As New Pharmaceuticals Fail to Treat Alzheimer's, We Already Have a Good Way to Prevent It
Over the preceding decades, hundreds of potential treatments for Alzheimer's Disease have failed to show clinical benefits in human trials, crashing and burning with a consistency that Stat News' Damian Garde called "metronomic." That's terrible news for the more than five million Americans who currently have Alzheimer's and the more than fourteen million who will be living with it by 2060.
It seems that the primary hypothesis for the cause of Alzheimer's – that a buildup in the brain of a protein called beta-amyloid is responsible for cognitive decline – is wrong. Drugs that reduce beta-amyloid don't resolve Alzheimer's patients' crippling dementia.
But despite a landscape of pharmaceutical solutions that's largely devoid of hope, there does exist a widely available therapeutic that has proven highly effective at preventing Alzheimer's: exercise.
According to the Alzheimer's Society, "Several prospective studies have looked at middle-aged people and the effects of physical exercise on their thinking and memory in later life. Combining the results of 11 studies shows that regular exercise can significantly reduce the risk of developing dementia by about 30 percent. For Alzheimer's disease specifically, the risk was reduced by 45 percent."
Those numbers are truly remarkable, but there are a few nuances. First off, physical activities like simple household chores, work-related movement, and walking do not seem to cut into Alzheimer's risk. It takes a little more effort.
"Vigorous exercise, regular exercise, leisure time physical activities, and gardening showed a positive effect toward lowering dementia risk," Yonsei University Professor Junga Lee wrote in a 2018 systematic review.
Moreover, the exercise must be regular and sustained, something like a few hours a week spread over at least three sessions. And it has to start in middle age or earlier. Initiating an exercise regimen past age sixty is highly salubrious, but it doesn't seem to pack as much of an anti-Alzheimer's punch as doing so in one's forties.
Unfortunately, while exercise seems to be a great way to prevent the onset of Alzheimer's, it cannot unwind the disease once it sets in. Studies suggest that physical activity can improve cognitive function in Alzheimer's sufferers and maybe even slightly slow the disease's progression, but it cannot reverse it.
So as millions of patients, friends, and family members afflicted by Alzheimer's Disease earnestly wait for a rapid and effective treatment, all of us can regularly exercise to lessen Alzheimer's future burden.