Eating a healthy diet and exercising in middle age may make you less likely to have dementia decades later.

That's the message from researchers at the 10th International Conference on Alzheimer's Disease and Related Disorders, being held this week in Madrid, Spain.

Studies presented at the conference highlight the potential brain benefits of eating healthfully and being physically active. The bottom line: The sooner you get started, the better.

Two of the studies stemmed from the Cardiovascular Risk Factors, Aging, and Incidence of Dementia (CAIDE) project, which included more than 1,400 adults in Finland. When they joined the study in middle age, participants took diet surveys and noted work-related and leisure-time physical activity.

20 Years Later

About 20 years later, those who were physically active in their free time and whose diets were rich in fish and polyunsaturated fats tended to have sharper minds and better memories than those who hadn't been active, or who had eaten a lot of saturated fat from milk products and spreads.

These patterns were even seen in people with the ApoE e4 gene, which is associated with higher risk of Alzheimer's disease, the most common type of dementia.

The diet study comes from researchers Marjo Laitinen, MSc, of Finland's University of Kuopio, and colleagues. The physical activity study was done by Suvi Rovio, MSc, of the Karolinska Institute in Stockholm, Sweden, and other researchers.

Their findings are echoed in two North American studies.

Canadian, U.S. Studies

In Canada, researchers studied more than 4,600 adults who were at least 64 years old. Over five years, 454 participants developed cognitive impairment that wasn't dementia.

Participants with the highest physical activity levels at the study's start were least likely to have developed the nondementia cognitive impairment.

Adjusting for age, sex, education level, and other risk factors didn't change the results, report Laura Middleton, MSc, and colleagues. Middleton works at Dalhousie University in Halifax, Nova Scotia.

Lastly, the long-term Bogalusa Heart Study -- done in Bogalusa, Ala. -- shows that even at a relatively young age, being in good health may help the brain.

Lifelong Process?

In that study, Tulane University neurology professor Benjamin Seltzer, MD, and colleagues checked data on 72 Bogalusa Heart Study participants who were 24-44 years old.

Participants took tests of mental skills such as memory and word recognition.

Older participants and those with higher blood levels of insulin (a hormone that controls blood sugar) scored worse on several of the tests.

"These findings emphasize the importance of maintaining cardiovascular health throughout the life span," write Seltzer and colleagues. They plan to study whether heart health in childhood influences cognitive function in middle age.

In short, taking care of your body may help preserve your brain.

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