Women with high physical fitness at
middle age were nearly 90 percent less likely to develop dementia decades
later, compared to women who were moderately fit, according to a study
published the March 14, 2018, online issue of Neurology, the medical journal of the American Academy of Neurology. The
study measured the women's cardiovascular fitness based on an exercise test.
When the highly fit women did develop dementia,
they developed the disease an average of 11 years later than women who
were moderately fit, or at age 90 instead of age 79.
"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 Hörder, Ph.D., of the University of Gothenburg in Gothenburg,
Sweden. "However, this study does not show cause and
effect between cardiovascular fitness and dementia,
it only shows an association. More research is
needed to see if improved fitness could have a positive effect on the risk of
dementia.... (Those fitter women might also be eating
better for instance.....) and also to look at when during a lifetime a
high fitness level is most important."
For the study, 191 women with an average age of
50 took a bicycle exercise
test until they were exhausted to measure their peak cardiovascular
capacity. The average peak workload was measured at 103 watts.
- A total of 40 women met the criteria for a high
fitness level, or 120 watts or higher.
- A total of 92 women were in the medium fitness
- 59 women were in the low fitness category, defined as a peak
workload of 80 watts or less, or having their exercise tests stopped because
of high blood pressure, chest pain or other cardiovascular problems.
Over the next 44 years, the women were tested for
dementia six times. During that time, 44 of the women developed dementia.
- 5 percent of the highly fit women developed dementia, compared to
- 25 percent of moderately fit women and
- 32 percent of the women with low fitness.
The highly fit women were 88 percent
less likely to develop dementia than the moderately fit women.
Among the women who had to stop the exercise test due to problems, 45
percent developed dementia decades later.
"This indicates that negative cardiovascular processes may be happening in
midlife that could increase the risk of dementia much later in life," Hörder
Limitations of the study include the relatively
small number of women involved, all of whom were from Sweden, so
the results may not be applicable to other populations, Hörder said. Also,
the women's fitness level was measured only once, so any changes in fitness over time were not captured.