We all know that eating well and exercising consistently can help us achieve the best health possible now. But exercise at mid-life might result in more than bigger biceps — it could mean maintaining our brain size as we age.
A recent study published online in the journal Neurology shows a link between physical fitness levels in middle-aged adults and brain size later in life.
As we age, certain parts of the brain shrink, especially the prefrontal cortex (an area at the front of the frontal lobe) and the hippocampus. Both areas are important to learning, memory, planning and other complex mental activities.
Fitness and its effect on the brain
The new research was conducted as part of the Framingham Heart Study, which began in 1948 in Framingham, Mass. as a way to study to identify risk factors for heart disease in a large group of people over a long period of time.
The study, which is now on its third generation of participants, looked at the connection between the cardiovascular fitness of people in their 40s and the size of their brains over time.
It found that middle-aged people who had poor cardiovascular fitness and a higher blood pressure and heart rate response to exercise had smaller brain volumes nearly 20 years later.
Cross-sectional and short-term observational studies have shown a link between lower fitness levels and increased brain atrophy in patients with Alzheimer’s disease, the researchers say.
The researchers theorize that exercise training programs may increase blood flow and oxygen delivery to your brain, improve
your brain’s ability to reorganize itself by forming new neural connections, and prevent age-related brain atrophy over the short term. But it’s unclear, the researchers say, whether physical fitness throughout all of adulthood has an impact on brain aging in later life.
Your brain and fitness
A number of studies have shown that exercise can remodel the brain by prompting creation of new brain cells and inducing other changes. A 2014 study on rats, for example, showed that inactivity can physically alter the brain. That study found that being sedentary changes the shape of certain neurons in ways that significantly affect the brain.
But this study may highlight the importance of working to stay fit past middle age, says neurologist James Leverenz, MD. Dr. Leverenz did not participate in the study.
”What they noticed was that people who were not in good of shape at 40 had smaller brain sizes at 60,” Dr. Leverenz says.
Dr. Leverenz cautions, however, that researchers were unable to attribute the differences in brain sizes to differences in thinking skills. Participants in the study scored similarly on memory tests while in their 60s whether their brains were smaller or had stayed the same.
More research needs to be done to determine whether smaller brain size impacts the risk for developing dementia and Alzheimer’s once people reach their 70s or 80s, Dr. Leverenz says.
Exercise is still good for the brain
Even so, Dr. Leverenz says, exercise can positively affect your brain indirectly by keeping you in better general health.
He adds that exercise might even directly improve brain health through improved blood flow and increased growth factors needed for brain cell health.
While the study was not able to prove that physical fitness had a direct impact on brain aging in later life, Dr. Leverenz says staying in good shape is a good way to help preserve the health of your entire body, including your brain.
“I think it reinforces what a lot of us have been saying — that exercise is good for your brain and keeps your brain healthier,” Dr. Leverenz says. “This is evidence that your brain actually is larger if you exercise and if you’re in better shape.”
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