Women who have a high cardiovascular fitness in middle age have a risk of developing dementia when older that is almost 90 percent lower than among women in average physical condition, according to a study published in the journal Neurology.
"This shows that we can affect our risk of dementia and Alzheimer's disease", says Ingmar Skoog, professor of psychiatry at Sahlgrenska Academy, Sweden, and director of AgeCap, Centre for Ageing and Health, at the University of Gothenburg.
The study is based on information from 191 women who underwent a fitness test on an exercise bike when they were on average 50 years old. The women pedaled up to their peak workload, at which point the results of their efforts on the bike were recorded.
Based on their results, women were categorized into high (40 women), medium (92 women) and low (59 women) fitness. Twenty of the women in the low-level category had to interrupt the test because of ECG changes high blood pressure or other cardiovascular problems.
During the subsequent 44 years, the women were tested for dementia on six times occasions. Of the 191 women, 44 developed dementia.
In the group that had the best results in the bike test, five percent developed dementia. In the medium fitness group, the share was 25 percent, and in the low fitness group, 32 percent. Of the women who had to interrupt the test, 45 percent developed dementia.
The women who had a high cardiovascular fitness in middle age and still developed dementia did so an average of 11 years later than those who were in the medium fitness group, or at age 90 years instead of age 79 years.
Helena Hörder, postdoctor at Sahlgrenska Academy and lead author of the article, emphasizes that the study does not point to a causal link between cardiovascular fitness in middle age and the risk of dementia. On the other hand, there is a clear connection.
"The results are exciting because of the possibilities of improving cardiovascular fitness in middle age, which could postpone or even protect against dementia. But more research is needed, including study of when during the lifecourse it's most important to have a high physical fitness," she maintains.
The study is based on the processing and analysis of results from the Prospective Population Study of Women in Gothenburg that began in 1968 and is managed within AgeCap. Limitations of the current study are the relatively low number of participants as well as the fact that their fitness were tested at only one occasion.