Moving Your Body May Help “Clean” Your Brain, According to New Research

Key Takeaways

• New research suggests that even small body movements may help circulate fluid that clears waste from the brain.
• Experts say exercise supports brain health in multiple ways, including improving memory, mood, stress levels, and blood flow.
• While the new “brain cleaning” findings were observed in mice, scientists say the evidence linking regular physical activity to better brain health in humans is already strong.

We know that exercise is good for our physical health, but mounting research is showing that it can help improve our brain health, too. One example of this is a recent study published in Nature Neuroscience that found that even simple body movements—like tightening your abdominal muscles—can trigger a process that helps flush waste out of your brain.

But how, exactly, does this work? And what does it mean to “clean” your brain? We spoke with neurology experts to find out, and learn about other ways exercise can benefit brain health.

How Does Exercise “Clean” the Brain?

This study found that when we move our bodies, even subtly, our abdominal muscles create pressure changes that gently move the brain within the skull. “That’s important because movement appears to help circulate cerebrospinal fluid, the fluid that surrounds the brain and spinal cord,” says David Perlmutter, MD, a board-certified neurologist and the author of Brain Defenders: Harness the Power of Your Immune Cells to Protect Your Brain for Life. “The researchers believe this effect on the spinal fluid may help the brain clear away waste products that could otherwise contribute to neurodegenerative disease.”

So far, this research has only been conducted in mice, so we can’t directly apply its findings to humans yet, but “basic science research like this is how we build the foundation for understanding human biology,” says Janina Kamm, PsyD, a clinical neuropsychologist and assistant professor at The Chicago School. 

Before we can fully understand how to keep human brains healthy, we need to first understand the mechanics of how the brain works. According to Kamm, studies like this one help researchers build that understanding. “While the exact ‘hows’ and  ‘whys’ are still being worked out, the scientific evidence for the benefits of exercise in humans is already massive,” she says. “Of all the things we can do to support a healthy brain, regular physical activity has some of the strongest evidence behind it.” 

The findings of this study are interesting to researchers because when the brain moves within the skull, the fluid within and around the brain moves with it, Kamm says. “There is another fluid called interstitial fluid that lives between brain cells and carries waste products produced by the brain,” she explains. “In theory, brain movement could push interstitial fluid outward toward the space surrounding the brain, where we have a built-in drainage system. By encouraging movement of this fluid toward our waste-clearing systems, we may more effectively ‘clean’ the brain.” 

What Does It Mean to “Clean” the Brain?

So, what exactly does it mean when we talk about “cleaning” the brain? While soap and water aren’t involved, the concept is similar.

“Brain ‘rinsing’ or ‘cleaning’ refers to the biological process where fluid flows into, through, and out of the brain tissue to flush away metabolic waste products,” says D. Kojo Hamilton, MD, a board-certified neurological spine surgeon and professor of neurological surgery at the University of Pittsburgh School of Medicine. 

This is accomplished by two primary fluids: cerebrospinal fluid (CSF)—the clear fluid surrounding the brain—and interstitial fluid (ISF), which is found in the spaces between individual brain cells. These fluids move through and around brain tissue and help remove metabolic waste, inflammatory compounds, excess proteins, and cellular debris, Dr. Perlmutter explains. “A simple way to think about it is like rinsing a sponge,” he says. “When the brain moves slightly, fluid shifts through brain tissue and may help wash out unwanted waste products.”

We already know that deep sleep plays a major role in this cleansing process. Previous research has shown that during deep sleep, cerebrospinal fluid flow increases and helps clear metabolic waste from the brain, including proteins associated with Alzheimer’s Disease, Dr. Perlmutter says.

“What makes this new study especially important is that it suggests we now have another potential tool for supporting this ‘cleaning’ process: movement and exercise,” he explains. “The findings imply that physical activity may promote fluid movement in the awake brain through gentle mechanical motion of the brain itself.”

This is an area of ongoing study. “Scientists are still working out the full picture for what happens when that waste removal system is disrupted or inefficient,” Kamm says.

What Other Ways Does Exercise Improve Brain Health?

In addition to “cleaning” the brain, moving your body can also contribute to brain health in a number of ways, including:

Balancing Neurotransmitters and Mood

“Exercise elevates the production of serotonin, dopamine, and norepinephrine, which play foundational roles in sharpening attention and regulating mood,” Dr. Hamilton says. “It simultaneously curbs stress by regulating the release of the hormone cortisol.”

Improving Cognition

Different types of exercise may benefit different aspects of cognition. “For example, research suggests aerobic exercise may be particularly helpful for memory, while mind-body practices like tai chi show some promise for building executive function—things like mental flexibility and working memory,” Kamm says. 

Triggering Growth

Exercise stimulates the release of Brain-Derived Neurotrophic Factor (BDNF), a protein essential for the survival, growth, and proliferation of new neurons—particularly in the hippocampus, the brain’s memory center, Dr. Hamilton says. BDNF also supports the function of brain neurons and their connections, Dr. Perlmutter says. “This is especially important for our ability to learn and remember information,” Kamm adds. 

Reducing Stress

Exercise is great for your mental health, which in turn is great for your brain health. “Chronic stress and depression can negatively impact current cognitive functioning and increase the risk of cognitive decline and dementia in the future,” Kamm says.

Improving Blood Vessel Supply

Cardiovascular activity prompts the release of Vascular Endothelial Growth Factor (VEGF), creating new capillary beds. “This directly increases blood flow, supplying the brain with more oxygen and glucose required for optimal learning and cognitive flexibility,” Dr. Hamilton says. 

Read the original article on Real Simple