Scientists have collected plenty of evidence linking exercise to brain health, with some research suggesting fitness may even improve memory.
What happens during exercise to trigger these brain health benefits?
New UT Southwestern research that mapped brain changes after one year of aerobic workouts has uncovered a potentially critical process: Exercise boosts blood flow into two key regions of the brain associated with memory. Notably, the study showed this blood flow can help even older people with memory issues improve cognition, a finding that scientists say could guide future Alzheimer’s disease research.
“Perhaps we can one day develop a drug or procedure that safely targets blood flow into these brain regions,” says Binu Thomas, Ph.D., a UT Southwestern senior research scientist in neuroimaging. “But we’re just getting started with exploring the right combination of strategies to help prevent or delay symptoms of Alzheimer’s disease. There’s much more to understand about the brain and aging.”
Blood flow and memory
The study, published in the Journal of Alzheimer’s Disease, documented changes in long-term memory and cerebral blood flow in 30 participants, each of them 60 or older with memory problems. Half of them underwent 12 months of aerobic exercise training; the rest did only stretching.
Exercise group showed 47 percent improvement in memory scores
The exercise group showed 47 percent improvement in memory scores after one year compared with minimal change in the stretch participants. Brain imaging of the exercise group, taken while they were at rest at the beginning and end of the study, showed increased blood flow into the anterior cingulate cortex and the hippocampus — neural regions that play important roles in memory function.
Other studies have documented benefits for cognitively normal adults on an exercise program, including previous research from Thomas that showed aging athletes have better blood flow into the cortex than sedentary older adults. But the new research is significant because it plots improvement over a longer period in adults at high risk to develop Alzheimer’s disease.
“We’ve shown that even when your memory starts to fade, you can still do something about it by adding aerobic exercise to your lifestyle,” Thomas says.
Mounting evidence
The search for dementia interventions is becoming increasingly pressing: More than 5 million Americans have Alzheimer’s disease, and the number is expected to triple by 2050.
Recent research has helped scientists gain a greater understanding of the molecular genesis of the disease, including a 2018 discovery from UT Southwestern’s Peter O’Donnell Jr. Brain Institute that is guiding efforts to detect the condition before symptoms arise. Yet the billions of dollars spent on researching how to prevent or slow dementia have yielded no proven treatments that would make an early diagnosis actionable for patients.
UT Southwestern scientists are among many teams across the world trying to determine if exercise may be the first such intervention. Evidence is mounting that it could at least play a small role in delaying or reducing the risk of Alzheimer’s disease.
For example, a 2018 study showed that people with lower fitness levels experienced faster deterioration of vital nerve fibers in the brain called white matter. A study published last year showed exercise correlated with slower deterioration of the hippocampus.
Regarding the importance of blood flow
Regarding the importance of blood flow, Thomas says it may someday be used in combination with other strategies to preserve brain function in people with mild cognitive impairment.
“Cerebral blood flow is a part of the puzzle, and we need to continue piecing it together,” Thomas says. “But we’ve seen enough data to know that starting a fitness program can have lifelong benefits for our brains as well as our hearts.”
1. Binu P. Thomas, Takashi Tarumi, Min Sheng, Benjamin Tseng, Kyle B. Womack, C. Munro Cullum, Bart Rypma, Rong Zhang, Hanzhang Lu. Brain Perfusion Change in Patients with Mild Cognitive Impairment After 12 Months of Aerobic Exercise Training. Journal of Alzheimer’s Disease, 2020; 75 (2): 617 DOI: 10.3233/JAD-190977
Razi Berry is the founder and publisher of the journal Naturopathic Doctor News & Review, which has been in print since 2005, and the premier consumer-faced website of naturopathic medicine, NaturalPath. She is the host of The Love is Medicine Project docuseries, The Natural Cancer Prevention Summit, The Heart Revolution-Heal, Empower and Follow Your Heart, and the popular 10-week Sugar Free Summer program. From a near death experience as a young girl that healed her failing heart, to later overcoming infertility and chronic fatigue syndrome and fibromyalgia through naturopathic medicine, Razi has lived the mind/body healing paradigm. Her projects uniquely capture the tradition and philosophy of naturopathy: The healing power of nature, the vital life force in every living thing and the undeniable role that science and mind/body medicine have in creating health and overcoming dis-ease. You can follow Razi on social media: Facebook at Razi Berry, Instagram at Razi.Berry and join the Love is Medicine group to explore the convergence of love and health. Look for more, and listen to more Love is Medicine podcast episodes here.