It’s true that people are living longer in the US, but are their minds staying healthy, too? Yes, according to a new study published by the medical journal Alzheimer’s & Dementia. The research states that brain health is improving in aging people in the US. Researchers studied people over age 69 in 1993 and compared that data with a similar study of people in 2002. They discovered that cognitive impairment dropped almost four percentage points.

That number may seem small, but it correlates to hundreds of thousands of people whose brains are healthier—and it indicates that overall risk for dementia may be dropping among older Americans.

So the question is: why? Are aging Americans exercising more, smoking less, or seeing their physicians more often? Yes, and these factors contribute to healthier brains. But keeping your mind active is the real key, according to the lead author of the study, Dr. Kenneth Langa. Formal education, reading and talking with friends are important, but so is “staying connected with the world through volunteering and social networks.”

Staying connected through volunteering is not only good for the community—it’s good for your brain, too.