Dementia can be slowed, and in some cases symptoms can be partially reversed, through a combination of lifestyle changes, medical treatment, and addressing underlying health conditions. A 2024 Lancet Commission report identified 14 modifiable risk factors for dementia, meaning a significant portion of cases are influenced by things within your control. Whether you’re trying to slow early cognitive decline or reduce your risk of worsening symptoms, the evidence points to several practical strategies that make a measurable difference.
Conditions That Mimic Dementia
Before assuming cognitive decline is permanent, it’s worth knowing that several treatable medical conditions produce symptoms that look exactly like dementia. Depression can cause withdrawal, confusion, and memory problems in older adults. Medications that build up in the body over time, particularly in people taking multiple prescriptions, can cloud thinking and slow processing. Poor nutrition, especially deficiencies in vitamin B-12 and folate, directly affects brain function. Thyroid disorders, heart disease, and lung conditions that reduce oxygen delivery to the brain can all cause cognitive changes that improve once the underlying problem is treated.
These “reversible dementias” are one reason a thorough medical evaluation matters so much early on. If the cause turns out to be a vitamin deficiency or a medication interaction, the fix can be straightforward.
Exercise and Brain Volume
Physical activity is one of the most consistently supported interventions for cognitive health. Moderate-intensity aerobic exercise three days a week has been shown to increase the size of the hippocampus, the brain’s memory and learning center, by about 2%. That may sound small, but the hippocampus typically shrinks with age, so even maintaining its size represents a meaningful change.
The benefits extend beyond brain structure. In healthy but inactive middle-aged adults, brisk walking for 45 minutes five times a week produced significant improvements in attention and working memory. Among adults 65 and older without a genetic predisposition to Alzheimer’s, exercising four times a week cut dementia risk roughly in half compared to being sedentary.
The current U.S. guidelines recommend 150 minutes of moderate aerobic exercise per week (like brisk walking) or 75 minutes of vigorous exercise (like jogging or swimming laps). For someone already experiencing cognitive symptoms, even smaller amounts of regular movement appear to help, and the key is consistency rather than intensity.
The MIND Diet
Diet affects dementia risk more than most people realize. The MIND diet, developed specifically to support brain health, combines elements of the Mediterranean and DASH diets with a focus on foods linked to cognitive protection. Research from Rush University found that people with the highest adherence to this eating pattern had a 53% lower rate of Alzheimer’s disease.
The daily targets include three or more servings of whole grains and at least one serving of vegetables beyond leafy greens. Weekly goals are more specific: six or more servings of green leafy vegetables, five servings of nuts, four meals with beans, two servings of berries, two meals with poultry, and at least one meal with fish. Olive oil is the preferred cooking fat. The diet also limits red meat, butter, cheese, pastries, and fried food.
What’s notable is that even moderate adherence showed benefits. You don’t need to follow the plan perfectly to see results, which makes it more sustainable for most people.
Sleep and Brain Cleaning
During deep sleep, your brain runs a waste-clearing process that flushes out toxic proteins accumulated during waking hours. This system relies on slow-wave sleep, the deepest stage of the sleep cycle, when cerebrospinal fluid flows through brain tissue and drains metabolic waste into the body’s lymphatic system. When sleep is poor or fragmented, this cleanup process is disrupted, allowing harmful proteins to build up.
Prioritizing sleep quality means more than just logging enough hours. Keeping a consistent sleep schedule, treating sleep apnea if present, limiting alcohol (which suppresses deep sleep), and keeping the bedroom cool and dark all support the kind of restorative sleep your brain needs to maintain itself.
Cognitive Training That Works
Not all “brain training” is equally useful. A 20-year NIH-funded study tested three types of cognitive training in adults 65 and older: memory exercises, reasoning exercises, and visual speed-of-processing tasks. Only the speed training, which challenged participants to identify objects on a screen under increasingly difficult time pressure, was associated with a meaningful reduction in dementia diagnoses. Participants who completed speed training followed by booster sessions had a 25% lower rate of dementia diagnosis over two decades.
The training sessions lasted 60 to 75 minutes, twice a week, for five to six weeks. What made speed training different was that the difficulty adapted to each person’s performance, continually pushing the threshold of what their brain could handle. Standard memory games and crossword puzzles, while enjoyable, haven’t shown the same long-term protective effects in clinical trials.
Social engagement also matters. Social isolation is one of the 14 risk factors identified by the Lancet Commission, and regular interaction with others provides a natural form of complex cognitive stimulation.
Hearing and Vision Loss
Untreated sensory loss accelerates cognitive decline in a way that’s often underestimated. A clinical trial of nearly 1,000 adults ages 70 to 84 with substantial hearing loss found that hearing aids reduced the rate of cognitive decline by almost 50% over three years in people who were already at high risk for dementia. The likely explanation is that hearing loss forces the brain to redirect resources toward processing sound, leaving fewer resources for memory and thinking. It also contributes to social withdrawal, which compounds the problem.
The 2024 Lancet Commission update added untreated vision loss as a newly confirmed risk factor for dementia. Getting regular hearing and vision checks, and actually using corrective devices when prescribed, is one of the simplest and most effective interventions available.
Managing Vascular Health
Several of the strongest risk factors for dementia are the same ones that damage blood vessels: high blood pressure, diabetes, obesity, high LDL cholesterol, smoking, and excessive alcohol use. The brain depends on a healthy vascular system to deliver oxygen and nutrients, and vascular damage contributes to both Alzheimer’s disease and vascular dementia.
The Lancet Commission’s updated list specifically added high LDL cholesterol as a risk factor with compelling evidence. Managing blood pressure, blood sugar, and cholesterol through diet, exercise, and medication when needed protects the brain’s blood supply. Quitting smoking and keeping alcohol moderate (no more than 12 standard U.S. drinks per week, though less is better) further reduces risk.
Medications That Slow Decline
For people already diagnosed with Alzheimer’s disease, a newer class of treatments targets amyloid plaques in the brain. The FDA approved donanemab (brand name Kisunla) for adults with mild cognitive impairment or mild dementia from Alzheimer’s. In a clinical trial of over 1,700 patients, those receiving treatment showed a statistically significant reduction in cognitive and functional decline compared to placebo over 76 weeks. The treatment is given as an infusion every four weeks for up to 72 weeks.
These medications work best in early-stage disease and don’t reverse existing damage, but they represent the first treatments that address one of the underlying biological processes of Alzheimer’s rather than just managing symptoms. They carry risks, including brain swelling and bleeding, so they’re not appropriate for everyone.
Combining Multiple Strategies
The strongest evidence for slowing cognitive decline comes from addressing several risk factors simultaneously rather than focusing on just one. The landmark FINGER trial in Finland tested a two-year program combining diet improvement, exercise, cognitive training, and vascular risk monitoring in older adults at risk for dementia. Participants in the intervention group showed significantly better cognitive performance than those who received only general health advice.
This makes intuitive sense. Dementia rarely has a single cause, so a single intervention is unlikely to be enough. The practical takeaway is to work on multiple fronts: stay physically active, eat well, protect your hearing and vision, stay socially connected, manage blood pressure and cholesterol, sleep well, and seek treatment early if symptoms appear. Each of these individually offers modest protection. Together, they represent the most powerful tool available for preserving cognitive function.