What's Good For The Heart Is Good For The Brain

Credit: Katherine Streeter for NPR

Hoping to keep your mental edge as you get older? Look after your heart, a recent analysis suggests, and your brain will benefit, too.

A research team led by Hannah Gardener, an epidemiologist at the University of Miami, analyzed a subset of data from the Northern Manhattan Study, a large, ongoing study of risk factors for stroke among whites, blacks and Hispanics living in the Washington Heights neighborhood of New York City.

The scientists wanted to see how people in their 60s and 70s would do on repeated tests of memory and mental acuity six years later — and, specifically, what sort of subtle differences a heart-healthy lifestyle might make to the brain, beyond the prevention of strokes. Their findings appear in a recent issue of the Journal of the American Heart Association.

In this particular study, the researchers started with more than a thousand people who'd had their cardiovascular health assessed using measures that the American Heart Association has dubbed Life's Simple 7.

These seven factors known to benefit the heart and blood vessels include maintaining a normal body weight and good nutrition, not smoking, getting exercise regularly and keeping blood pressure, cholesterol and blood sugar levels under control.

To measure thinking skills, Gardener's team used a variety of tests of memory, judgment, the ability to plan, mental quickness and other sorts of problem solving.

The results were striking: Across all demographic groups, the people who had higher scores on the measures of cardiovascular health did better on the mental tests than those who scored low. And a check several years later of mental acuity showed that the apparent brain benefits of a heart-healthy life persisted. The higher a person's score on "Life's Simple 7" the better.

"When we looked at changes in their brain health over time they showed less decline in several of the brain-health domains — including better processing speed, better memory and better executive function," Gardener says.

Keeping the executive function abilities of the brain high — the set of mental skills that include organizational ability, time management and impulse control, for example — can be especially important as we get older, says Dr. Clinton Wright, a neurologist at the University of Miami and a co-author on the study.

While mild memory issues, such as forgetting a familiar name or place, can be annoying, it's the brain's executive functioning that governs our ability to manage life, Wright says.

Skills like "managing your checkbook, doing your shopping, preparing your taxes," fall into this category, he says, and if people have trouble doing these everyday chores as they get older, it can jeopardize their independence.

More research is needed to identify exactly how cardiovascular health helps protect the brain, the scientists say, and to figure out whether there are certain times in life when factors like diet or exercise are more influential in this regard.

It's likely that the same things that can damage blood vessels in the heart, "can also lead to damage to tiny little microvessels that are everywhere in the body," Wright says. "And if those microvessels are in the brain — that can cause damage that has an impact on cognitive function."

Whatever the biological mechanism, the message is clear, doctors say: Keep your heart as healthy as possible and you'll likely help your brain, too.