Scientists believe both genetic and lifestyle factors help determine an individual’s risk of developing dementia.

Following a healthy lifestyle, including eating a plant-based diet and exercising regularly, may help lower the risk of developing dementia — even among people with a high genetic risk for dementia, according to a study published online Sunday in the Journal of the American Medical Association (JAMA) and presented Monday at the Alzheimer’s Association International Conference (AAIC).

Specifically, the study found that people with a high genetic risk were about a third less likely to develop dementia if they followed a healthy lifestyle than if they didn’t.

About 5 million people in the United States have some form of dementia, including Alzheimer’s disease, its most common form, according to the Centers for Disease Control and Prevention (CDC). There is currently no cure for the condition.

Scientists believe both genetic and lifestyle factors help determine an individual’s risk of developing dementia. But past studies that have tried to figure out just how much a healthy lifestyle might reduce the risk in people with a high genetic risk have produced inconsistent findings.

This new study is the first one that has been able to identify the extent to which a healthy lifestyle may offset the genetic risk of the disease, say its authors.

“Our findings are exciting because they show that we can take action to try to offset our genetic risk for dementia,” says Elzbieta Kuzma, one of the study’s authors and a research fellow at the University of Exeter, in a released statement. “Sticking to a healthy lifestyle was associated with a reduced risk of dementia, regardless of the genetic risk.”

It’s also important to point out that even if a healthy lifestyle can prevent dementia in some people, it is not able to do so for everyone. Many individuals will develop the condition no matter how conscientious they are about the foods they eat or the hours they exercise each week.

Still, the study’s authors find the findings encouraging — and hopeful.

“This research delivers a really important message that undermines a fatalistic view of dementia,” says David Llewellyn, the study’s senior author and a professor of neuroepidemiology at the University of Exeter, in a released statement. “Some people believe it’s inevitable they’ll develop dementia because of their genetics. However, it appears that you may be able to substantially reduce your dementia risk by living a healthy lifestyle.”