• Posted November 21, 2024

Getting Fitter Can Really Help Keep Dementia at Bay

People whose genes put them at high risk for dementia may be able to fight Mother Nature and win, new research out of Sweden suggests.

The weapon: Working out on a regular basis to improve cardiorespiratory fitness, also known as CRF. 

CRF is the capacity of the body's circulatory and respiratory systems to supply oxygen to muscles -- a capacity that declines as people age and lose muscle, starting in their 20s and accelerating over time. 

By the time folks reach their 70s, CRF drops off more than 20% per decade.

Low CRF is a strong predictor of early death from all causes and heart-related events such as strokes and heart attacks. 

"Our study shows that higher CRF is associated with better cognitive function and decreased dementia risk," the Swedish researchers concluded. "Moreover, high CRF may buffer the impact of genetic risk of all dementia by 35%."

For the study, a team led by Weili Xu, of the Aging Research Center at Karolinska Institute in Stockholm, looked at data on more than 61,200 people between the ages of 39 and 70. They were enrolled in the UK Biobank study between 2009 and 2010 and were followed for up to 12 years.

At the start of the study, all were dementia-free. Each took a six-minute ride on a stationary bike to determine their CRF. They also took cognitive tests and their genetic risk for dementia was gauged using a standard score for Alzheimer's disease.

In all, 553 participants -- 0.9% -- were diagnosed with dementia during the 12-year followup.

Compared to people with low CRF, the onset of dementia was delayed by almost 1.5 years for people with a high CRF. A high CRF also reduced the risk of dementia by 35% among people with a moderate-to-high risk score.

The findings were published Nov. 19 in the British Journal of Sports Medicine.

Researchers emphasized that their study doesn't prove cause-and-effect, only that there's a link between the two.

Significantly, they said the number of dementia cases may be underestimated because participants in the UK Biobank are typically healthier than the overall population. In addition, people with certain health conditions didn't take the exercise test.

Despite these and other limitations, the authors said in a journal news release that "enhancing CRF could be a strategy for the prevention of dementia, even among people with a high genetic predisposition for Alzheimer's disease."

They said further study of the relationship between CRF and brain health, and how it might affect the link between genetic risk and dementia, is needed.

More information

There's more about reducing your risk for dementia at Alzheimers.gov.

SOURCE: BMJ Group, news release, Nov. 19, 2024