Physical Fitness Correlates with Lower Risk of Alzheimer's Disease
Physical fitness, and the exercise needed to produce that state, has a sizable influence on later life health. Along with calorie restriction, effect sizes on disease risk and mortality are larger for the average person than near any medical technology for which equivalent data exists. We might hope that senolytics, clearance of senescent cells, may prove to better, but that remains to be seen. Exercise and fitness affect the pace of neurodegeneration through numerous mechanisms, such as upregulation of neurogenesis, increased blood flow to the brain, slowing vascular aging, and so forth. The epidemiological data here adds to a sizeable existing set of studies showing the effects of fitness of late life health.
People who are more physically fit are less likely to develop Alzheimer's disease than people who are less physically fit, according to a preliminary study. The study involved 649,605 military veterans in the Veterans Health Administration database with an average age of 61 who were followed for an average of nine years. They did not have Alzheimer's disease at the start of the study. Researchers determined participants' cardiorespiratory fitness. Cardiorespiratory fitness is a measure of how well your body transports oxygen to your muscles, and how well your muscles are able to absorb oxygen during exercise.
The participants were divided into five groups, from least fit to most fit. Fitness levels were determined by how well participants did on a treadmill test. This test measures exercise capacity, the highest amount of physical exertion a person can sustain. For people who are middle-aged and older, the highest level of fitness can be achieved by walking briskly most days of the week, for two and a half hours or more per week.
The group with the lowest level of fitness developed Alzheimer's at a rate of 9.5 cases per 1,000 person-years, compared to 6.4 cases per 1,000 person-years for the most fit group. When researchers adjusted for other factors that could affect risk of Alzheimer's disease, they found that the people in the most fit group were 33% less likely to develop Alzheimer's disease than those in the least fit group.