Midlife Heart Health Could Mean 12 More Dementia-Free Years, Study Finds

Doctors have long known that high blood pressure, diabetes and smoking raise the risk of both heart disease and dementia. A large, long-running study published in Neurology Open Access is now putting a number on what that risk actually costs patients: years of life without dementia.

Tracking Thousands of Adults for Decades

Investigators drew on data from the Atherosclerosis Risk in Communities study, a long-term project following participants from four U.S. communities. The analysis included 12,409 people who were alive and free of dementia at age 55. The team assessed three vascular risk factors measured in the early 1990s: diabetes, hypertension and current smoking, and tracked participants for a median of more than 26 years, into their 80s and 90s, using cognitive testing, informant interviews and death records to determine who developed dementia, who died without it and when.

More Risk Factors, Fewer Healthy Years

Participants with all three vascular risk factors were far more likely to develop dementia than those with none, and they were also far more likely to die before dementia ever developed. Compared with people with none of the three risk factors, those with all three had roughly two and a half times the risk of developing dementia, and more than five times the risk of dying without ever developing it.

When investigators translated this into dementia-free survival years, the difference was stark. People with no vascular risk factors at age 55 could expect an average of about 30 years of life without dementia. Those with all three risk factors could expect about 17.5 years, a gap of roughly 12.6 years.

“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, M.D., Ph.D., 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.”

Why Dementia Rates Looked Lower in the Highest-Risk Group

One counterintuitive finding: by age 95, the cumulative rate of dementia was actually lower in the highest-risk group than in the lowest-risk group, even though their dementia hazard was higher throughout most of the follow-up period. Investigators attribute this to competing mortality. People with more vascular risk factors were dying at higher rates before dementia had a chance to develop, which lowered the overall dementia count in that group by the study’s end.

Differences by Sex and Race

The study also found meaningful differences across groups. Women with all three risk factors lived a dementia-free average of 18.1 years, compared with 16.6 years for men. Black participants had shorter dementia-free survival than White participants, at 16 years versus 19.6 years, respectively.

A New Way to Talk About Prevention

The study’s authors say framing vascular risk in terms of years of healthy life, rather than abstract risk percentages, could give patients and doctors a clearer, more motivating way to approach prevention. Maintaining optimal blood pressure, blood sugar and smoking status in midlife was tied to as much as 12.6 additional years of life without dementia, a way of expressing risk the authors describe as more patient-centered than standard risk calculations.

“Hopefully these results will help encourage people to stop smoking, manage their blood sugar and manage their blood pressure in midlife,” said Coresh. “Of course, other healthy habits such as eating better and being more active are also important.”