A physically active lifestyle has a sizeable impact in preventing the onset of cognitive dysfunction and dementia. These physical activities can range anywhere from simple walking to cardio and aerobic exercises like swimming. Extensive research has been conducted on this subject. Not only does physical exercise minimizes the risk of dementia, it may also help improve the cognitive function in people who already suffer from mild dementia.
How does physical activity prevent dementia?
Exercise helps reduce the gray matter and hippocampal loss
What is the gray matter? It is the gray substance of the brain that plays a vital role in memory, attention, and language. The volume of gray matter is a measure of the density of cells in a particular brain region. The lesser the density of brain cells, the less is the volume of gray matter and vice versa. With aging, individuals with a sedentary lifestyle experience a significant loss of the gray matter volume. Hence, they are easily prone to developing memory issues in later life.
In addition, the volume of hippocampus shrinks as we age. Hippocampus is a brain center involved in memory retrieval and processing. It is one of the first few brain regions affected earlier in the course of dementia. Degeneration of hippocampus is most prominent in people who lead a sedentary lifestyle.
A detailed scientific analysis retrieving data from multiple sources showed that aerobic exercise limits the age-related loss of the gray matter and hippocampus volume.1 Thus, it helps prevent dementia.
Physical activity increases brain plasticity
Brain plasticity is the brain’s ability to mold, modify, and restructure its electrical networks in response to new information, injury, development, or environmental stimuli. This adaptability of the brain enables us to encode and retain memories. Exercise enhances the brain plasticity and thus optimizes learning, memory, as well as cognition.2 Cardiac fitness exercises play a significant part in maintaining the exercise-induced benefits on the brain. 2
The increase in gray matter volume in response to aerobic exercise is one paradigm of brain plasticity.
Exercise promotes the growth and survival of nerve cells
In Alzheimer’s disease, there is a significant loss of nerve cells. In contrast, exercise favors the development and maturation of a vast array of nerve cells or neurons. This is possible through the production of specialized brain proteins during exercise.3
People who remain physically active throughout their lives, especially in middle age are less likely to develop dementia as compared to inactive people.
- Ahlskog JE, Geda YE, Graff-Radford NR, Petersen RC. Physical Exercise as a Preventive or Disease-Modifying Treatment of Dementia and Brain Aging. Mayo Clinic Proceedings. 2011;86(9):876-884. doi:10.4065/mcp.2011.0252.
- Hötting K, Röder B. Beneficial effects of physical exercise on neuroplasticity and cognition. Neurosci Biobehav Rev. 2013;37(9 Pt B):2243-57. doi: 10.1016/j.neubiorev.2013.04.005.
- Sleiman SF, Henry J, Al-Haddad R, et al. Exercise promotes the expression of brain derived neurotrophic factor (BDNF) through the action of the ketone body β-hydroxybutyrate. Elmquist JK, ed. eLife. 2016;5:e15092. doi:10.7554/eLife.15092.