No smoking, no diabetes, normal BP could add nearly 13 dementia-free years, study says

The study does not prove that avoiding these vascular risk factors causes the delay in dementia; it only shows an association.

“Our findings support prevention of risk factors developing in midlife as a strategy for delaying the onset of dementia and maintaining brain health,” said study author Josef Coresh, MD, PhD, of NYU Grossman School of Medicine in New York. “Finding ways to prevent or delay dementia is crucial as the population ages as treatments remain limited.”

The study involved 12,409 people with an average age of 56 who were free of dementia. People were assessed for three risk factors for dementia: high blood pressure, diabetes and smoking. High blood pressure was defined as blood pressure higher than 140/90 mmHg or the use of medication to lower blood pressure, read the American Academy of Neurology website.

The participants were followed for an average of 26 years. During that time, 3,008 developed dementia and 5,238 people died without developing dementia.

People who had none of the risk factors lived without developing dementia nearly 13 years longer than people with all three of the risk factors. People with no risk factors lived for an average of 30.1 years after the start of the study without dementia. People with all three risk factors lived for an average of 17.5 years without developing dementia.

Female participants lived longer than male participants without developing dementia, regardless of how many risk factors they had. Female participants with all three risk factors lived an average of 18.1 years without developing dementia, compared to 16.6 years for male participants.

Coresh noted, “Women more often reach older ages and therefore experience many cases of late-onset dementia.”

White participants lived longer than Black participants without developing dementia, no matter how many risk factors they had. White participants with all three risk factors lived an average of 19.6 years without developing dementia, compared to 16.0 years for Black participants.

“People with all three risk factors were more likely to develop dementia or die at earlier ages from other causes, leading to shorter overall survival and fewer years with their thinking and memory abilities intact,” Coresh said. “Hopefully these results will help encourage people to stop smoking, manage their blood sugar and manage their blood pressure in midlife. Of course, other healthy habits such as eating better and being more active are also important.”

A limitation of the study was that the assessment of risk factors happened once, so it focused on long-term outcomes after one assessment, not changes over time.

The study was supported by the National Institutes of Health and the National Natural Science Foundation of China.