Study: Running can help repair what junk food does to your brain

An unhealthy diet can damage not only your body but also your mood. However, there's good news, especially for those who enjoy running. Because, guess what? Regular running can repair much of the damage caused by junk food.

This is evident from new research from a university in Ireland.

Scientists have discovered that exercise helps partially reverse the negative effects of a high-fat and high-sugar diet . Running causes changes in the gut and rebalances important hormones. But if you really want to get the most out of your brain, you also need to pay attention to your diet.

The research, published in the scientific journal Brain Medicine , shows how running protects the brain against much of the food we eat in the West: lots of fat, lots of sugar and lots of processed products.

Under the supervision of Professor Yvonne Nolan, rats were fed either regular food or food containing fat and sugar for seven weeks. Half of the rats were also allowed to run freely in a running wheel. The animals that were allowed to exercise showed less depressed behavior, even when they ate junk food. According to the researchers, this shows that running helps restore healthy levels of gut substances and hormones.

But what happens in your body when you eat junk food? According to scientists, an unhealthy diet disrupts intestinal metabolism. Of the 175 substances tested, 100 changed in rats fed only food containing fat and sugar.

But running in a wheel restored that balance. Likewise, the substances that influence mood—anserine, indole-3-carboxylate, and deoxyinosine—which had decreased due to the unhealthy diet, increased again when the rats started running in the wheel.

The researchers also observed clear differences in the blood. Rats that ate unhealthy food and didn't exercise had higher levels of the hormones insulin and leptin, which play a role in fat storage and appetite. Exercise, on the other hand, lowered these levels.

However, running can't make up for everything, the researchers warn. The rats that ate junk food produced fewer new brain cells in the hippocampus, the part of the brain important for emotions and memory. With a healthy diet, this cell growth normally increases with exercise.

This means that nutrition determines how well your brain can benefit from exercise. So running certainly helps, but the effect is greater if you also eat healthily.