More than 57 million people are living with dementia globally. We previously discussed findings from the 2024 Lancet Commission on Dementia Prevention, Intervention and Care, suggesting that fully addressing 14 lifestyle risk factors may prevent up to 45% of dementia cases [1]. We also discussed the 2019 World Health Organization (WHO) report on lifestyle interventions for preventing cognitive decline and dementia. Here, we summarize the updated WHO guidelines on reducing the risk of cognitive decline and dementia, published in July 2026 [2].
People with higher levels of education and/or greater cognitive stimulation at work have a lower risk of developing dementia [3]. To reduce the risk of cognitive decline and/or dementia, the WHO recommends cognitive training or cognitive stimulation for older adults with normal cognition or mild cognitive impairment [2]. Cognitive training refers to repetitive cognitive exercise or task that stimulates specific cognitive functions. Cognitive stimulation refers to structured activities in a group or social setting, or everyday activities people can undertake themselves that enhance general cognitive function, such as reading, storytelling, and playing games or musical instruments.
Social participation is associated with good health and well-being, while social isolation is a risk factor for many conditions, including heart disease, depression, and dementia [4]. Social interactions may protect brain health by increasing brain volume and decreasing stress [5]. To reduce the risk of cognitive decline and/or dementia, the WHO recommends social activity interventions in adults with normal cognition or mild cognitive impairment [2].
Being physically active is associated with better cognition and lower dementia risk [6]. Physical activity benefits brain health by reducing chronic inflammation, improving blood flow, increasing the release of a protein that is very good for brain cells [7], and improving cardiovascular and metabolic health [8; 9]. To reduce the risk of cognitive decline, the WHO recommends physical activity for adults with normal cognition as well as those with mild cognitive impairment [2]. The WHO recommends adults get 150 to 300 minutes of moderate-intensity aerobic physical activity (or 75 to 150 minutes of vigorous-intensity physical activity) every week, along with at least two days a week of muscle-strengthening activities [10].
Heavy drinking is associated with many health risks, including cognitive impairment and dementia [1]. Emerging evidence suggests there may be no level of alcohol consumption that is risk-free for health [2; 11]. To reduce the risk of cognitive decline and/or dementia, the WHO recommends interventions aimed at reducing or stopping harmful drinking, including providing support to people with alcohol dependence [2].
Cigarettes and cigarette smoke contain more than 4,700 chemical compounds, including some that are highly toxic [12]. There is no safe level of exposure to tobacco. New evidence suggests that midlife cigarette smoking appears to be a stronger risk factor for dementia than smoking in late life [1]. To reduce the risk of cognitive decline and dementia, the WHO recommends tobacco cessation interventions (behavioral and/or pharmacological) to adults who use tobacco [2]. Non-smokers should also avoid exposure to tobacco smoke.
Healthy, balanced diets, like the Mediterranean diet, the Dietary Approach to Stop Hypertension (DASH) diet, and the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet, are associated with better cognitive health [13]. To reduce the risk of cognitive decline and/or dementia, the WHO recommends a healthy balanced diet in people with normal cognition or mild cognitive impairment [2]. Healthy balanced diets have high amounts of fruits, vegetables, whole grains, nuts, and legumes, while limiting red meat, saturated fats, and sugary foods.
The WHO recommends against the use of supplements containing vitamins B and E, omega-3 polyunsaturated fatty acids, and multivitamins/minerals in the absence of a diganosed deficiency, for the purpose reducing the risk of cognitive decline and/or dementia [2]. This recommendation was made by the WHO because of potential unexpected harmful effects of supplements that may outweight any potential benefits.
Higher central obesity, measured by waist circumference or waist-to-hip ratio, was associated with a greater risk of cognitive impairment and dementia based on an analysis that included a total of over five million people across 16 studies [14]. Obesity may increase the risk of dementia by increasing inflammation, vascular damage, and metabolic disruptions [15]. To reduce the risk of cognitive decline and/or dementia, the WHO recommends interventions for reducing midlife overweight/obesity, including dietary restriction [2].
People with type 2 diabetes have a significantly higher risk of developing dementia compared to those without diabetes [1]. Type 2 diabetes and dementia share some characteristics, such as impaired insulin signaling, altered brain metabolism, vascular complications, inflammation, and oxidative stress [16]. To reduce the risk of cognitive decline and/or dementia, the WHO recommends management of diabetes in people with diabetes [2]. A healthy diet, exercise, and weight control are the first steps of diabetes management, followed by medication(s).
