Could the key to preventing the onset of Alzheimer’s disease be in your feet?

A new study finds that older adults who exercise just a half hour a day are nearly 40 per cent less likely to develop Alzheimer’s than those who don’t exercise at all.

And seniors can reap the benefits of exercise even if they break up their physical activity into a few 10-minute segments throughout the day.

The research comes from the Ontario Brain Institute, which reviewed more than 850 studies on the matter. The researchers conclude that more than one in seven cases of Alzheimer's disease could be prevented if all older Canadians who are currently inactive -– which, statistics say, includes most of them -- were to get moving on a regular basis.

The study also found that regular physical activity can also help seniors who already have Alzheimer's or other dementias to better manage their disease.

“This, to me, is even more exciting, in a sense, because there is such a burden from Alzheimer’s at so many levels,” Dr. Donald Stuss, president and scientific director of the Ontario Brain Institute told CTV’s Canada AM Friday.

He said that seniors with dementia who exercise regularly have less depression, and are better able to take care of themselves in daily life, such as dressing and grooming.

“There are enormous benefits just by being active,” he said.

While many studies have shown how regular exercise can prevent a number of illnesses, from heart disease to cancer, it’s never been clear whether it can actually help prevent Alzheimer’s disease.

“There’s been this controversy for years about whether exercise really helps,” Stuss said. He says it was only recently that a number of high-quality studies have finally been conducted to look directly at the issue.

The OBI team was able to review 871 research articles on exercise and dementia conducted over the last 50 years, and narrowed in on the 45 best and largest studies.

The conclusion from the pooled data showed that seniors who reported over the years that they were the most physically active had a 38 per cent lower risk of developing Alzheimer's than those who were the least physically active.

They also calculated that, given that close to 60 per cent of seniors in Ontario are considered inactive, more than 1 in 7 cases of Alzheimer’s in the province can be attributed to inactivity, and could be prevented by getting inactive seniors moving.

“This is the first real significant evidence accumulated that… activity has a significant effect,” Stuss said.

Stuss notes that “activity” doesn’t have to mean intense exercise on a treadmill or at a gym.

“Because some people think, ‘I can’t exercise.’ But everybody can move,” he said.

“It should be enough that you can feel it – you’re not breathless, you can still talk, but you can feel that you’re active,” Stuss explained. “So, house cleaning for example, walking.”

The research also showed that it didn’t matter if the activity were completed all at once, either.

“One of the things we’re pushing is: build it into your day. Don’t think of it as a big thing; make a little commitment. Walk around the block. Do it in little bits. Break it into 10-minute segments.”

In 2011, around 747,000 Canadians over the age of 65, or about 15 per cent of that population, were living with some form of dementia. About two-thirds of those people suffering from Alzheimer’s disease.

The number of people living with Alzheimer’s is expected to triple in the next 40 years. The Alzheimer Society of Canada says that means that Canada could see 2.8 million dementia cases by 2050.