A stroke can produce a decline in thinking and memory equivalent to aging eight years, according to a new study.

The findings, based on an analysis of data from more than 4,900 black and white stroke survivors over 65 years of age, indicated having had a stroke meant that their score on a 27-item test of memory and thinking speed had dropped as much as it would have if they had aged 7.9 years overnight, Medical News Today reports.

The research, published in the journal Stroke, was conducted by the University of Michigan U-M Medical School and School of Public Health in Ann Arbor.

"As we search for the key drivers of the known disparities in cognitive decline between blacks and whites, we focus here on the role of 'health shocks' such as stroke," said lead researcher Deborah Levine, M.D., assistant professor at U-M Medical School.

"Although we found that stroke does not explain the difference, these results show the amount of cognitive aging that stroke brings on, and therefore the importance of stroke prevention to reduce the risk of cognitive decline."

The researchers stressed the importance of taking steps to reduce the risk of a stroke, including:

• Controlling blood pressure and cholesterol.
• Stopping or avoiding smoking.
• Controlling blood sugar in diabetes.
• Maintaining physical activity.