In July 2019, the World Health Organization published a document of recommendations for reducing the risk of dementia.
Recommendation 1 refers to the positive effect of physical activity on reducing the risk of dementia.
What is the connection between physical activity and dementia?
Regular participation in physical activity over time has been found to be associated with a reduced risk of dementia.
In a large-scale study of risk factors for Alzheimer's disease in the UK, US and Europe, which examined seven specific risk factors, researchers found that physical activity had the most significant impact on reducing the risk of developing the disease. The researchers estimated that physical activity over time could lead to a reduction of up to 1.5 million cases per year in these countries.
However, other studies indicate that the effect of physical activity on brain function may be personally And it even differs from person to person.
It is recommended that a person find the nature, intensity, and frequency of physical activity that has a positive effect on them.
(The following are general recommendations only).
Why does physical activity have a positive effect on brain function?
A definitive answer to this question has not yet been found.
Several studies have suggested that physical activity leads to an increase in brain tissue.
There is a hypothesis that physical activity prevents degeneration of a brain structure called the hippocampus, which is known to play an important role in memory functions. One study showed that aerobic physical activity is accompanied by an increase in BDNF (a substance produced in the brain and affecting its development) and an increase in the volume of the hippocampus.
Other hypotheses relate to the possible effects of physical activity on increasing blood flow to the brain, increasing the production of neurotransmitters in the nervous system, alleviating inflammatory processes, or creating changes in the activity of certain genes.
In addition, physical activity also has a beneficial effect on the brain indirectly.
For example, an impact on risk factors for cardiopulmonary diseases, hypertension, insulin resistance, high cholesterol levels, strengthening the immune system, and more.
What is the most appropriate activity to reduce the risk of dementia?
In the literature, you can find recommendations for aerobic exercise, that is, activity that leads to an increase in the rate of heart and lung function.
High-intensity activity was found to have the most protective potential.
How long should you practice?
For people over 18, the World Health Organization's recommendations are:
High-intensity aerobic activity (running, cycling, playing squash) – at least 75 minutes per week
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Moderate-intensity aerobic activity (walking, dancing, vigorous swimming) – at least 150 minutes per week.
A long-term physical activity regimen with the frequency mentioned above has been found to be effective in reducing the risk of dementia for up to 25 years.
At what intensity is it recommended to exercise?
It is recommended that the physical activity be aerobic , so that there is an increase in the heart rate.
The duration of the activity should be at least 10 minutes continuously, but 30 minutes continuously is recommended.
In addition, for people aged 65+ who wish to benefit from additional health effects, it is recommended to perform muscle-strengthening exercise twice a week.
Sources:
Krell-Roesch, J. et al. (2018). Leisure-Time Physical Activity and the Risk of Incident Dementia: The Mayo Clinic Study of Aging. Journal of Alzheimer's Disease , 63, 149–155
Livingston, G. et al. (2019). Dementia prevention, intervention, and care: 2020 report of the Lancet Commission. Lancet, 396, 413-446.
Mortimer, JA & Stern, Y. (2019). Physical exercise and activity may be important in reducing dementia risk at any age. Neurology, 92, 362-363.
Müller, P., Taubert, M. & Müller NG (2019). Physical Exercise as Personalized Medicine for Dementia Prevention? Frontiers in Physiology , 10, 1-5.
World Health Organization Guideline. (2019). Risk reduction of cognitive decline and dementia.
https://www.who.int/publications/i/item/risk-reduction-of-cognitive-decline-and-dementia.