Study Finds One Way to Protect Against Dementia
Our primary care doctors in Delray Beach often receive questions from some of our older patients who are concerned about dealing with memory loss.
And with good reason. As many as six million Americans have a dementia diagnosis. The Alzheimer’s Association estimates that worldwide trends will result in an increase of nearly 6.8 million cases globally by the year 2050. These trends are smoking, sedentary lifestyles, high body mass index (BMI), high blood sugar, and the aging of the population. All of these are risk factors for developing dementia.
So is a family history of the disease. But researchers have been working for years to find ways to overcome the role genetics plays in developing dementia.
A simple treatment
Now a new study, published this month in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, has found that even a moderate amount of regular exercise can help improve the brain function and thinking skills of individuals with early signs of dementia.
The brains of most older adults accumulate amyloid and tau, Science Daily reports. These are toxic proteins that are typically considered the hallmarks of Alzheimer’s disease. Scientists believe amyloid accumulates first, then tau, causing synapses and neurons to fall apart, interfering with normal brain functioning.
“All of our thinking and memory occurs as a result of these synaptic communications,” study author Kaitlin Casaletto, told CNN in an email. Casaletto is an assistant professor of neurology in the Memory and Aging Center at the University of California San Francisco.
The beneficial effects of physical activity on thinking and memory have been demonstrated in mice. However, it’s have been much harder to prove in humans. Casaletto’s study tracked the physical activity of elderly participants, who also agreed to donate their brains when they died.
Her study demonstrated for the first time that exercise boosts levels of protein. This protein strengthens communication between brain cells via synapses. Researchers have known about the effect exercise has on improving memory, but until now they weren’t sure why.
“We have described, for the first time in humans, that synaptic functioning may be a pathway through which physical activity promotes brain health,” she said.
“I think these findings begin to support the dynamic nature of the brain in response to our activities, and the capacity of the elderly brain to mount healthy responses to activity even into the oldest ages,” she added.
She also pointed out that other studies have found similar correlations.
“Several prior studies consistently show . . . higher levels of these same synaptic proteins in brain tissue associate with better cognitive performance, independent of plaques and tangles,” she said.
Earlier studies have connected frailty as well as high blood pressure with an increased risk for dementia in older adults. Both of those conditions can be mitigated through regular exercise.
A 2017 study published in the British Journal of Sports Medicine found that individuals with early signs of vascular dementia improved their blood pressure along with thinking and memory skills. This was after walking vigorously just three times a week.
A more recent study by the Rush Memory and Aging Project published in the journal Neurology examined brain tissue samples of over 400 people who had died. It found that those who had engaged in regular physical activity had high levels of presynaptic proteins throughout their brains, not just in the hippocampus, the part that controls memory.
Of all the suspected causes of dementia, the study authors said that inactivity could account for more than four million cases of dementia.
How high a ‘dose’?
How much exercise is required to achieve this protective effect? Any activity is worthwhile, Casaletto said. And it seems the more, the better.
“The more physical activity, the higher the synaptic protein levels in brain tissue,” she told CNN. “This suggests that every movement counts when it comes to brain health.”
She recommended aiming for 150 minutes of physical activity a week. This doesn’t necessarily mean running on a treadmill or working out at a gym. Even small movements can add up. They’ve been shown to increase synaptic proteins. This is even in those who already have brain markers for Alzheimer’s or other forms of dementia.
Simple activities such as walking, climbing stairs, or gardening are a good way to begin. Even housework counts, as long as it’s a daily activity.
“It’s important to find an exercise you enjoy so it can sustainable in your routine,” Heather Snyder told CNN. Snyder is the vice president of medical and scientific relations for the Alzheimer’s Association, which partially funded the study. Snyder did not have involvement in the study.
“For older adults, it’s important to discuss any new physical activity with your doctor to make sure it’s safe to do so,” she added.