The 2024 Lancet report on dementia prevention and care identifies 14 key modifiable risk factors, emphasising that addressing these could prevent or delay nearly half of dementia cases. Efforts to reduce these risks include promoting education, regular physical activity, controlling health conditions like diabetes and hypertension, using hearing aids or correcting vision problems, maintaining a healthy diet and weight and encouraging social engagement and mental stimulation.

Here is a summarised list of these risk factors identified together with the report recommendations to mitigate or reduce these risks. A concise list can be found at the end of this article, along with insights on why nutrition should be a greater focus.

1. Low Education: Early educational opportunities are vital with access to primary and secondary education being crucial, as educational attainment in youth builds cognitive reserve, which can protect against dementia later.

Report Recommendations : The findings suggest that providing access to quality education for everyone and promote engaging, cognitively stimulating activities during midlife can safeguard cognitive health.

2. Hearing Loss: Untreated hearing impairment in midlife and later years is associated with a higher risk of dementia, partly due to increased social isolation and reduced cognitive engagement that can accompany hearing loss. Research included in the report suggests that every 10-decibel decrease in hearing ability could raise the risk by as much as 24%. The report also notes that severity matters; as hearing declines, dementia risk rises accordingly.

Report Recommendations: Hearing aids and early intervention can help reduce dementia risk associated with hearing impairment, particularly as hearing loss can lead to reduced stimulation of auditory and cognitive pathways. Addressing hearing loss through public health measures, such as making hearing aids more affordable and accessible, is among the recommended strategies to combat dementia globally.

3. Hypertension: Midlife hypertension (high blood pressure) is identified as a significant risk factor for dementia. Chronic high blood pressure can contribute to vascular damage and reduce blood flow to the brain, which can lead to cognitive impairment and increase dementia risk over time. The report highlights the importance of managing hypertension in midlife as part of a broader strategy to reduce dementia incidence globally.

Report Recommendations: Lowering blood pressure through lifestyle interventions (such as reducing salt intake, exercising regularly, and managing stress) and medication is emphasised as a preventive measure. The report highlights that consistent blood pressure control can have a protective effect on brain health, especially for individuals at risk of vascular dementia. Implementing public health policies to increase hypertension awareness and access to treatment is advocated as a potentially impactful approach to reducing dementia rates globally.

4. Smoking: Smoking is highlighted as a major modifiable risk factor for dementia, emphasising its detrimental effects on brain health. Smoking contributes to neurovascular damage, reduces blood flow to the brain, and increases the risk of cognitive decline. The report reinforces that smoking accelerates the aging of the brain, leading to an increased likelihood of dementia later in life. This connection is particularly concerning given the high global prevalence of smoking and its association with other health conditions like cardiovascular disease, which further compound dementia risk.

Report Recommendations: The report calls for policies aimed at reducing smoking rates, particularly in midlife, as a critical component of dementia prevention. Quitting smoking at any age is beneficial, but stopping earlier in life has the greatest protective effects on brain health. Public health measures such as smoking bans and smoking cessation programs are advocated as vital tools in reducing the global burden of dementia.

5. Obesity: Obesity in midlife is identified as a substantial risk factor for dementia, largely due to its impact on vascular and metabolic health. Obesity contributes to conditions such as high blood pressure, diabetes, and inflammation, all of which can impair blood flow to the brain and increase neurodegenerative risks. The report suggests that managing weight through a balanced diet and regular physical activity may help protect against dementia, especially if obesity is controlled in midlife before the onset of age-related cognitive decline.

Report Recommendations: It calls for public health policies to address obesity as a preventative strategy, including access to healthier foods, exercise programs, and education on maintaining a healthy weight. These measures could play a critical role in reducing the future burden of dementia worldwide.

6. Depression: Depression, particularly in midlife, is highlighted as a significant modifiable risk factor for dementia. The report explains that untreated depression can increase dementia risk by contributing to chronic stress, inflammation, and changes in brain structure and function. Depression is thought to weaken cognitive resilience, making the brain more vulnerable to neurodegenerative processes that may lead to dementia later in life.

Report Recommendations: The report distinguishes between depression that arises in midlife, which appears to increase dementia risk, and depression that occurs later in life, which may sometimes be a symptom of early-stage dementia rather than a causal factor. Addressing depression early through effective treatment and support is recommended as a strategy for potentially reducing dementia risk. The report advocates for mental health support and public health initiatives that improve access to mental health care as part of a comprehensive approach to dementia prevention.

7. Physical Inactivity: Physical inactivity is highlighted as one of the modifiable risk factors for dementia estimated to contribute to 6-7% of global dementia cases. Exercise promotes cardiovascular health, cerebral blood flow, and neurogenesis (growth of new neurons). Physical inactivity may lead to risk factors such as obesity, high blood pressure, and diabetes, which are also linked to cognitive decline. Engaging in regular physical activity helps reduce dementia risk by improving brain plasticity, reducing inflammation, and enhancing vascular health. Even moderate-intensity exercise (e.g., brisk walking, cycling) can have significant benefits.