Having hypertension (high blood pressure) in midlife increases the risk of cognitive impairment, vascular dementia, and Alzheimer’s disease [1; 17]. To reduce the risk of cognitive decline and/or dementia, the WHO recommends management of hypertension in people with hypertension [2]. Hypertension can be managed through lifestyle changes, such as healthy eating, low salt intake, physical activity, and weight control, as well as with medications.
Dyslipidemia is a metabolic disorder characterized by abnormal levels of lipids in the blood and is associated with cardiovascular diseases. High levels of low density lipoprotein (LDL) cholesterol in midlife is also associated with a higher risk of dementia [1; 18]. To reduce the risk of cognitive decline and/or dementia, the WHO recommends management of dyslipidemia in middle-aged people with dyslipidemia [2]. The most common lifestyle approaches to manage dyslipidemia include weight loss and decreasing dietary saturated fats (e.g., meat intake). Dyslipidemia is often managed with medications, including statins.
Mechanisms linking hearing loss to cognitive decline include social isolation, increased cognitive load, depression, and other pathologies [2]. To reduce the risk of cognitive decline and/or dementia, the WHO recommends hearing aids for adults with hearing loss [2]. An analysis of four studies reported that people with hearing loss who used hearing aids had a significantly lower risk of cognitive decline and dementia [19]. Primary prevention is also essential, including reducing exposure to loud sounds.
Menopausal hormone therapy is approved for the treatment of menopausal symptoms such as hot flashes [20]. In women over the age of 65, estrogen-containing menopausal hormone therapy increased the risk of cognitive impairment and dementia [21]. Thus, the WHO recommends against using menopausal hormone therapy specifically for reducing the risk of cognitive decline and/or dementia in postmenopausal women 65 years and older [2]. The WHO Guideline Development Group concluded that there is insufficient evidence to advise for or against the use of menopausal hormone therapy in women below 65 years old for the purpose of reducing the risk of cognitive decline or dementia.
Many studies have shown that air pollution, including particles with diameters less than 2.5 microns, referred to as PM2.5, is a risk factor for dementia and cognitive impairment [22]. PM2.5 can enter the brain and trigger inflammation and oxidative stress [2]. The WHO recommends reducing exposure to household air pollution as well as ambient air pollution (especially PM2.5) to reduce the risk of cognitive decline and/or dementia [2]. Although air pollution cannot be entirely avoided, there are steps you can take to reduce your exposure, such as monitoring air pollution levels online or with apps and stay indoors on days with particularly high air pollution. You can also limit exposure to car exhaust by closing vents and windows while driving in heavy traffic.
There is now a strong body of evidence from large clinical trials that addressing multiple lifestyle risk factors (e.g., diet, physical activity, cognitive activity, and management of cardiovascular/metabolic risk factors) can improve cognitive function in older adults at risk of cognitive decline and dementia. Examples include the original FINGER trial from Finland [23], the US POINTER trial from the US [24], the LatAM-FINGERS trial from Latin America [25], and others. To reduce the risk of cognitive decline and/or dementia, the WHO recommends tailored multidomain interventions [2]. By “tailored”, the multidomain interventions should address risk factors that are present in the individual, while aligning with cultural and socioeconomic factors to maximize feasibility, adherence, and effectiveness.
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The latest WHO report is great news in that there are concrete steps you can take to reduce your risk of cognitive decline and dementia.
Yuko Hara, PhD, is Director of Aging and Alzheimer's Prevention at the Alzheimer's Drug Discovery Foundation. Dr. Hara was previously an Assistant Professor in Neuroscience at the Icahn School of Medicine at Mount Sinai, where she remains an adjunct faculty member. Her research focused on brain aging, specifically how estrogens and reproductive aging influence the aging brain's synapses and mitochondria. She earned a doctorate in neurology and neuroscience at Weill Graduate School of Medical Sciences of Cornell University and a bachelor's degree in biology from Cornell University, with additional study at Keio University in Japan. Dr. Hara has authored numerous peer-reviewed publications, including articles in PNAS and Journal of Neuroscience.
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