The Finnish Twin Cohort conducted a long-term follow-up study of 3,050 twins, revealing that midlife physical activity is associated with better cognition at old age. The researchers controlled for variables like midlife hypertension, smoking, sex, and obesity, allowing for the findings to be statistically independent. Based on this study, it appears that the benefits of physical activity on the brain and on cognition are not only focused on decreasing vascular risk factors.
The study revealed that the most inactive twins in the pairs had a notably higher risk of cognitive impairment. It appears that a moderate amount of physical activity—more than just strenuous walking—is sufficient for preserving and protecting memory. That being said, engaging in high amounts of exercise did not make the memory-protecting benefits any more potent than those experienced through a moderate amount of activity. The benefits to cognition reportedly took effect after an average of 25 years.
Scientists at the universities of Helsinki, Jyväskylä, and Turku conducted the study by using questionnaires to gather information on the twins between 1975 and 1981. The mean age for subjects in 1981 was 49. Cognition was measured by conducting validated telephone interviews between 1999 and 2015.
Evidence from various studies conclude that physical activity increases the amount of growth factors in the brain and improves synaptic plasticity.
Aging, along with traditional vascular risk factors such as hypercholesterolemia, obesity, elevated blood pressure, diabetes, and physical inactivity have been associated with dementia. Although studies have shown that those who are physically active through midlife have better cognition, it is still unclear precisely what amount of exercise is necessary to secure cognition and completely prevent dementia from occurring.
Iso-Markku, P., “Midlife physical activity is associated with better cognition in old age,” IOS Press web site, Sept 12 2016; http://www.iospress.nl/ios_news/midlife-physical-activity-is-associated-with-better-cognition-in-old-age/