A twin study from Great Britain has shown that people with stronger legs often have stronger brains. The study represents the latest example in favor of a correlation between physical activity, muscular health and mental sharpness. It is largely believed that genetics, environment and lifestyle play a role when it comes to determining the health of the human brain.
Twin studies have proven to be largely useful in this type of research. By studying twins, researchers can often rule out factors of genetics and early home environment. Instead, researchers can pinpoint differences that have been caused more by one’s lifestyle.
According to senior lecturer in twin research at King’s College London Claire Steves, people with more powerful leg muscles tend to have stronger minds than people with weak leg muscles. People with strong legs are usually able to move around better than people with weak legs, giving them an advantage when it comes to aging, both from a physical and mental standpoint.
Steves suspected that legs, which contain the largest muscles in the human body, might be able to paint an accurate picture of one’s mental sharpness. With that expectation in mind, Steves began her research. Along with her colleagues, she studied 162 healthy female twins in their middle ages. Some of these twins were identical twins, but others were fraternal.
Rather than examining exercise habits, Steves focused solely on leg strength. This is because some people can maintain strong legs even with little exercise. The study wasn’t designed to see how exercise affects the brain. Instead, Steves wanted to focus exclusively on the impact leg strength has on the brain, regardless of exercise. Still, it should be noted that there was undoubtedly some correlation between leg strength and exercise habits.
Steves and her colleagues had the twin pairs complete a series of cognitive tests. Many of the identical twins also had their brains scanned. These findings were compared with the strength of their legs. The researchers found that those with the sturdiest legs typically maintained the sharpest minds. This was even true when the scientists controlled for lifestyle factors such as fatty diets, high blood pressure and blood sugar levels. Thus, it showed that strong leg genetics were associated with strong minds.
The twin who demonstrated more muscular power in terms of leg strength than their associated twin typically performed 18% better on memory and cognitive tests than the muscularly weaker twin. The twins who demonstrated better leg strength also showed remarkably larger brain volumes than the twins with weaker legs.
Steves believes that healthy muscles release certain biochemicals that travel to the brain in order to improve its cellular health. Sturdier muscles release a greater amount of biochemicals. Still, it was just one study, and the findings should be taken with a grain of salt. In the near future, Steves and her team plan to conduct more studies in order to obtain a better understanding of these theorized mechanisms. But if you have strong legs, you might be sporting a strong brain too.