Exercise helps aging brain stay young

The Medicine Cabinet: Ask the Harvard Experts

Q: Over the last year, I sometimes forget things. I am 66 but I always have had a great memory. What can I do to avoid becoming more forgetful?

A: Most of us have had firsthand experience with memory lapses. We find ourselves flustered trying to recall a name during a conversation. We forget where we parked the car. We can’t recall items on the short grocery list we left back at home.

While memory lapses can occur at any age, they happen more often as we get older. And there is that fear they’re early signs of Alzheimer’s disease or some other type of dementia. But for the most part, our fleeting memory difficulties are from normal age-related changes in the brain. Our recall slows and it’s a bit harder to learn new things quickly.

Based on the results of many studies, staying physically active and exercising regularly in middle age and beyond might be the best thing you can do for you brain. It helps delay and perhaps even prevent decline in brain function.

Why should physical activity help keep you mentally sharp? The exact reason is not known. But it may be related to oxygen levels in the brain.

In a recent study, researchers identified 100 relatively healthy men and women ages 60 to 80 with varying levels of reported physical activity. For one week, the study participants wore an accelerometer to measure their amount of physical activity. Each of them also had their oxygen consumption measured during a maximal exercise test. Oxygen consumption during peak exercise is a standard way to assess cardiorespiratory fitness.

As expected, the people with higher fitness levels were the same ones that were more physically active during the week. They were also the same people who showed more positive oxygen related changes and MRI findings consistent with faster nerve processing in the brain. The study results were reported in PLOS One.

We don’t have an exact exercise prescription to guide how long and hard we should exercise. Based on the results of this study and many others, even low intensity activity for an hour a day appears to be much better for brain health than sitting on the couch.

Staying physically active with time scheduled daily for dedicated exercise is just one way path to better brain function. Here’s what else you can do:

Get enough sleep.

Find out if any of your medications cause memory problems.

Don’t smoke.

Limit alcohol intake.

Reduce stress.

Treat high blood pressure.

(Howard LeWine, M.D. is an internist at Brigham and Women’s Hospital and assistant professor at Harvard Medical School. For additional consumer health information, please visit www.health.harvard.edu.)