Physically fit middle age women 90% less likely to develop dementia

According to a Swedish study posted in the American Academy of Neurology, 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.

| March 15, 2018 | TRAINING

Age group women head to the start of the Ironman World Championship in Kailua-Kona, Hawaii in 2017.

Age group women head to the start of the Ironman World Championship in Kailua-Kona, Hawaii in 2017.

Photo >Kevin Mackinnon

A study done in Sweden offers up some exciting news for fit, middle-aged women. The study, published in the March 14 issue of Neurology, the medical journal of the American Academy of Neurology, found that women who were considered to be at a "high fitness level" were about 90 percent less likely to develop dementia compared to women who were considered "moderately fit."

The study also found that when highly fit women did get dementia, they developed the disease, on average, 11 years later then women who were moderately fit - at age 90 versus 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, PhD, 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 and also to look at when during a lifetime a high fitness level is most important."

The study was done with 191 women with an average age of 50. They took a bicycle test until exhaustion to measure their peak cardiovascular capacity. The average peak workload was 103 watts. Those with an average of over 120 watts were considered to have a "high fitness level" - 40 women met that criteria. There were 92 women who were deemed in the "medium fitness category," while 59 women were considered to be in the "low fitness category" with a peak workload of 80 watts or less. (Some in that group had "their exercise tests stopped because of high blood pressure, chest pain or other cardiovascular problems.")

The women were tested over the next 44 years and, during that period, 44 women developed dementia. Only "five 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," according to the report. That meant the highly fit women were "88 percent less likely to develop dementia than the moderately fit women."

Another interesting finding from the study was that 45 percent of the women who had to stop the exercise test 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 says.

Hörder points out that some of the 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." There was also no examination of the women's fitness after the initial test, so there's no way to know if changes in fitness affected the results.

Regardless of the limitations, it's hardly bad news for most triathletes, many of whom would likely fit in that "high fitness level" group.