A British study has suggested that just 20 minuteS of exercising, thrice a week, could drastically reduce the risk of Alzheimer's.
Even getting off the bus one stop early and walking the rest of the way could help in preventing the debilitating illness.
A third of all cases are due to lifestyle reasons including inactivity, obesity, smoking, high blood pressure and having a poor education, according to Cambridge researchers. But of these, a lack of exercise was found to be the single most important cause, Daily Mail reported Monday.
Researchers believe regular physical activity ensures there is a steady flow of oxygen-rich blood to the brain. This is thought to prevent the build-up of plaques "deposits of protein in the brain" which cause Alzheimer's.
Researchers say adults can drastically lower their risk even by just walking to work.
Carol Brayne, from Cambridge University's Institute of Public Health, said: "The important message is that there are aspects of healthy life which reduce risk.
"This doesn't say we can prevent dementia and Alzheimer's altogether. But there is a proportion which is preventable. Even just having a vigorous walk a few times a week, and ideally make it social event.
"It's really difficult for many people to take exercise. If nothing else is possible, even a walk will help. That's what evidence suggests.
"So 20 minutes to half an hour, three times a week. I would say to just fit something into life in the best possible way. This might be getting off the bus stop the next stop up, and walk the last bit."
A total of 850,000 Britons have been diagnosed with dementia "including Alzheimer's" although this will more than double by 2050 as the population ages.
The study was published in Lancet Neurology journal.
