A recently published study of 191 women found those who were highly fit in middle age decreased their risk for dementia by 88 percent compared to those who were moderately fit.
“Women are at greater risk of developing dementia, especially Alzheimer’s-related dementia, than men are,” said Dr. Diana Kerwin, chief of geriatrics with Texas Health Dallas. “So to have something where we've got more data on women is very helpful.”
After initial tests in middle age (ages 38 to 60), researchers in Sweden followed women considered at high physical fitness for more than 30 years. Those who could ride an exercise bike at a fast rate for six minutes in the initial test had a much lower rate of dementia than those who could not complete the workout – even though both groups lived as long. They also tended to have lower blood pressure and fewer strokes.
"For anybody who’s worried about their brain as they get older, this really underscores what we’ve been looking at in research on how can people prevent dementia, what can we tell them to do,” Kerwin said.
On importance of blood pressure: The brain’s very sensitive to changes in our blood pressure. If you’re even having a slight elevation in blood pressure, it can put pressure on those really small tiny blood vessels in the brain. They start to close off, and although you won’t have a full-blown stroke, over the years we can see these build up on your brain MRIs and that can be correlated with memory loss.
On high level exercise versus moderate: We think high exercise or really moderate exercise to start with is about 30 minutes of cardiovascular exercise, where you’re getting up to 75 percent of your target heart rate, at least five days a week, so that’s 150 minutes of exercise a week. For some people, depending on what their other illnesses might be, you might have to try to get that aerobic exercise in a pool or through a good walk or a run. It’s not weightlifting. This is more about getting your heart rate up.
On why exercise can be effective against dementia: It does lower blood pressure automatically. It lowers inflammation, and inflammation is something of great concern as far as it might be causative for dementia and for Alzheimer’s in particular. So exercise lowers that inflammation in the body, lowers your glucose, your sugar levels, lowers your blood pressure and cholesterol. And for the brain itself, there are short-term and long-term benefits of exercise, including increased blood flow to the brain tissue. The brain’s getting more nutrients and things it needs.