Many people who want to lose weight, build muscle or get healthier turn to diet and exercise, but we often only think of diet and exercise as affecting our physical health. A new study shows that diet and exercise can help our mental health too.

This new study which was published in the journal Neurology specifically looked at the mental health of older adults with an average age of 65. Two-thirds of the participants were female, and half of the participants were white while the other half was made up of minorities.

The participants were equally divided into four groups. One group had a 30-minute call with a health advisor but was told not to change their diet or exercise habits.

Another group was encouraged not to exercise but was put on the DASH diet. DASH stands for Dietary Approaches to Stop Hypertension. This is a heart-healthy diet that eliminates things like sweets, and salty and fatty foods. Instead, people eat whole grains, and fruits and vegetables.

One group was encouraged not to change their eating habits but exercised three times a week. For the first 3 months, this group did non-strenuous exercise at a cardiac rehab facility three times a week. They did a 10-minute warm up, and then they did low impact exercise like walking or riding a stationary bike. Then, for 3 months, this group kept exercising 3 times a week at home on their own. Research staff kept track of the compliance logs these participants filled out.

The last group combined the DASH diet with the exercise routine. All of the participants in all of the groups kept with the program for 6 months; nobody dropped out or failed to participate.

At the very beginning of the study, before the diet or exercise changes started, all of the participants took several tests including cognitive tests, a dietary assessment and a treadmill stress test. These tests were repeated after 6 months when the study ended.

The results showed that the participants who exercised has significant improvement in their executive functioning skills. These are the skills needed to do things like pay bills and take care of yourself. These skills were more improved in the people who exercised than the people who dieted, but the people who dieted and exercised had the biggest improvement. This group actually improved their mental age by 9 years in just 6 months!

There wasn’t any significant improvement in memory in any of the groups, but the study authors think that perhaps if the study had gone on longer, maybe 18 months, they might have seen improvement.

While additional studies are needed, if you want to improve your mental health, make a New Year’s resolution to go for a walk 3 times a week, and you might notice a change in just 6 months.