Thanks twins

massai jumpingCan building muscle strengthen your mind? Fitter legs were strongly linked to fitter brains in a recent study. Because twins are so alike, comparing twins from the same pair can be useful in medical research.

Just in case my legs weaken in a few years and I forget, I’m keeping some highlights from a NYT article about stronger legs being linked to a stronger mind.

Muscular power is widely accepted as a marker of healthy aging. …scientists looked for twins who, 10 years previously, had completed extensive computerized examinations of their memory and thinking abilities, as well as assessments of their metabolic health and leg-muscle power, which measure muscles’ force and speed.

The scientists focused on the twins’ muscles rather than their exercise habits largely because the power measures were objective.

The scientists then asked the twins to visit a laboratory and repeat the cognitive tests. Twenty of the identical twin pairs also completed brain-imaging scans.Then the researchers compared leg power 10 years earlier with changes in brain function over the same time period.

They found that of the 324 twins, those who had had the sturdiest legs a decade ago showed the least fall-off in thinking skills, even when the scientists controlled for such factors as fatty diets, high blood pressure and shaky blood-sugar control.

The differences in thinking skills were particularly striking within twin pairs. If one twin had been more powerful than the other 10 years before, she tended to be a much better thinker now. In fact, on average, a muscularly powerful twin now performed about 18 percent better on memory and other cognitive tests than her weaker sister.

Similarly, in the brain imaging of the identical twins, if one genetically identical twin had had sturdier legs than the other at the start of the study, she now displayed significantly more brain volume and fewer “empty spaces in the brain” than her weaker sister.

Of course, this study involved only a single snapshot of the brain health of middle-aged female twins. Over all, among both the identical and fraternal twins, fitter legs were strongly linked, 10 years later, to fitter brains. 

…the results imply that whatever your genetic make-up, building muscles can strengthen your mind.