Prevent dementia and Alzheimer's: 7 evidence-based things you can do in 2026

What does the Lancet Commission 2024 say about modifiable risk factors?

Since 2017, the Lancet Commission on dementia prevention, intervention and care has published periodic updates of the overall evidence for dementia prevention. In the 2024 update, the commission identified 14 modifiable risk factors that together can explain up to 45% of the global dementia burden. Livingston et al., The Lancet 2024 Alzheimer's Society UK

The 14 factors range from early childhood (education) through midlife (hearing loss, hypertension, obesity, alcohol, head trauma) to later life (smoking, depression, physical inactivity, diabetes, social isolation, air pollution, vision loss and high LDL cholesterol). The idea is a lifetime model: the earlier you act, the greater the cumulative protective effect. Livingston et al., The Lancet 2024 Alzheimer's Society UK

Blood pressure, hearing and LDL — the three strongest single factors

Untreated hypertension at the age of 40-60 is one of the best documented risk factors for later cognitive failure. High blood pressure damages the small blood vessels in the brain, reducing cerebral perfusion and increasing the risk of small infarcts that accumulate over time. Treatment goals of less than 130/80 mmHg in middle-aged people reduce both cardiovascular and cognitive risk. Alzheimer's Society UK World Health Organization

Hearing loss is surprising to many — but it is the single biggest factor in the Lancet model. The likely mechanism is that untreated hearing loss increases cognitive load (the brain uses more resources to interpret sound), reduces social interaction, and may accelerate brain atrophy. Hearing aids are one of the most cost-effective dementia prevention interventions we have. Alzheimer's Society UK World Health Organization

Exercise and cognitive reserve: what is the minimum dose?

Physical activity is one of the most robust protective factors against cognitive decline. The mechanism is threefold: exercise increases cerebral blood flow, stimulates BDNF (brain-derived neurotrophic factor), which supports neuroplasticity, and reduces inflammation — a key driver of neurodegeneration. World Health Organization PMID 25681666

Most studies point to 150 minutes of moderate activity per week as a threshold where the cognitive benefits begin to become apparent. Zone 2 training seems particularly relevant because it improves mitochondrial function and glucose metabolism in brain tissue. Strength training twice a week adds further protection through improved insulin sensitivity. World Health Organization PMID 25681666

Sleep and glymphatic clearance — why deep sleep protects the brain

During deep sleep (slow-wave sleep), the glymphatic system is activated — the brain's own cleaning system that removes metabolic waste products, including beta-amyloid and tau protein, which are the two central pathological proteins in Alzheimer's disease. Insufficient deep sleep means reduced glymphatic clearance and accumulation of neurotoxic proteins over time. PMID 25681666 PMID 31446007

Studies show that people who chronically sleep less than 6 hours per night have an increased risk of cognitive impairment. But quality is just as important as quantity: fragmented sleep with frequent awakenings is associated with increased amyloid accumulation on brain scans. Sleep apnea — which is widespread and often undiagnosed — is a particular concern because it both fragments sleep and causes intermittent hypoxia (lack of oxygen) in brain tissue. PMID 25681666 PMID 31446007

Diet, inflammation and metabolic coupling to the brain

The brain is a metabolically demanding organ — it uses 20-25% of the body's glucose, even though it only makes up 2% of body weight. Insulin resistance in the brain, often called 'type 3 diabetes' in the research literature, is a growing hypothesis for how metabolic dysfunction drives neurodegeneration. PMID 31446007 Sundhedsstyrelsen

The MIND (Mediterranean-DASH Intervention for Neurodegenerative Delay) diet combines elements of the Mediterranean and DASH diets and is specifically designed to protect cognitive function. Studies show that people with a high MIND score have a 30-50% lower risk of Alzheimer's. The key components are: green leafy vegetables, berries, nuts, whole grains, fish, poultry, olive oil and limited red meat, butter and sugar. PMID 31446007 Sundhedsstyrelsen

Social connection, cognitive stimulation and mental reserve

Social isolation is an independent risk factor in the Lancet model and is associated with increased dementia risk through several mechanisms: reduced cognitive stimulation, less physical activity, increased stress response and higher risk of depression — which itself is a separate risk factor. Sundhedsstyrelsen

Cognitive reserve building occurs throughout life. Formal education in childhood lays the foundation, but adults can continue to build reserve through complex cognitive activities: language learning, musical training, volunteering, or what researchers call 'cognitively demanding leisure activities'. The crucial thing is that the activity requires active problem solving, not passive consumption. Sundhedsstyrelsen

Social relationships are the third pillar. Regular social contact — even a few hours a week — is associated with lower dementia risk. The mechanism is probably the simultaneous activation of many cognitive domains: language, executive function, emotion regulation and memory. Sundhedsstyrelsen

What should you do first? A practical prioritization

With 14 modifiable risk factors, it can seem overwhelming. Fortunately, many of the interventions have overlapping effects—blood pressure treatment, exercise, and weight control improve both cardiometabolic and cognitive health. A practical prioritization can therefore start with the three things that provide the most for the effort. Sundhedsstyrelsen

First: Get your blood pressure and LDL cholesterol checked. If they are too high, treatment is one of the most evidence-based dementia prevention interventions. Next: Get a hearing test. Hearing loss is widespread after 50, often undiagnosed, and hearing aids are a simple solution with a proven cognitive effect. Third: Build a sustainable exercise routine — 30 minutes of daily walking has a measurable effect on brain health. Sundhedsstyrelsen