• Posted February 25, 2026

Eating Healthy In Middle Age Can Lower Risk of Brain Decline, Study Finds

What’s on your plate today can affect your brain aging as a senior, a new study says.

Middle-aged people who eat healthy have a lower risk of brain decline in old age, researchers reported Feb. 23 in JAMA Neurology.

The heart-healthy Dietary Approaches to Stop Hypertension (DASH) diet provided the best protection for brain health, but results showed that eating patterns aimed at lowering blood sugar or inflammation also lowered risk of cognitive decline.

“Higher intake of vegetables, fish, and moderate wine consumption contributed to the observed associations, whereas red and processed meats, fried potatoes, and sugary beverages were associated with poorer cognition,” concluded the research team led by senior researcher Dr. Kjetil Bjornevik, an assistant professor of epidemiology and nutrition at Harvard T.H. Chan School of Public Health.

“These findings suggest that a healthy diet may benefit cognitive health in future life,” the team wrote.

For the new study, researchers pooled data from three major studies tracking the lifetime health of nurses and health professionals. More than 159,000 people were included in this analysis.

The research team scored each participant on how well their reported diet conformed to six different healthy eating patterns, including the DASH diet, the Healthful Plant-Based Diet Index, the Planetary Health Diet Index and the Alternate Healthy Eating Index 2010.

Those diet scores were then compared to how well a person’s brain functioned in old age, as reported by each participant.

Results showed that the DASH diet protected brain health best.

People whose eating pattern followed the DASH diet most closely had a 41% lower risk of brain decline, compared with those whose eating least followed DASH.

In particular, a higher DASH diet score at ages 45 to 54 showed the strongest association with healthy brain aging, researchers found.

“When you talk about people in this age cohort, it's almost a foregone conclusion that they think, ‘Well, as you get older, you lose your memory, you don't think as quickly, you get brain fog, and there's nothing you can do about it because it comes with age,’ ” said Stephanie Schiff, a registered dietitian and nutritionist at Northwell Health in Huntington, New York.

“So it's really exciting to see that there's this study out of Harvard that says, ‘Wait a second, if you eat the proper way, if you follow a DASH diet, then there are actually ways that you can improve your memory, your cognitive function, your attention, your language, your executive function,’ ” added Schiff, who was not involved in the study.

Other healthy diets also lowered the risk of brain decline by 24%, to 11%, the study found.

Vegetables, fruits, fish, wine, tea and salad dressings all were associated with better brain aging, researchers said. Fried potatoes, red and processed meats, eggs, sugary drinks and sweet treats were tied to worse brain aging.

Schiff wasn’t surprised that the DASH diet provided great brain benefits.

“There can only be benefits from following the DASH diet, which is a heart-healthy diet. The reason it's great is because by keeping your heart healthy, you're actually keeping your brain healthy,” she said.

The diet’s emphasis on lowering blood pressure likely explains much of its benefit for brain aging, Schiff said.

High blood pressure damages blood vessels, including those that feed the brain, Schiff said.

“Once you don't have the proper amount of blood going to your brain, then you can have damage there. You don't have enough oxygen, there will be damage to our brain cells, and that can lead to a decrease in cognition, a decrease in memory and potentially an increased risk of Alzheimer's disease,” Schiff said.

More information

The University of Washington has more on healthy brain aging.

SOURCES: JAMA Neurology, Feb. 23, 2026; Stephanie Schiff, registered dietitian and nutritionist, Northwell Health, Huntington, New York