Nearly 10 million new cases of dementia are diagnosed globally each year, according to the World Health Organization, making it one of the most feared health conditions associated with aging. While some risk factors such as genetics and age are beyond individual control, a growing body of research suggests that several lifestyle and health factors can be modified to significantly reduce the likelihood of developing dementia. In July 2026, the WHO released updated guidelines on modifiable risk factors, estimating that addressing them all could prevent 45% of dementia cases. The guidelines closely align with a 2024 update to the Lancet Commission on dementia prevention, which identified 14 modifiable risk factors for the condition.
Dementia is not a single disease but a term for brain changes that cause progressive loss of memory and impaired cognition. The most common form is Alzheimer's disease dementia, while vascular dementia is often caused by strokes. By age 85, one in three people is living with Alzheimer's. However, experts stress that dementia is not inevitable. Dr. Kristine Yaffe, a distinguished professor of psychiatry, neurology, and epidemiology at the University of California, San Francisco, and director of the Center for Population Brain Health, notes that while some cases are due to genetic bad luck, there is a message of hope. Changing certain behaviors can delay or minimize risk, she says, even for those with a family history of dementia or genetic predisposition.
One of the most important steps individuals can take is to prioritize heart health. High LDL cholesterol, obesity, hypertension, physical inactivity, and Type 2 diabetes together account for 14% of potentially modifiable dementia risk, according to the Lancet Commission. These factors are deeply interconnected: obesity increases the risk of developing high cholesterol, hypertension, and diabetes, while regular physical activity lowers the risk of all these conditions. A large longitudinal study published in the European Heart Journal found that people with higher blood levels of troponin I, a protein released when the heart experiences damage, were more likely to develop dementia later in life. A 2024 scientific statement from the American Heart Association, published in the journal Stroke, also linked heart failure, atrial fibrillation, and coronary heart disease to cognitive impairment and increased dementia risk. Dr. Joseph Coresh, founding director of the Optimal Aging Institute at NYU Grossman School of Medicine, emphasizes that vascular risk factors are very treatable, but treatment may need to begin early for maximum benefit. He recommends 150 minutes of moderate-intensity exercise per week, a heart-healthy diet rich in fruits, vegetables, whole grains, and lean proteins while limiting saturated fats, sugars, sodium, and ultra-processed foods, as well as regular check-ups to monitor blood pressure, cholesterol, and glucose levels.
Smoking and excessive alcohol consumption are two additional modifiable risk factors. Smoking accounts for 2% of modifiable dementia risk, and heavy alcohol consumption accounts for 1%, according to the Lancet commission. The recent WHO guidelines also urge adults to stop smoking and reduce alcohol intake. Both habits are linked to cardiovascular disease, which in turn affects brain health. Smoking impacts every organ in the body and contributes to an estimated 480,000 deaths annually in the United States. Excessive alcohol, defined by the American Heart Association as more than three drinks per day, can harm the liver and other organs, and also affects sleep and calorie intake. Dr. Coresh notes that alcohol can be a slippery slope, leading to injuries and other health problems. The recommended limits are no more than two alcoholic drinks per day for men and one drink per day for women.
Dr. Jason Karlawish, a professor of medicine, medical ethics, health policy, and neurology at the University of Pennsylvania Perelman School of Medicine, emphasizes that these risk factors bundle together nicely. Anything harmful to the heart, such as hypertension, obesity, diabetes, and high lipids, also turns out to be important for brain health. He stresses that not every case of dementia is preventable, and experts debate how many risk factors exist as the field evolves. However, the evidence is clear that adopting healthy habits across a person's lifespan can lower risk, even for those with a family history or genetic markers for Alzheimer's. The key is to start early and maintain these habits consistently, as the benefits extend to the whole body, including the brain.