Nearly half of dementia cases could potentially be delayed or prevented by addressing modifiable risk factors throughout your life. A 2024 Lancet Commission report identified 14 such factors, ranging from hearing loss and high blood pressure to physical inactivity and social isolation. The good news: most of the strongest protective strategies are things you can start doing today, and they compound over time.
Move at an Intensity That Challenges You
Exercise is one of the most consistently supported interventions for brain health, and the reason comes down to a protein called BDNF. Your brain produces this growth factor in response to aerobic exercise, and it helps maintain and build new connections between neurons, particularly in areas involved in memory.
Not all exercise triggers the same response. In a study comparing different intensities and durations, 40 minutes of vigorous cycling (at about 80% of maximum heart rate reserve) produced a significant BDNF increase in 100% of participants. Moderate intensity for 40 minutes still helped, with about 63% of participants seeing a meaningful rise. But shorter sessions of 20 minutes, even at high intensity, produced smaller and less reliable effects. The takeaway: duration matters as much as intensity. If you can sustain 30 to 40 minutes of exercise that gets you breathing hard, whether that’s brisk walking uphill, swimming, cycling, or jogging, you’re in the right range.
You don’t need to hit that level every day. Most research on cognitive protection points to 150 minutes per week of moderate activity, or about 75 minutes of vigorous activity, as a meaningful threshold.
Prioritize Deep Sleep
Your brain has its own waste-removal system, sometimes called the glymphatic system, that flushes out toxic proteins while you sleep. Two of those proteins, amyloid-beta and tau, are directly linked to Alzheimer’s disease when they accumulate. During deep sleep (stage 3, also called slow-wave sleep), the spaces between brain cells physically expand, allowing cerebrospinal fluid to flow more freely and carry waste away. At the same time, levels of the stress chemical norepinephrine drop, which relaxes the vessels that transport this fluid.
This cleaning cycle peaks during deep sleep specifically, not light sleep or REM. That distinction matters because deep sleep is the stage most vulnerable to disruption from alcohol, irregular schedules, and aging itself. Adults over 50 naturally spend less time in deep sleep, which makes protecting it even more important. Keeping a consistent sleep and wake time, avoiding alcohol close to bedtime, sleeping in a cool and dark room, and limiting caffeine after midday all help preserve your time in this critical stage. Seven to eight hours of total sleep gives your brain enough time to cycle through multiple rounds of deep sleep.
Eat for Your Brain, Not Just Your Heart
The MIND diet, developed specifically to support brain health, combines elements of the Mediterranean and DASH diets with an emphasis on foods linked to slower cognitive decline. The targets are straightforward:
- Green leafy vegetables: at least 6 servings per week
- Nuts: 5 servings per week
- Berries: 2 or more servings per week
- Fish: at least 1 serving per week
Berries stand out among fruits because of their high concentration of compounds that reduce inflammation and oxidative stress in brain tissue. Leafy greens like spinach, kale, and collards are rich in nutrients that support blood vessel health in the brain. You don’t need to overhaul your entire diet at once. Even partial adherence to the MIND pattern has been associated with slower rates of cognitive decline compared to a typical Western diet.
Omega-3 fatty acids deserve special mention. A large meta-analysis of 58 studies found that omega-3 supplementation improved performance across multiple cognitive domains, including attention, memory, language, and overall cognitive ability. The analysis measured effects per 2,000 mg per day of omega-3s, a dose achievable through a combination of fatty fish (salmon, sardines, mackerel) a few times per week and a supplement if needed.
Manage Blood Pressure and Metabolic Health
High blood pressure damages the small blood vessels that feed your brain, and this damage accumulates silently over decades. Data from the SPRINT MIND trial suggests that maintaining systolic blood pressure (the top number) within 110 to 140 mm Hg over time may be beneficial for dementia prevention. That range is lower than what many people consider “normal enough,” and it highlights why blood pressure management in midlife, not just after age 65, matters so much for long-term brain health.
The Lancet Commission’s 2024 report also flagged high LDL cholesterol as a newly confirmed risk factor for dementia, alongside diabetes and obesity. These conditions share a common thread: they all damage blood vessels and promote chronic inflammation, both of which accelerate brain aging. Staying on top of regular checkups, maintaining a healthy weight, and addressing metabolic issues early gives your brain the clean, efficient blood supply it depends on.
Stay Socially Connected
Social isolation doesn’t just feel bad. It physically shrinks your brain. A longitudinal neuroimaging study found that people who were more socially isolated had smaller hippocampal volumes, and the hippocampus is the brain’s primary memory center. The damage wasn’t limited to one area. Isolated individuals also showed reduced cortical thickness across multiple regions, including the precuneus, a structure that shows some of the earliest atrophy in Alzheimer’s disease.
What made this study particularly striking is that increasing isolation over time predicted additional grey matter loss, independent of other factors like age, education, and physical health. The relationship went in both directions: people who became more socially engaged showed less brain shrinkage. This means that reconnecting with friends, joining a group activity, volunteering, or simply maintaining regular contact with people you care about is a genuine neuroprotective strategy, not just a nice idea.
Keep Learning New Things
Your brain builds what researchers call cognitive reserve through intellectually stimulating activities over a lifetime. Think of it as a buffer: the more neural connections you’ve built, the more your brain can compensate when age-related changes begin. Research has found that reading, playing board games, playing musical instruments, and dancing are all associated with reduced dementia risk. Intellectual and social types of leisure activities appear to support multiple cognitive domains, including memory, language, attention, and executive function.
Education early in life provides a strong foundation, but the benefits of learning don’t expire. Taking up a new language, learning an instrument, or engaging with complex strategy games in your 50s, 60s, or 70s still builds new connections. The key is novelty and challenge. Activities that push you slightly beyond your current ability stimulate the brain more than passive entertainment or well-practiced routines.
Lower Chronic Stress
Cortisol, the body’s primary stress hormone, is useful in short bursts but toxic to the brain at chronically elevated levels. The hippocampus is especially vulnerable because it has a high density of cortisol receptors. A seven-year follow-up study of older adults found that chronically high cortisol levels were associated with smaller hippocampal volumes. Animal research confirms the mechanism: sustained cortisol exposure causes neurons in the hippocampus to physically shrink and lose connections.
Chronic stress, poor sleep, depression, and metabolic problems like obesity all contribute to elevated cortisol. Addressing any one of these creates a positive feedback loop that benefits the others. Regular physical activity lowers baseline cortisol levels. Consistent sleep restores healthy cortisol rhythms. Meditation, even 10 to 15 minutes daily, reduces the stress reactivity that keeps cortisol elevated. The goal isn’t eliminating stress entirely, which is impossible, but preventing it from becoming your body’s default state.
Protect Your Senses
Two of the 14 modifiable risk factors identified by the Lancet Commission are sensory: hearing loss and untreated vision loss. Hearing loss forces your brain to divert cognitive resources toward understanding speech, leaving fewer resources for memory and processing. It also tends to pull people away from social situations, compounding the isolation effect described above. Getting your hearing tested and using hearing aids when recommended is one of the simplest, most underappreciated steps you can take. The same logic applies to vision: correcting impairment with glasses, cataract surgery, or other treatments removes a source of chronic cognitive strain and keeps you engaged with the world around you.