Dementia is a medical condition that hits close to home for more and more people. According to the World Health Organization, around 50 million people have dementia, and there are nearly 10 million new cases every year. Chances are, it is affecting your life through those you know and care about.
In 1999 a group of scientists discovered that running caused new brain cells to form in mice (3). Before this, it was believed we had a set number of brain cells at birth and it was not changeable. This and other studies on exercise and the brain shifted our thinking about exercise beyond just the health of the body. This started a cascade of studies that are providing more and more information about how exercise helps the brain in humans. The brain is now is know to respond to exercise much like a muscle -getting weaker with less exercise and stronger with regular exercise.
It has been shown through research that 35 percent of risk factors for developing dementia can be attributed to modifiable lifestyle choices, with exercise being a large portion of what we can control in our chances of getting dementia (4).
Although maintaining a healthy weight is part of that healthy lifestyle that helps prevent dementia, how you lose weight matters. In one study between three sets of people—individuals who lost weight through restrictive eating, people who lost weight through exercise, and a group that used a combination of the two—only the groups who had exercise as part of their weight loss regimen noted an improvement in brain function (2).
How exercise makes the difference in your brain is still not fully understood but it seems to improve brain function by:
- Increasing the size of the hippocampus (the part of your brain responsible for memory and learning)
- Increased BDNF (brain-derived neurotrophic factor), called fertilizer for the brain by John Ratey, MD because it is an important brain chemical in boosting memory and learning
- Increased blood flow to the brain
However, one factor that cannot be ignored when we talk about these brain benefits of exercise; the role stress plays in helping or limiting these brain benefits. Prolonged and unpredictable stress can interfere with brain cell growth, whereas mild stress (what we might call a “good challenge”), improves brain cell growth (3). We need to then carefully plan exercise so it is not stress producing, but rather to be a good challenge for the body and brain.
That means that the type, level and frequency of your exercise plan needs to be something you look forward to, not something that is boring or that is overwhelming. The place you choose to exercise in needs to help you feel confident, not self-conscious Exercise needs to fit into your life rather than make your life fit around your exercise plan. Finding that sweet spot takes careful planning, mindful awareness, and a good understanding about how much is enough exercise to get what you want from it. This balance is not only possible, it is essential if you are going to use exercise to help your brain function at its best for your whole life.
Keep Moving, Be Well,
1. Exercise and hippocampal neurogenesis: a dogma re-examined and lessons learned. Patrick Z. Liu, BA and Robin Nusslock. 2018
2. Why Exercise Is Good for Your Brain. Mylea Charvat, Ph.D. January 2019
3. Adult neurogenesis and physical activity. José R. Alonso. January 2018
4. .Dementia prevention, intervention, and care. Commission in Lancet. July 2017