer, the researchers said.
Carol Greenwood, a nutrition professor at the University of Toronto, liked how the researchers looked at healthy diet as a whole. The focus should be on what the plate looks like rather than individual foods, she believes.
"Freedom 55 really means being healthy in your 50s so you can enjoy yourself in your 70s," said Greenwood, who is also a scientist at Baycrest in Toronto, where she studies diet and cognition in older adults.
The Mediterranean diet is thought to work by protecting our blood vessels that deliver nutrients to the brain, decreasing inflammation and oxidative stress, said Greenwood.
Participants' diets were assessed twice in the study, including in midlife. The researchers carefully controlled for physical activity, body mass index and smoking in their analysis but other unmeasured factors were also involved.
The women were mainly white health-care professionals and the results may not apply to other demographic groups.
The study was funded by the U.S. National Cancer Institute and U.S. National Institutes of Health.