According to a new study from researchers at UCLA Medical Center and the University of Pittsburgh, physical activity – anything from weeding your garden to grabbing your partner for a spin around the dance floor – can lower your risk of Alzheimer’s disease by as much as 50 percent.

And you don’t need to become a late-in-life gym rat in order to keep Alzheimer’s at bay. Researchers found that any form of aerobic exercise – that’s activity that gets your heart pumping – improves the structure of your brain, lessening your risk of developing Alzheimer’s, in this first-of-its-kind study.

The study, funded by the National Institute of Aging, appeared in the March 121 issue of the Journal of Alzheimer’s Disease.

Researchers focused on more than 800 participants from the 30-year Cardiovascular Health Study (funded by the National Heart, Lung and Blood Institute to determine the risk factors of cardiovascular disease and stroke in those 65 years of age and older), and determined through brain scans that the regions of the brain associated with memory including the hippocampus had more volume in those who were physically active compared to those who weren’t.

 “This is the first study in which we have been able to correlate the predictive benefit of different kinds of physical activity with the reduction of Alzheimer’s risk through specific relationships with better brain volume in such a large sample,” said the study’s lead author, Dr. Cyrus A. Raji of UCLA.

Previous research has shown that regions of the brain associated with memory such as the hippocampus shrink in people who develop Alzheimer’s disease.

Other studies have determined that exercise is beneficial, but this is the first to show that even active hobbies can help decrease the risk of dementia.

These activities also helped improve the brain volumes of those in the sample – about 25 percent – who were experiencing cognitive impairment associated with Alzheimer’s.

“Currently the greatest promise in Alzheimer’s disease research is lifestyle intervention including increased exercise. [This research is] a landmark study that links exercise to increases in grey matter and opens the field of lifestyle intervention to objective biological measurement,” said George Perry, editor in chief of Journal of Alzheimer’s Disease.

According to the Alzheimer’s Association, 5.1 million Americans are currently diagnosed with Alzheimer’s disease. Those numbers are expected to reach 13.8 million over the next 30 years.

“We have no magic bullet cure for Alzheimer’s disease,” Raji said. “Our focus needs to be on prevention.”

Previous research also touted exercise

Similarly, a 2014 study found that exercise helps prevent the structural changes in the brain associated with Alzheimer’s.

“There’s good reason to tell people to exercise,” said Dr. Stephen M. Rao, a professor at the Schey Center for Cognitive Neuroimaging at the Cleveland Clinic who headed the study that appeared in the journal Frontiers in Aging Neuroscience.

That study found that aerobic activity not only helped boost brain health by increasing blood flow to the brain, but also by protecting brain connections that are lost as part of the aging process.

Another study – this one from researchers at the University of Maryland School of Public Health – found that moderate exercise boosts the outer layer of the brain called the cortex, a move that improved memory in just three months.

Beyond the brain

If lowering your risk of Alzheimer’s isn’t enough incentive to get moving, there are a host of other reasons why it’s never too late to make exercise an integral part of your life.

According to Dr. James Rimmer, director of the National Center on Health, Physical Activity and Disability, the risks associated with being a couch potato go far beyond the brain.

Not only that, skipping out on exercise leads to increased muscle loss that can make everyday activities including grocery shopping, getting dressed and playing with the grandkids more difficult. Muscle decline begins after age 30, and those who are physically inactive can lose as much as 3 to 5 percent of muscle mass per decade, a big deal if you find yourself retired at 65 and unable to do all the things you’d planned for because your body won’t cooperate.

 And for anyone who has ever found a blue mood blasted away after a hike in the woods on a sunny autumn day, a sedentary lifestyle can elevate the risk of clinical depression and anxiety, which can also have a negative impact on those golden years.

Exercise also leads to a stronger immune system, experts say.