A restful night’s sleep has long been held as the solution for a variety of health issues, particularly in terms of purging harmful toxins from the brain. Esteemed neuroscientists have consistently claimed that deep sleep aids in the removal of troublesome brain debris, eliminating many proteins and metabolites associated with the development of Alzheimer’s and other types of dementia.
While this information has brought reassurance to many, a recent study in the journal Nature Neuroscience has brought this theory into question. While still crucial for overall health, Bill Wisden, a professor at the UK Dementia Research Institute, has proposed that being active actually plays a more significant role in toxin removal. “We have demonstrated that brain clearance is highly effective during waking hours,” Wisden confirms. “In general, being alert, active, and exercising can more efficiently cleanse the brain of toxins.”
This is certainly a promising breakthrough for those who struggle to attain seven hours of sleep each night. A brisk half-hour walk is something that most of us can manage, even after a night of restlessness.
Wisden’s argument is in line with an increasing volume of research findings that emphasize the critical role of exercise in upholding brain health.
Brain Waste Removal
The scientific community is currently focusing on the role of exercise in eliminating waste from the brain. Researchers speculate that exercise may stimulate brain cells called microglial cells to adopt a healthier, anti-inflammatory state. This allows these cells to serve as beneficial scavengers, purging waste and ensuring that neural connections are clean and properly functioning.
This theory is supported by Dr. Rebecca MacPherson, an associate professor at Brock University in Canada. “We are investigating the idea that exercise activates microglia in a manner that enhances their clearing of the products of metabolism,” MacPherson explains.
Brain Nourishment
Numerous studies have shown that regular physical activity reduces the risk of all forms of dementia by 28% and Alzheimer’s disease specifically by 45%. Much of this impact is attributed to a molecule called brain-derived neurotrophic factor or BDNF, which triggers the growth of new neurons and strengthens the connections between them.
“Muscle contractions increase BDNF, while the platelets in the blood store a significant amount of BDNF,” MacPherson reveals. “So with increased blood flow due to exercise, your blood platelets can release more of it into the circulation.”
In addition to BDNF, exercise also leads to the production of a hormone called irisin, which is capable of clearing amyloid plaques, according to a study published in the journal Neuron. This has sparked interest in developing an artificial form of irisin to treat neurodegenerative diseases, including Alzheimer’s and Parkinson’s.
Recommended Exercise Intensity
MacPherson concedes the difficulty in determining the precise exercise requirements, as everyone’s needs and capabilities are different. The NHS recommends at least 30 minutes of aerobic exercise daily, with higher-intensity workouts being particularly beneficial for BDNF production. However, regardless of the intensity, any form of exercise provides some benefit for the body and the brain.
Mood-Boosting Effects of Exercise
Beyond just benefiting the brain, physical activity has the potential to alleviate symptoms of depression, including low mood and loss of pleasure in activities. Professor Jonathan Roiser at University College London is leading a clinical trial to understand why exercise is advantageous for mental health, specifically targeting symptoms such as fatigue and difficulty with decision-making. The trial aims to provide concrete evidence for how exercise affects the production of dopamine and suppresses inflammation, both of which are interconnected with mental health.
As our understanding of how exercise protects the body develops, it could lead to the creation of new drugs, known as exercise mimetics, which mimic some of the benefits of physical activity. For most people, researchers have a simple message – maintaining an active lifestyle, whether through the gym or sports, will help keep your mind healthier for longer.