Fitness and Dementia

More than 5 million people in the U.S. are living with Alzheimer's disease, the most common form of dementia. There is no cure or prevention for Alzheimer's disease, despite all the research into its causes.

Now a new study spanning 46 years offers some tantalizing clues. Way back in 1968, researchers in Sweden enrolled 191 women 38-60 years old into a study of cardiovascular fitness, as measured by their capacity to exercise on a bicycle until they became so fatigued that they had to stop. Based on their workload achieved, they separated the women into "low", "medium" and "high" fitness groups. Then they followed the women for the next 44 years, looking for signs of dementia, among other health issues. Surprisingly, they found that compared to the "medium" fitness group, those in the "high" fitness group were 88% less likely to develop dementia. Among those who did develop dementia, high fitness delayed the time to onset of dementia by 5 years, compared to the medium fitness group.

A word of caution; these results show a correlation only; they do not prove that high fitness per se is what is reducing the risk of dementia. Perhaps the high fitness group also has a better diet, or just better genetics to begin with. Nevertheless, the results are intriguing, and may point the way to additional research to tease out the actual cause. Anything we can do to solve this baffling and debilitating disease would be welcome.