Brain Enhancement: Exercise Literally Makes It Grow Bigger

New York City Marathon in November 2017. A new study indicates that cardiovascular activity can actually increase a portion of the hippocampus. Eduardo Munoz Alvarez/Getty Images

There's no shortage of supplements promising to boost your brain power, but a new study indicates you don't have to turn to Ginkgo Biloba for mental health. Instead, exercising a few days a week could improve memory and slow the signs of aging.

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Research in lab animals has shown that physical activity can increase hippocampal size, but in humans, the results have been less compelling. So, scientists from Western Sydney University in Australia and the University of Manchester in the United Kingdom delved into how aerobic activity impacts this vital part of the brain, according to a release. The hippocampus helps us form memories and gradually shrinks as we age.

The team reviewed 14 clinical trials that included brain scans of 737 people before and after aerobic activity. The sample included a wide mix of healthy people, those with cognitive impairment like Alzheimer's disease as well as mental illnesses such as depression. People were 66 years old on average and participated in a variety of exercises including walking, treadmill running or riding a stationary bike. Studies ranged from three months to two years and looked at the effects of exercising two to five times a week.

After analyzing the data, researchers found that while exercise did not increase total volume of the hippocampus, it did seem to increase the region's left side. Psychiatrist Joseph Firth, lead study author, believes this new research offers the most compelling evidence about the benefits of exercise.

"When you exercise you produce a chemical called brain-derived neurotrophic factor, which may help to prevent age-related decline by reducing the deterioration of the brain," he said in a statement.

He believes that exercise is just another tool that can be used to prevent aging, like supplements or puzzles.

"Our data showed that, rather than actually increasing the size of the hippocampus per se, the main 'brain benefits' are due to aerobic exercise slowing down the deterioration in brain size. In other words, exercise can be seen as a maintenance program for the brain," he said.

Vietnamese bodybuilder working out in February 2017. A new study says that working out could help slow the effects of aging in our brains. HOANG DINH NAM/AFP/Getty Images

Aside from the typical aging, there is some evidence that exercise could actually help with Alzheimer's and dementia, though the diseases remain a mystery.

A study from July of this year showed that senior citizens who exercised regularly benefited from lower levels of the nutrient, choline in their brains. While we need this nutrient for our brains to function, research has shown that Alzheimer's patients typically have higher concentrations as a result of losing nerve cells. Those who exercised had stable levels of choline, indicating they also maintained nerve cells. Exercise has been shown to be beneficial even after an Alzheimer's diagnosis, improving brain function, according to a study from February.

As the researchers of this new study also note, while exercise can make your brain bigger, it prevents one thing from widening: your waistline.