That estimate is based on a new study that found a higher lifetime risk than previously thought: After age 55, people have up to a 4 in 10 chance of eventually developing dementia—if they live long enough.

Dementia cases in the U.S. are expected to double by 2060, with an estimated one million people diagnosed per year, according to a new study led by Johns Hopkins University and other institutions.

A new study estimates that up to 4 in 10 people over 55 could develop dementia, but experts share steps to lower the risk.