In the 2024 update of the Lancet Commission on dementia prevention, intervention and care, 27 dementia experts examined decades of research from around the world.

The researchers identified 14 potentially modifiable risk factors that together were associated with an estimated 45% of dementia cases worldwide.

The Commission’s advice is simple: reduce risk factors as early as possible and keep them low for as long as possible. But it also emphasizes that it is never too early or too late to make changes that may reduce dementia risk.

So what are these 14 factors?

1. Less education

Education does more than prepare us for a career. Learning appears to help the brain build what scientists sometimes call cognitive reserve — essentially, greater resilience against changes in the brain later in life.

But this doesn’t mean your fate was determined by how many years you spent in school.

The Commission specifically points to the benefits of remaining cognitively active during midlife, even among people who received less formal education earlier in life.

Learning a language, playing an instrument, reading, taking classes, solving problems and mastering new skills are all ways of continuing to challenge the brain.

2. Hearing loss

This is one of the biggest and most overlooked findings.

Hearing loss was associated with about 7% of dementia cases worldwide in the Commission’s model, making it one of the largest potentially modifiable risk factors.

Why might hearing matter?

Difficulty hearing can reduce communication and social interaction. Listening also becomes more cognitively demanding when the brain has to constantly work to decipher incomplete sounds.

Importantly, evidence that treating hearing loss may reduce dementia risk has strengthened. The Commission recommends making hearing aids accessible to people who need them and protecting hearing from excessive noise.

So don’t simply dismiss hearing loss as a normal inconvenience of aging.

3. High LDL (“bad”) cholesterol

This was one of two new risk factors added in the 2024 report.

High LDL cholesterol beginning around age 40 was associated with about 7% of dementia cases in the Commission’s population model.

Most of us think about cholesterol in connection with heart attacks and strokes. The new report gives us another reason to pay attention to it.

The Commission recommends detecting and treating high LDL cholesterol beginning in midlife.

If you haven’t had your cholesterol checked recently, this is one more reason to bring it up at your next physical.

4. High blood pressure

What’s good for the heart is often good for the brain.

Years of high blood pressure can damage blood vessels throughout the body — including the delicate vascular system supplying the brain.

The Commission recommends preventing or treating hypertension and specifically suggests maintaining systolic blood pressure around 130 mm Hg or lower from age 40, when appropriate.

This is another reason your blood-pressure reading shouldn’t be something you ignore until you’re 70.

5. Physical inactivity

We often think about exercise in terms of weight, muscles or appearance.

Your brain belongs on that list too.

People who are physically active have a lower risk of developing dementia, according to the evidence reviewed by the Commission.

You don’t necessarily need to become a marathon runner. Walking, hiking, swimming, cycling, dancing, strength training and recreational sports all get the body moving.

The important thing is to make movement part of everyday life.

6. Diabetes

Diabetes affects much more than blood sugar.

Over time, it can damage blood vessels and is associated with increased risk of cardiovascular disease, stroke and dementia.

Maintaining a healthy weight, exercising, eating well and working with your healthcare provider to prevent or properly manage diabetes can therefore be an investment in both cardiovascular and brain health.

7. Obesity

Obesity in midlife is another potentially modifiable dementia risk factor.

And many of these factors are interconnected.

Regular physical activity, for example, can help with weight, blood pressure, blood sugar and cholesterol simultaneously. That’s an important point: you don’t necessarily need 14 separate strategies for these 14 risks.

One healthy habit may improve several of them at once.

8. Smoking

Add brain health to the very long list of reasons not to smoke.

Smoking damages blood vessels, increases cardiovascular disease and exposes the body to substances that contribute to inflammation and oxidative stress.

The encouraging news is that quitting still matters. The Commission notes new evidence suggesting that smoking cessation may reduce dementia risk.

9. Excessive alcohol consumption

Heavy alcohol consumption is associated with increased dementia risk.

The Lancet report specifically identifies excessive drinking — more than 21 UK units per week, equivalent to more than about 12 U.S. standard drinks — as a risk factor.

This doesn’t mean everyone who occasionally enjoys a glass of wine should panic. The concern here is high levels of alcohol consumption over time.

10. Depression

Depression isn’t simply a matter of mood. It is also associated with future dementia risk.

The relationship is complicated: depression may contribute to dementia risk, share underlying biological pathways with dementia, and in some cases appear during the early stages of cognitive disease.

Still, the Commission concludes that depression should be effectively treated and notes growing evidence that treatment may help reduce dementia risk.

Mental health is part of brain health.

11. Social isolation

This may be one of the easiest risk factors to underestimate.

Humans are social creatures, and regular interaction gives our brains an enormous amount of stimulation — conversation, emotion, memory, interpretation and problem solving.

Infrequent social contact was associated with about 5% of dementia cases in the Commission’s global model.

Maintaining friendships, spending time with family, joining groups, volunteering, taking classes or simply having regular conversations with other people may all be meaningful parts of healthy aging.

12. Traumatic brain injury

Protect your head.

Traumatic brain injury at any age is associated with greater dementia risk, and the Commission highlights growing evidence about repeated head impacts in contact sports.

Its recommendations are wonderfully practical: wear helmets when cycling, use appropriate protection in contact sports, reduce unnecessary high-impact collisions and take concussions seriously.

13. Air pollution

This one is harder to control individually.

Long-term exposure to air pollution is associated with dementia risk, and the Commission reports growing evidence that reducing pollution is linked with better cognitive outcomes.

That makes dementia prevention not only an individual responsibility but also a public-health issue involving cleaner air, transportation and environmental policy.

14. Untreated vision loss

This was the other new risk factor added in 2024.

Untreated vision loss in later life was estimated to account for about 2% of dementia cases in the Commission’s model.

The good news is that some causes of vision impairment are remarkably treatable.

The report cites research linking vision impairment with higher dementia risk and recommends making vision screening and treatment widely accessible.

So those eye exams aren’t just about reading smaller letters.