Nutrition 2024: Study correlates healthy midlife diet and better life quality in old age

04 Jul 2024 --- A new study confirms the hypothesis that following a healthy diet during midlife correlates with a better quality of life during old age. Conducted by researchers from Harvard TH Chan Public School of Health, the research team presented the findings at Nutrition 2024, the annual meeting of the American Society for Nutrition in Chicago, US. 

“People who adhered to healthy dietary patterns in midlife, especially those rich in fruits, vegetables, whole grains and healthy fats, were significantly more likely to achieve healthy aging,” says Anne-Julie Tessier, Ph.D., a postdoctoral fellow at Harvard TH Chan School of Public Health and presenter of the abstract. “This suggests that what you eat in midlife can play a big role in how well you age.”

The study delves into the link between good nutrition and healthy aging, defined as the absence of disease but the ability to live independently and enjoy a good quality of life while growing older. It also found that fewer than one in 10 people could live disease-free and maintain good physical, cognitive and mental health from age 70 onward. 

Keeping tabs on aging healthily
Statistical data from approximately 106,000 people at a minimum age of 39 years and older were collected. The participants submitted information about their diets via questionnaires every four years, going back to 1986. Nearly half of the study participants died as of 2016, and only 9.2% survived to age 70 or older while maintaining freedom from chronic diseases and good physical, cognitive and mental health.

“A finding that stood out was the association between the Planetary Health Diet and healthy aging,” says Tessier. “This diet is based on the EAT-Lancet Commission’s report, which emphasizes fruits, vegetables, whole grains, plant proteins and healthy fats from sustainable sources.”

“The fact that it emerged as one of the leading dietary patterns associated with healthy aging is particularly interesting because it supports that we can eat a diet that may benefit both our health and the planet.”Researchers from Harvard TH Chan Public School of Health presented their latest findings about the link between a healthy diet and healthy aging at Nutrition 2024.

The researchers compared the rates of healthy aging in people with the highest percentages of adhering to healthy dietary patterns defined by previous scientific studies. 

Strong correlations were also found for the empirical dietary index for hyperinsulinemia diet (associated with a 78% greater likelihood of healthy aging), planetary health diet (68%), alternative Mediterranean diet (67%), dietary approaches to stop hypertension (DASH) diet (66%), the Mediterranean-DASH intervention for neurodegenerative delay (MIND) diet (59%) and empirical dietary inflammatory pattern (58%). A more modest association was found for the healthful plant-based diet (43%).

The strongest correlation was seen with the Alternative Healthy Eating Index, which reflects close adherence to the Dietary Guidelines for Americans. Participants in the top quintile for this dietary pattern were 84% more likely to achieve healthy aging than those in the bottom quintile.

Merging the mental and physical 
The research revealed that people following a healthy diet from their 40s onward were 43–84% more likely to function well physically and mentally at age 70 than those who did not.

The researchers note that higher intakes of fruits, vegetables, whole grains, unsaturated fats, nuts, legumes and low-fat dairy are associated with better odds of aging healthily. On the other hand, higher intakes of trans fat, sodium, total meats, red and processed meats are associated with diminished odds of healthy aging.

“Traditionally, research and derived dietary guidelines have focused on preventing chronic diseases like heart disease. Our study provides evidence for dietary recommendations to consider not only disease prevention but also promoting overall healthy aging as a long-term goal,” says Tessier.

The connection between diet and healthy aging remained strong even when the researchers accounted for physical activity and other factors known to impact health. Tessier noted that each of the healthy dietary patterns was linked with healthy aging as a whole and with the individual components of healthy aging, such as physical health, cognitive functioning and mental health.

Tessier recommends that future research shed light on the potential impacts of switching to healthier dietary patterns later in life.

The current study suggests that a healthy diet in midlife could increase the chance of achieving healthy aging. Meanwhile, the abstracts presented at Nutrition 2024 are evaluated and selected by a committee but have not generally undergone the same peer review process required for publication in a scientific journal.

By Inga de Jong