Scientists studying Alzheimer's have found that staying moderately active can lead to healthier brain functions in those at risk of developing the disease, potentially giving us another clue how to beat the condition.
In particular the research looked at glucose metabolism, the process that gives brain cells the right amount of fuel, and that also happens to break down with the onset of Alzheimer's.
Scientists from the University of Wisconsin-Madison found that study participants who spent at more than an hour per day taking part in moderate physical exercise showed greater levels and healthier levels of glucose metabolism than those who didn't.
"This study has implications for guiding exercise 'prescriptions' that could help protect the brain from Alzheimer's disease," says one of the team, Ryan Dougherty.
"While many people become discouraged about Alzheimer's disease because they feel there's little they can do to protect against it, these results suggest that engaging in moderate physical activity may slow down the progression of the disease."
The study used accelerometers to measure a week's worth of physical activity for 93 middle-aged volunteers, all at high genetic risk of Alzheimer's but so far showing no cognitive signs of the disease.
Physical activity was split into light (the equivalent of walking slowly), moderate (a brisk walk), and vigorous (a strenuous run). This collected data was then compared against glucose metabolism levels in the brain.
Using a special imaging technique called 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) to trace glucose metabolism, the researchers found healthier patterns in moderately active patients in all areas of the brain under observation.
The link is enough for the researchers to suggest physical exercise is an "important contributor" to brain health for those at risk of Alzheimer's, though they also stress that further research is required to establish how staying active might be connected to the chances of developing Alzheimer's later in life.
Plenty of previous studies have found associations between exercise and improved memory, and there's a growing pile of evidence that exercise boosts brain power as well as other parts of the body. Now we just need to figure out how Alzheimer's fits into all this.
A small 2016 study found that exercise could be one factor in reversing the effects of Alzheimer's, alongside changes to diet and sleep habits, and a personalised program of vitamins and other drugs.
Everyday exercises such as gardening or walking are already recommended for those suffering from dementia – as well as just about everyone else – but scientists are still trying to pin down the details.
According to one of the researchers, Ozioma Okonkwo, ongoing research continues to take a closer look at how exercise could perhaps protect the brain from the onset of Alzheimer's off the back of this new study.
"Seeing a quantifiable connection between moderate physical activity and brain health is an exciting first step," he says.
The findings have been published in the Journal of Alzheimer's Disease.