A research published in the journal Neurology revealed that middle-aged women with good physical fitness thanks to exercise, were at a much lower risk (over 80%) of developing neurodegenerative disease. The study also reveal that active women who did develop dementia did so much later in life than their more sedentary peers.
“These findings are exciting because it is possible that improving the cardiovascular capacity of people in middle age may delay or even prevent them from developing dementia,” said study author Helena Hörder of the University of Gothenburg, Sweden.
This is one of the most extensive studies in its field. It began in 1968, when the researchers measured the maximum cardiovascular capacity of 191 women with an average age of 50 years. The volunteers were asked to exercise on a bicycle until they were exhausted, while scientists recorded their maximum level.
Forty women achieved 120 watts or more, a number that put them in the high fitness category. Another 92 showed a medium-level physical condition (81 to 120 watts) and another 59 exhibited low-level physical fitness (80 watts or less). Some of those in the low-level fitness category were unable to complete the exercise because of chest pain, high blood pressure or cardiovascular problems.
The volunteers underwent dementia tests six times during the following 44 years. Within that time, 44 (23%) developed the disease. However, the probabilities of diagnosis varied widely according to the physical condition of each volunteer. Among all those who failed to complete the exercise test, 45% developed dementia. In contrast, among the women with better physical fitness, only 5% were diagnosed with the disease. Among those classified as having low fitness, 32% were diagnosed and, finally, among those with moderate fitness, 25% were diagnosed with the disease.
Moreover, the two very fit women who developed dementia did about 11 years later than those who were moderately fit. “This indicates that in middle age, negative cardiovascular processes may be occurring that could increase the risk of dementia much later in life,” Hörder added.
It is important to say that the study had its limitations: the sample was small and all the volunteers were Swedish women. As the researchers point out, women’s fitness levels were only measured once, so they do not confirm whether they maintained or improved their fitness levels after 1968. This could also affect the results.
However, previous research seems to support the relationship between physical activity and a significantly lower risk of developing dementia, even when the range is not as high as in this study.