It’s not always possible to prevent or delay dementia. But experts are learning more about certain risk factors that may increase a person’s chances of developing the condition. A new study published Aug. 5 in Neurology Open Access, found that three factors are linked to living many more years without dementia: having normal blood pressure, being diabetes-free, and not smoking. When people in middle age and older—from ages 45 to 65—met all three conditions, they lived about 13 years longer than smokers who had high blood pressure and diabetes.
Dementia is a serious global health concern. It affects more than 57 million people worldwide, according to the World Health Organization, and is the seventh leading cause of death. In the U.S., 42% of Americans are at risk of developing dementia after age 55, a 2025 study found
The condition “dramatically affects people’s quality of life,” says Dr. Josef Coresh, founding director of the Optimal Aging Institute at NYU Langone and a senior investigator on the new study. “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.”
Health and behavior across the entire lifespan contribute to a person’s risk of eventually developing dementia. But the new findings suggest there are still opportunities in midlife to prevent or delay its onset, says Coresh. In your 40s, 50s, and 60s, “you have the potential to continue to reduce the risk” of cognitive decline and possibly gain more years living without dementia
What the new study found
The researchers analyzed data from more than 12,000 participants in a decades-long study that followed people for an average of 26 years. People were in middle age at the study’s start, and no one had dementia. Everyone was assessed for blood pressure, diabetes status, and whether they smoked. Though these are far from the only potential dementia risk factors, they’re “ some of the biggest, and we wanted to quantify how big the effect is,” says Coresh
The researchers found that people without these risk factors who hadn’t developed dementia went on to live nearly 13 years longer than those who smoked, had high blood pressure, and also had diabetes. “Each additional risk factor in midlife was associated with fewer expected years alive and free of dementia,” Dr. Jordan Weiss, an assistant professor at the Optimal Aging Institute at NYU Langone and study author, wrote in an email
Some groups of people had an even lower risk of developing dementia. Regardless of their number of risk factors, female participants without dementia lived longer than male participants, and white participants tended to spend more years without dementia than Black participants
The research does not prove that these three risk factors caused dementia—only that there is an association between not having them and living longer without the condition. Risk factor measurement was also only performed once, at the study’s onset, and doesn’t account for other lifestyle habits or behaviors during those 20 or so years. ”We don’t capture worsening over time, or smoking cessation, for example,” wrote Weiss
Other modifiable risk factors for dementia
In July 2026, the World Health Organization released updated guidelines on modifiable dementia risk factors, which included not smoking, managing diabetes and hypertension, and avoiding other health conditions and behaviors.
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“We’ve really found—over the last decade, even—an accumulation of many, many risk factors for dementia,” says Dr. Jeffrey Kaye, a professor of neurology and biomedical engineering at Oregon Health & Science University and director of the Layton Aging and Alzheimer’s Disease Center (who wasn’t involved in the new study)
Other potential ways to lower dementia risk include keeping your brain active, being social, and doing regular physical activity, as well as cutting back on alcohol, eating a balanced diet, maintaining a healthy weight and cholesterol levels, managing hearing loss, and reducing exposure to air pollution.The WHO guidelines estimated that by addressing all of these modifiable risk factors, 45% of dementia cases could be avoided
Some dementia cases can’t be prevented, however. Age, for example, is the single greatest risk factor: About one in 13 people from ages 65 to 84 have Alzheimer’s disease. Among people 85 and older, that rises to about one in three. A person’s genes, race, and gender also influence their odds of having dementia.
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A challenge for clinicians, says Kaye, is that studies like this look at an average, “and unfortunately, nobody’s average.” His hope is that in the future, experts will be able to move towards more individualized care, taking into account factors like a person’s genetics, health practices, and socioeconomic status to help mitigate a patient’s risk of cognitive decline in a sustained way
But this latest research underscores the thinking that behavior and overall health impact your brain with age, and dementia isn’t an inevitable part of getting older. “Trying to mitigate the risks of having certain conditions or health practices is really important,” says Kaye
