Adults in midlife who kept their blood pressure normal, avoided diabetes and did not smoke lived on average nearly 13 more years without dementia than peers who had all three, according to a new analysis of a long-running US cohort. The study was published August 5, 2026 in Neurology Open Access, the journal of the American Academy of Neurology.
The three risk factors are recognizable and modifiable: high blood pressure, diabetes and smoking. The design is observational, so it shows an association rather than proof that fixing these factors causes the delay. But the size of the gap is unusual in dementia research.
What the researchers tracked
The team followed 12,409 adults in the Atherosclerosis Risk in Communities (ARIC) study who were around age 56 at baseline, over a median of about 26 years. During that time, 3,008 developed dementia and 5,238 died before ever receiving a dementia diagnosis, according to a summary from NYU Langone Health.
Participants with none of the three risk factors lived an average of about 30 years dementia-free from midlife. Those with all three lived about 17 years dementia-free, a difference of close to 13 years.
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The gap held across groups, but not evenly. Women with all three risk factors averaged 18.1 dementia-free years, compared with 16.6 for men. White participants with all three averaged 19.6 years, compared with 16.0 years for Black participants, differences the researchers linked to broader disparities in cardiovascular health and survival.
"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, in the announcement.
What the numbers mean in practice
The study defined high blood pressure as a reading above 140/90 mmHg or being on blood pressure medication. Current American Heart Association and American College of Cardiology guidance, reviewed for cardiovascular and renal risk in 2025, sets the treatment threshold lower, at 130/80 mmHg, with normal blood pressure defined as under 120/80.
Diabetes and prediabetes are identified in part by the A1C blood test, which reflects average blood sugar over the past three months. The National Institute of Diabetes and Digestive and Kidney Diseases defines an A1C below 5.7 percent as normal, 5.7 to 6.4 percent as prediabetes and 6.5 percent or higher as diabetes.
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For smoking, free coaching is available in every US state through the 1-800-QUIT-NOW quitline, which connects callers to trained counselors who help build a personalized quit plan. Spanish-language service runs on 1-855-DÉJELO-YA.
Not too late in midlife
The researchers frame midlife, roughly the mid-40s to late 60s, as a window when reducing risk can still shift the trajectory. "We've also come to appreciate that a lot of dementia is preventable, and a lot of the prevention potential relates to vascular risk factors," Coresh told Time magazine.
Not every expert reads the averages the same way. Jeffrey Kaye, professor of neurology and biomedical engineering at Oregon Health and Science University, who was not involved in the study, told Time that dementia risk is highly individual and shaped by genetics, health habits and social factors. "Unfortunately, nobody's average," he said.
The authors also flag a limitation. Risk factors were measured only once at baseline, so the analysis cannot show how quitting smoking or bringing blood pressure down later in life changes the picture. People with concerns about their own risk should discuss blood pressure, blood sugar and smoking with their doctor.
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This article is made and published by Jesper Bengtson, who may have used AI in the preparation.