Nearly half of all dementia cases are linked to risk factors you can actually change. A 2024 Lancet Commission report identified 14 modifiable factors, from hearing loss and high cholesterol to physical inactivity and social isolation, that collectively drive a substantial share of dementia worldwide. Whether you’re trying to lower your own risk, slow early cognitive decline, or support someone already living with dementia, the most effective strategies combine diet, exercise, social and mental engagement, sensory health, and practical changes to everyday life.
The MIND Diet for Brain Health
The MIND diet, developed specifically with cognitive decline in mind, blends elements of the Mediterranean and DASH diets into a pattern focused on foods that protect brain function. It emphasizes leafy greens, berries, nuts, whole grains, fish, and olive oil while limiting red meat, butter, cheese, fried food, and sweets.
The specific targets are straightforward: at least three servings of whole grains a day, six or more servings of green leafy vegetables per week, five servings of nuts per week, four meals with beans, two servings of berries, two meals with poultry, and at least one meal with fish. Olive oil should be your primary cooking fat. On the flip side, keep red meat under four servings a week, pastries and sweets under five, and cheese and fried foods to less than once a week. Butter or margarine stays below a tablespoon a day.
You don’t need to follow every guideline perfectly. Research from Harvard’s School of Public Health suggests that even moderate adherence to the MIND diet is associated with slower cognitive decline compared to a typical Western diet.
Omega-3 Fats and Supplements
Among individual nutrients, omega-3 fatty acids have the strongest evidence base for cognitive protection. A large analysis pooling 48 studies with over 103,000 participants found that dietary omega-3 intake lowered the risk of dementia or cognitive decline by roughly 20%. The benefit was driven primarily by DHA, the type of omega-3 most concentrated in the brain and found abundantly in fatty fish like salmon, mackerel, and sardines.
The relationship appears to be dose-dependent. Each additional 0.1 grams per day of DHA or EPA (the two main omega-3s in fish) was linked to an 8 to 10 percent lower risk of cognitive decline. In one cohort study, long-term omega-3 supplement users had a 64% reduced risk of Alzheimer’s disease compared to non-users. That’s a striking number, though it comes from an observational study, meaning it can’t prove the supplements alone caused the benefit. Still, eating fatty fish two or more times a week, or taking a fish oil supplement if you don’t eat fish, is a reasonable and low-risk strategy.
Exercise and Cognitive Function
Aerobic exercise is one of the most consistently supported interventions for slowing cognitive decline. In a controlled trial published in JAMA Neurology, adults with mild cognitive impairment who exercised at a moderate-to-vigorous intensity (75 to 85 percent of their maximum heart rate) for 45 to 60 minutes a day, four days a week, showed measurable improvements in cognitive function compared to a stretching-only control group.
That’s a substantial time commitment, and not everyone needs to start there. Most guidelines recommend at least 150 minutes per week of moderate aerobic activity, things like brisk walking, cycling, or swimming. The key is getting your heart rate up consistently over time. Exercise increases blood flow to the brain, reduces inflammation, and promotes the growth of new connections between brain cells. For people already experiencing memory problems, it’s one of the few interventions that can genuinely slow the trajectory.
Treating Hearing and Vision Loss
This is one of the most underappreciated factors in dementia risk. Hearing loss forces the brain to devote more resources to processing sound, leaving less capacity for memory and thinking. It also tends to pull people out of conversations and social situations, compounding the problem through isolation.
The evidence for treating it is compelling. An NIH-funded trial found that among people at higher risk for dementia, those who received hearing aids experienced a nearly 50% reduction in the rate of cognitive decline over three years compared to a control group. That’s a larger effect than most medications can offer.
The 2024 Lancet Commission also added untreated vision loss as a newly confirmed risk factor for dementia. Getting regular eye and hearing exams, and actually using corrective devices when prescribed, is one of the simplest and most impactful things you can do.
Cognitive Stimulation and Social Activity
For people already living with dementia, cognitive stimulation therapy is one of the best-studied non-drug approaches. It involves structured activities like word games, puzzles, music, discussions about current events, and creative projects. A Cochrane review found that sessions lasting about 45 minutes, held at least twice a week, produced the clearest cognitive benefits, particularly for people in the mild stages of dementia.
You don’t necessarily need a formal program. Regular conversation, card games, jigsaw puzzles, singing along to familiar music, and even cooking together all provide meaningful mental engagement. The social component matters as much as the cognitive one. Social isolation is itself a recognized risk factor for dementia, and activities that combine thinking with human connection deliver a double benefit.
Medical Treatments for Alzheimer’s
A new class of medications can now target one of the underlying causes of Alzheimer’s disease: the buildup of amyloid plaques in the brain. The FDA has approved treatments like donanemab (sold as Kisunla), which works by clearing these plaques. These drugs are designed for people in the early stages, specifically those with mild cognitive impairment or mild dementia who have confirmed amyloid buildup on a brain scan.
These medications slow the progression of the disease rather than reversing it, and they carry real risks including brain swelling and bleeding that require regular monitoring with MRI scans. They’re not appropriate for everyone with dementia, and eligibility requires specialized testing. But for people who qualify and catch the disease early, they represent the first treatments that address the biology of Alzheimer’s rather than just managing symptoms.
Other Risk Factors Worth Addressing
Beyond diet, exercise, and sensory health, the Lancet Commission’s full list of modifiable risk factors includes high blood pressure, smoking, obesity, diabetes, excessive alcohol consumption (more than 12 standard US drinks per week), depression, low educational attainment, traumatic brain injury, air pollution, and high LDL cholesterol. You don’t need to tackle all 14 at once. Managing blood pressure and blood sugar, staying physically active, maintaining social connections, and avoiding smoking and heavy drinking cover a large portion of the preventable risk.
Making the Home Safer and Calmer
For someone already living with dementia, the physical environment matters more than most people realize. Confusion, agitation, and falls are often triggered by a space that’s hard to navigate. A few targeted changes can make a real difference.
Mark stair edges with brightly colored tape so each step is clearly visible. Use simple signs or picture labels on doors to identify the bathroom, bedroom, and kitchen. Paint walls a lighter color than the floor to create visual contrast, and avoid busy wallpaper patterns that can be disorienting. Install nightlights or automatic light sensors in hallways and bathrooms. Put nonskid strips in the tub and on uncarpeted bathroom floors, and add grab bars near the toilet and in the shower, choosing a color that contrasts with the wall so they’re easy to spot.
A few less obvious changes help too. Limit the number of mirrors in the home, since reflections can confuse or frighten someone with dementia. Place decals at eye level on glass doors and large windows. Pad or remove furniture with sharp corners. These modifications are inexpensive and can prevent injuries while reducing the anxiety that unfamiliar or confusing surroundings create.