A new study has found that dementia rates drop as certain aspects of lifestyles improve.
British researchers say they found a 25 percent decline among thousands of adults in England and Wales they tested between 1984 and 1994, and then again between 2008 and 2011.
Experts say that dementia is less common among people who are well educated and have good heart health.
As people continue to spend more time in school and control high blood pressure and cholesterol, rates should continue to go down.
The researchers say other high-income countries, like the United States, should experience a similar drop.
The study presents good news after advocacy groups and public health officials forecast a rise in the number of people with dementia and the cost of caring for them.
The study was published on Tuesday in The Lancet.