We hear a lot about the problems of teenagers who spend too much time online. But for older folks, screen time may offer a big benefit. Seniors who regularly use the internet are nearly half as likely to develop dementia as those who don’t use it as often, or who don’t use it at all, according to a new study.

A team of researchers from New York University found that people who used the internet at the start of their 8-year study had about half the risk of dementia as people who were not regular users.

Over 18,000 adults between the ages of 50 and 65 were included in the research. All were part of the Health and Retirement Study, which was conducted in combination with University of Michigan, the National Institute on Aging and the Social Security Administration. Each of the participants was asked this simple question:

    Do you regularly use the World Wide Web, or the Internet, for sending and receiving email or for any other purposes, such as making purchases, searching for information, or making travel reservations?

The researchers looked at how often participants were online ranging from not at all to more than eight hours a day.

Seniors who use the internet regularly are only half as likely to develop dementia as those who don’t use it as often, or who don’t use it at all

They found a couple of sweet spots. For example, seniors who were on the internet for around two hours or less a day had the lowest risk of dementia, compared with those that didn’t use the internet.

The difference in dementia risk between regular users and those who did not go online regularly did not vary by gender, levels of education, race or ethnicity.

“Online engagement may help to develop and maintain cognitive reserve, which can in turn compensate for brain aging and reduce the risk of dementia,” one of the authors, Virginia W. Chang, an associate professor of global public health at New York University’s School of Global Public Health, explained in a statement.

The Centers for Disease Control and Prevention estimates that around 6.2 million people 65 and older have Alzheimer’s disease, the most common form of dementia. That number is expected to continue to grow as baby boomers age.

Strides are being made in the development of new medications, and there are lifestyle changes you can make — in addition to spending time online — that may help to reduce the incidence or intensity of the disease. They include:

The study is published in the Journal of the American Geriatric Society.