A long-term study published Wednesday found that people who steered clear of high blood pressure, diabetes and smoking in middle age lived about 13 more dementia-free years than those who carried all three risks. The finding gives a crisp number to a question that has long mattered to doctors and patients: how much later might dementia arrive if the blood vessels stay healthier in midlife?
NYU Langone Health researchers followed about 12,400 middle-aged U.S. participants for about 26 years and compared people with diabetes, hypertension and tobacco use with those who had none of those risks. The average age at the start was 56, just over half were women and about 25% were Black, and none showed signs of vascular cognitive impairment when the study began. Hypertension meant blood pressure of 140/90 mm Hg or higher.
The gap was large enough to show up in plain years, not just percentages. People with all three risk factors were estimated to have about 18 dementia-free years of life, compared with about 30 years for those with none. Their dementia risk climbed from 23% at age 55 to 37% at age 75, and by age 85 only 7% were dementia-free. Josef Coresh said the researchers wanted a simplified bottom-line message for the population, and that people with more risk factors had higher risk of both dementia and mortality.
That simple message lands because the mechanism is familiar. Healthy blood vessels support brain health, and the study focused on vascular health at a stage of life when damage can build quietly for years. Cynthia Carlsson said healthy blood vessels do not just protect against heart disease. Anna S. Nordvig said the three risks all contribute to small and large blood vessel disease in the brain, and that if brain tissue is not getting proper blood flow and nutrition, cognitive decline can follow.
The finding also sits inside a larger contradiction that patients hear all the time: there is no cure for vascular dementia or Alzheimer’s, but a major share of dementia may still be delayed or avoided. Coresh said about half of dementia is preventable through lifestyle changes, while Nordvig said she also watches high cholesterol, sleep apnea and obesity as critical risks. The practical takeaway is not that one healthy habit erases every danger, but that vascular health in midlife changes the odds for years to come. What the study does not yet answer is how much of that 13-year gap would remain if someone addressed only one of the three risks instead of all three.
