3 Big Risk Factors for Dementia to Avoid

While there are a few risk factors for dementia that you can’t control — like age and family history — a growing body of research shows that there are several that can potentially be changed throughout life. And a new study suggests that three of these so-called modifiable risk factors may have a big impact on an aging brain.

Diabetes, alcohol consumption (measured by frequency) and exposure to air pollution are the most harmful modifiable risk factors for dementia out of 15 that were studied in a new report published in the journal Nature Communications. A team of researchers examined brain scans of nearly 40,000 UK Biobank participants and found that parts of the brain associated with Alzheimer’s disease, the most common form of dementia, that are more prone to earlier and accelerated aging were most affected by these three factors.

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“We know that a constellation of brain regions degenerates earlier in aging, and in this new study we have shown that these specific parts of the brain are most vulnerable to diabetes, traffic-related air pollution — increasingly a major player in dementia — and alcohol, of all the common risk factors for dementia,” study coauthor Gwenaëlle Douaud, an associate professor at the University of Oxford, said in a statement.

Other known modifiable risk factors studied were blood pressure, cholesterol, weight, smoking, depression, inflammation, hearing, sleep, socialization, diet, physical activity and education.

A closer look at the big three

The study findings are not surprising, says Andrew Bender, a neuroimaging researcher at the Cleveland Clinic Lou Ruvo Center for Brain Health. 

Excessive alcohol use — defined as more than 21 drinks weekly — is among the 12 modifiable risk factors for dementia noted in a 2020 report published by the Lancet Commission. The Centers for Disease Control and Prevention (CDC) says that over time, too much alcohol can lead to learning and memory problems, including dementia.

And Bender, who was not involved in the latest study, says “diabetes is a really well studied and well known risk factor.” If diabetes is not well controlled and too much sugar remains in the blood, it can damage the organs over time, including the brain, explains the Alzheimer’s Association. High blood sugar is also linked to inflammation and cardiovascular disease — both of which can contribute to declining brain health.

Research on the health effects of air pollution is newer, but has been accumulating in recent years. A 2023 study published in JAMA Internal Medicine looked at data from more than 27,000 adults older than 50 and found that those who went on to develop dementia were more likely to live in places with higher levels of fine particulate matter. This type of air pollution can come from vehicles and factories, though in this particular study, fine particulate matter from agriculture and wildfires was specifically associated with an increased risk of dementia.