Key takeaways:

• Smoking, BP and diabetes status in midlife predicted the odds of developing dementia.
• The findings support preventive measures targeting these three vascular risk factors.

Not smoking, having normal BP and no diabetes may extend life without dementia by almost 13 years, a new study in Neurology Open Access shows.

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

Data derived from Hu J, et al. Neurology. 2026;doi:10.1212/WN9.0000000000000152.

Healio previously reported that addressing over a dozen risk factors, including depression, hypertension, obesity, vision loss and physical inactivity, could prevent or delay nearly half of dementia cases globally.

Prior studies assessing vascular health risk factors for dementia “have largely focused on etiologic associations or cumulative risk metrics, which do not directly capture how vascular health shapes the timing and duration of dementia-free survival years,” Coresh and colleagues wrote.

The researchers assessed 12,409 participants (56% women, 25.2% Black) from the Atherosclerosis Risk in Communities study, who were free of dementia at age 55 years and were followed over a median 26.3 years.

During that follow-up period, 3,008 participants developed dementia and 5,238 died free of dementia.

Three risk factors — current smoking, hypertension and diabetes — increased the risk for dementia (HR = 2.69; 95% CI, 1.94-3.73) and death without dementia (HR = 5.61; 95% CI, 4.67-6.74) vs. zero risk factors.

“Dementia-free survival years, which quantifies the expected duration of life lived cognitively intact,” decreased with more risk factors, dropping from 30.1 years (95% CI, 29.9-30.4) for zero risk factors to 26.3 years (95% CI, 26.1-26.6) for one risk factor, 21 years (95% CI, 20.5-21.4) for two risk factors and 17.5 years (95% CI, 16.3-18.7) for three factors, Coresh and colleagues reported.

Multiple biological mechanisms, “including chronic cerebrovascular injury, neuroinflammation triggered by vascular damages through hypertension and diabetes, and cumulative oxidative stress resulting from smoking,” may explain the associations, they added.

The outcomes varied for different populations. Women with three risk factors lived longer without dementia vs. men (18.1 vs. 16.6 years) and Black participants had fewer dementia-free survival years vs. white participants (16 vs. 19.6 years).

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

Coresh and colleagues acknowledged that limiting their assessment to three vascular risk factors “rather than a comprehensive cardiometabolic profile ... may not fully reflect clinical risk assessment but allows transparent translation of vascular burden into time-based outcomes.”

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