Apr 30, 2020 at 2:11 PM
Physical activity is well-known for its benefits related to weight control, reduced risk of cardiovascular disease, and elevated blood glucose levels. Increasing data is accumulating, however, about the effect it has on our brains.
For most people, concerns about brain health often do not surface until later in life as they begin to experience changes associated with the aging process. Brain health actually begins shortly after conception. Research indicates that a number of factors can affect brain size and activity, including exposure to physical activity.
The development of the brain and central nervous system appears to occur in stages, one building upon another. The process can be stimulated by physical activity. A woman who is physically active before and during pregnancy has the opportunity to affect better brain performance in her child.
Stimulation of the brain from physical activity is especially important during the years of growth and development. It helps to create new neurons and connections within the brain and nervous system.
The Physical Activity Guidelines Advisory Committee Scientific Report 2018 (from the U.S. Department of Health and Human Services) noted the connection between physical activity and better brain cognition. They noted benefits such as better processing speed, memory, and higher executive functions (reasoning, planning, organizing, problem-solving, etc.) with higher levels of physical activity.
The Guidelines establish recommendations for physical activity beginning at age three.
They suggest that 3-5 year olds be active throughout the day. The goal for 6-17 year olds is > 60 minutes of moderate to vigorous activity daily with vigorous activity occurring at least three times a week. They should also do activities that strengthen muscles and bones several times a week.
Adults should try for 150-300 minutes of moderate or 75-150 minutes of vigorous cardiovascular exercise each week. They should also do moderate to vigorous muscle strengthening exercises at least twice a week. Older adults and those with disabilities should stay as active as they can with cardio and strength activities based on their health status.
Unfortunately, only a small percentage of individuals in all age categories achieve these goals. For the adolescent period, for example, which is when the brain and nervous system are maturing, statistically only about 20% fulfill the physical activity recommendations.
In children and teens, studies indicate that higher levels of physical activity are associated with better test scores, greater learning, improved reading skills, and greater understanding. The subjects of math and reading have the strongest connection. More specifically, cardiovascular activity seems to help with attention, planning, working memory, and inhibitory control.
Ongoing studies are investigating the reasons for the connections between physical activity and better brain health and numerous possibilities exist. A key player appears to be something called “brain-derived neurotrophic factor” (BDNF) that is stimulated by physical activity. This substance is important for the survival, growth, and maintenance of neurons in circuits related to emotional and cognitive function.
BDNF can also improve brain plasticity (the ability to adapt to changing conditions) and can enhance the strength of neural networks related to learning and memory. The extent of the response by BDNF is based on the intensity, duration, frequency, and type of physical activity.
Stress can decrease the BDNF response, which can interfere with the creation of new brain cells and potentially impair learning, memory, and overall brain performance. The good news is that physical activity is a great stress-buster.
Increased heart rate can maximize blood flow (nutrients, oxygen) to brain tissues to allow for optimal performance. Physical activity can also counter the oxidative stress and inflammation caused by obesity, elevated blood glucose, and high blood lipids that can impede blood flow to the brain.
Related to quality of life, physical activity can reduce levels of anxiety and depression, while improving overall mood and emotional well-being. It can also increase the effectiveness of anti-depressant medications.
For middle-age and older adults, physical activity can delay brain aging, improve cognitive processes, can be analgesic for pain, and can improve mood. The natural course of aging decreases blood flow to the brain by about 5% a year. Physical activity can help to maximize the flow.
The Alzheimer’s Association suggests that physical activity can reduce the risk of both vascular dementia and Alzheimer’s disease. Persons with type 2 diabetes are at greater risk for Alzheimer’s as it can increase inflammatory and oxidative/metabolic changes that can lead to cognitive decline due to damage to neurological tissues. Persons with diabetes should establish a lifetime of physical activity as soon as they are diagnosed.
In persons with established brain-associated conditions such as Parkinson’s disease, multiple sclerosis, stroke, and dementia, physical activity can improve functioning. This means being able to sustain independence in activities of daily living and better quality of life for a longer period of time.
Brain health, then, is not just a concern for the older years of life. It is a life-long process that starts at the early stages of growth and development, progresses through childhood and adolescence, and continues through the adult years. Physical activity is a controllable factor that can enhance the brain and nervous system so that it is functioning optimally.
Pam Stuppy, MS, RD, CSSD, LD is a registered, licensed dietitian with nutrition counseling offices in York, ME and Portsmouth, NH. She has also been the nutritionist for Phillips Exeter Academy, presents workshops nationally, and is Board Certified as a Specialist in Sports Dietetics. (See www.pamstuppynutrition.com for more nutrition information, some healthy cooking tips, and recipe ideas).