Need more incentive to work out? Women who had high levels of physical fitness in middle age were almost 90 percent less likely to develop dementia years later than women who were moderately fit. And if women who were very fit did develop dementia, they were likely to get it, on average, 11 years later than those who were moderately fit, or at age 90 instead of age 79.
Those are the findings from researchers at the university of Gothenburg in Sweden, who followed 191 Swedish women who were part of a large and ongoing study. The women were, on average, about 50 years old at the start. At that time, all completed a physical fitness test, in which they rode on stationary bikes until they were exhausted so that the researchers could assess their cardiovascular fitness.
The women were grouped into three categories: low level of fitness, medium level of fitness, or high level of fitness. Forty women were grouped into the high fitness level, riding their bikes at an average peak workload of 120 watts or higher (about 17 miles per hours); 92 were in the medium fitness range; and 59 were in the low fitness category (80 watts or less).
The study was relatively small, but it lasted a very long time compared to any similar studies — up to 44 years, when some of the women were in their 90s. By the end of the study, in 2012, many of the women had died.
During that time, 44 of the women developed Alzheimer’s disease or other forms of dementia. The researchers found that 32 percent of those in the low-fitness group developed dementia, compared to 25 percent of those in the medium-fitness group did. But only 5 percent of the high-fitness group developed dementia.
“These findings are exciting because it’s possible that improving people’s cardiovascular fitness in middle age could delay or even prevent them from developing dementia,” said study author Helena Horder.
She noted, however, that the study does not prove cause and effect. Other factors, such as diet, disease, genes and lifestyle, may have played a role. “More research is needed to see if improved fitness could have a positive effect on the risk of dementia and also to look at when during a lifetime a high fitness level is most important,” Dr. Horder said. It’s also unknown how many years of an active lifestyle it takes to actually have an impact.
Other studies have found similar links between physical fitness and dementia prevention. An earlier study in Swedish men, for example, found that those who were least physically fit at age 18 were more likely to develop dementia decades later. And numerous population studies have linked physical activity to preservation of memory and thinking skills and a decreased risk of dementia.
The researchers speculate that physical activity is known to be good for heart and blood vessel health, including blood vessels in the brain. Exercise also spurs the production of nerve growth factors, particularly in the hippocampus, a part of the brain critical for memory and where physical activity is known to boost new nerve cell growth.
In an editorial accompany the study, the writers conclude that “consistent evidence has suggested that interventions to prevent or treat cardiovascular disease may also improve brain health. What is good for the heart really does seem to be good for the brain also.”
By www.ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Marc Flajolet, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Sources: Helena Horder, PhD, Lena Johansson, PhD, XinXin Gui, MD, PhD, et al: “Midlife Cardiovascular Fitness and Dementia: A 44-year Longitudinal Population Study in Women.” Neurology, Vol. 90, March 2018
Nicole L. Spartano, PhD, and Tila Ngandu, MD, PhD: “Fitness and Dementia Risk Further Evidence of the Heart-Brain Connection.” Neurology Vol. 90, March 2018