The data here looks great: 50% reduction in risk for Alzheimer’s disease (AD) among exercisers.
But what does that really mean and why does this study (the picture is a link, hint, hint) mean so much in light of the preponderance of studies showing little to no benefit from exercise?
For one thing, this study has a large subject pool of older people who’ve been followed for 30 yrs or so and have had their brains MRI’d to measure changes over time. That makes it a stronger study than many that simply measure changes in the brain over short periods of time in light of controlled exercise programs.
But it also provides some encouragement to those who are not inclined or able to exercise vigorously as it simply argues on behalf of different kinds of activity as being beneficial. In other words, even gardening or mall walking counts.
However, while encouraging, supportive and possibly motivating, this study may also be deluding. We all know people who have been fit, healthy, lean, etc and who still got AD.
So what’s someone to take from this kind of study and these kinds of results?
Without wanting to sound like a naysayer, though I often assume such a role when it comes to health and exercise studies, I just want to say that one should not start an exercise program just to reduce your risk of AD. There are many benefits to exercise and some of these may not come your way. Eat right, sleep well, exercise consistently and still you may get cancer, dementia, heart disease, or simply die young.
So when you see a stat that says you can reduce your risk by 50%, note that (1) your risk for any particular disease may be so low that a reduction in risk may not be that valuable but (2) if you have a high risk of AD this may be one healthy way of cutting that risk in half.
So start your exercise program now and see what life has to offer.