Does Being Fit in Middle-Age Protect Against Dementia Later?

Does Being Fit in Middle-Age Protect Against Dementia Later?

(Last Updated On: April 1, 2019)

Does Being Fit in Middle-Age Protect Against Dementia Later?

The health benefits of exercise extend to every organ in your body including your brain. In fact, according to a new study, being physically fit when you’re middle-aged could pay off with a healthier brain later on. It’s one more bit of evidence that exercise offers health benefits for all the muscles and organs in your body including your brain.

Exercise – A Recipe for a Healthy Brain Later?

Researchers from Finland and the United States questioned almost 3,600 adults about their self-perceived fitness level during middle age. The average age of the adults was 50 years old. After following the adults for 30 years, they found those who reported being less physically fit during middle age were four times more likely to be diagnosed with dementia. The strongest link between mid-life fitness and dementia risk was seen in those, not at high genetic risk for dementia.

A number of other studies have found a link between exercise and a reduced risk for dementia. In fact, a recent study showed exercise helps prevent milder forms of cognitive impairment brought on by aging. A less severe form of cognitive dysfunction called mild cognitive impairment, or MCI affects thousands of adults as they age. In fact, between 10 and 20% of adults over the age of 65 suffer from mild cognitive impairment.

Mild cognitive impairment isn’t severe enough to be classified as dementia. People with MCI are more forgetful than most people their age, frequently lose their train of thought during conversations, have problems making decisions and forget the names of people they’ve recently met. Even though people with this mild form of cognitive dysfunction carry out their daily activities in a relatively normal matter, MCI is a strong risk factor for dementia. People with MCI develop dementia at a rate of between 10 and 30% annually, much higher than the average population.

Exercise, Brain Health, and Aging

The part of the brain impacted the most by mild cognitive dysfunction is an area involved in memory called the hippocampus. The hippocampus sends information from short-term memory to long-term memory for storage and retrieval later on. When the hippocampus is damaged or shrinks in size it’s more difficult to form long-term memories.

What happens to the hippocampus as we age? The hippocampus decreases in size and volume during late adulthood and is a prominent feature of people with mild cognitive impairment. While there aren’t many things that can reliably increase brain volume, exercise is one of them.

Researchers asked two groups of older women to take part in a six-month exercise program. One group stretched and did balance exercises twice a week. The second group did twice-weekly aerobic exercise. Prior to and at the end of the study, they had MRI imaging of their brains. The women that did aerobic training showed a 4% increase in brain volume in their hippocampus. Other research shows people with greater hippocampal volume perform better on verbal memory tests.

Can Exercise Build New Nerve Cells and Nerve Cell Connections?

Some of the most exciting research shows exercise increases “neurogenesis,” the formation of new nerve cells in the brain and central nervous system. In older mice, aerobic exercise is linked with the formation of new nerve cells in the hippocampus of the brain. These new nerve cells arise from stem cells.

How does this happen? Exercise increases levels of a protein called FNDC5. A small piece of FNDC5, called irisin, breaks off and goes to the brain. For there, researchers believe it boosts levels of another protein called brain-derived neurotrophic factor or BDNF. BDNF not only stimulates the birth of new nerve cells – it keeps existing ones alive and healthy.

The fragment of FNDC5 called irisin is a molecule of interest for other reasons. Research suggests it activates brown fat, a metabolically-inefficient form of fat that speeds up your metabolism. Exercise – good for your brain and good for your waistline.

Other Ways Exercise Improve Brain Health

Exercise also triggers the release of mood-altering chemicals called endorphins that have a calming effect. A number of studies show regular exercise has mood-elevating benefit. As such, it may be helpful for people suffering from mild to moderate depression. In fact, some research show exercise is as effective as prescription antidepressants for treating depression – and has only GOOD side effects.

Strength Training and Brain Health

You might assume aerobic exercise is the most effective form of exercise for tuning up your brain. Not necessarily so. In one study, a group of 77 women with mild cognitive impairment resistance trained twice a week for 60 minutes over a 12 month period. Another group did aerobic exercise while still another did balance exercises.

Not only did the resistance training group perform better on test of verbal and visual memory, but functional MRIs of their brains also showed changes consistent with improved cognitive function. The aerobic training group experienced improvements too but not as much as the group that resistance trained.

The Bottom Line?

You may have heard the saying, “What’s good for your heart is also good for your brain.” That’s certainly true when it comes to exercise. Not to mention exercise is good for every other part of your body. There’s evidence that doing brain exercises like crossroad puzzles and memory games helps keep your brain healthy but even more powerful are the brain benefits of physical exercise. So do those crossword puzzles to challenge your mind but give your brain a different kind of workout through a combination of aerobic and resistance training.



Medical News Today. “Self-Rated Physical Fitness in Midlife and Indicator of Dementia Risk”

MedPage Today. “Aerobics May Build Bigger Brains in Older Women”

British Journal of Sports Medicine. “Aerobic Exercise Increases Hippocampal Volume in Older Women WithProbable Mild Cognitive Impairment”. (2014)

Mayo Clinic. “Mild Cognitive Impairment Symptoms”

Brain Behav Immun. 2012 Jul;26(5):778-88.

Science Now. “How Exercise Beefs Up the Brain”

Harvard Medical School. “Exercise and Depression”

US News and World Report. “Strength Training May Give Boost to Seniors’ Brains”


Related Articles By Cathe:

3 Ways Exercise Affects Brain Function and Mood

Memory Jolt: Can a Workout Instantly Improve Your Memory?

Recently Discovered: A New Link Between Exercise and Aging

Take a Mental Health Break – Exercise!

7 Simple Ways to Preserve Your Brain Health


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