Report Recommendations: Adults should aim for at least 150 minutes of moderate-intensity aerobic exercise per week (walking, cycling, swimming) or 75 minutes of vigorous exercise (running, HIIT, competitive sports), as per global health guidelines. Tailored physical activities for older adults with limited mobility, such as yoga or tai chi, can still provide cognitive and physical benefits.

8. Diabetes: Poorly managed diabetes increases the risk of dementia by contributing to vascular damage, inflammation, and insulin resistance, all of which impair brain health. The Commission advocates for comprehensive strategies that integrate diabetes prevention with broader public health initiatives to address other interconnected dementia risk factors like high blood pressure and obesity, emphasising the collective benefits for individuals and healthcare systems worldwide.

Report Recommendations: Adopting healthy lifestyles, including balanced diets and regular physical activity, is critical for diabetes prevention and management. These measures also reduce associated risks like obesity and hypertension, which are interconnected with dementia risk. For individuals with diabetes, controlling blood sugar levels through medication, monitoring, and diet is essential. Proper diabetes management can help prevent complications that affect cognitive health, such as vascular damage.

9. Excessive Alcohol: The report identifies excessive alcohol consumption, defined as more than 21 units per week as a key modifiable risk factor for dementia. Avoiding excessive alcohol use can help reduce the risk of cognitive decline and dementia. Along with addressing other factors like smoking and physical inactivity, this can significantly lower dementia risk. The report also highlights the broader benefits of these measures, including improved quality of life and economic outcomes by delaying dementia onset and reducing its prevalence.

Report Recommendations: Excessive alcohol is part of a broader list of 14 lifestyle and health factors that, when managed effectively, could prevent up to 45% of dementia cases globally. Reducing excessive alcohol intake is considered critical not only for individual health but also for public health strategies targeting dementia prevention, especially in regions with rising prevalence due to aging populations and unhealthy lifestyle patterns.

10. Traumatic Brian Injury (TBI): TBI is a notable risk factor for dementia, as brain injuries can lead to long-term structural and functional damage. The report notes that the risk increases with the severity and frequency of injuries.

Report recommendations: The report highlights promotion of safety measures to reduce TBI risks, such as the use of helmets, seat belts, and fall-prevention strategies. Increased awareness and implementation of policies to protect individuals from sports-related injuries and combat-related brain trauma is recommended as well as improved access to post-injury care to minimise long-term cognitive impacts.

11. Air Pollution: Air pollution is identified as a significant modifiable risk factor for dementia, particularly in older adults. Chronic exposure to polluted air, especially fine particulate matter (PM2.5) and nitrogen dioxide (NO₂), can cause neuroinflammation, oxidative stress, and vascular damage, all of which contribute to cognitive decline.

Report Recommendations: Reducing exposure through advocating for policies to improve air quality and reduce pollution from traffic, industry, and other sources is recommended. For personal protection, consider using air purifiers indoors and limiting outdoor activities during high pollution periods. On a global scale, support initiatives aimed at reducing fossil fuel usage and combat climate change.

12. Social Isolation: Social isolation is identified as a significant risk factor for dementia, particularly in later life. Social isolation can lead to reduced cognitive stimulation, increased stress, depression, and a lack of supportive relationships, all of which contribute to cognitive decline and a higher risk of dementia.

Report recommendations: Staying connected by maintaining regular interactions with family, friends, and community groups and participating in social activities like clubs, classes, or volunteer work to stay mentally and socially active is recommended. Using video calls, social media, or messaging apps to maintain connections, especially for those with mobility challenges is also highlighted. For community support, encouraging initiatives that reduce loneliness, such as neighbourhood programs, senior centres, or intergenerational activities is highlighted.

13. High LDL Cholesterol: This update adds high LDL cholesterol (and vision loss) to the previously established 12 risk factors. Specifically, high LDL cholesterol is estimated to contribute to about 7% of dementia cases, particularly when present in midlife (around age 40). The report emphasises the importance of interventions targeting cholesterol levels.

Report Recommendations: This finding underscores the need for public health strategies focusing on early management of cholesterol levels alongside other preventive measures, such as promoting physical activity and managing cardiovascular health.

14. Vision Loss: Vision impairment, particularly in later life, can lead to reduced social interaction, physical activity, and cognitive stimulation—all of which are critical for maintaining brain health.

Report Recommendations: The report emphasises that addressing vision impairment through regular eye examinations and timely corrective measures, such as prescription glasses or cataract surgery, can help reduce the risk of cognitive decline. Implementing these interventions is particularly important in older adults, as vision loss can lead to social isolation and decreased mental stimulation, both of which are associated with an increased risk of dementia. By prioritising vision health, individuals and healthcare systems can contribute to dementia prevention efforts.

These findings support a life-course approach, advocating for lifestyle changes and policy interventions to mitigate these risks globally, especially in low-income settings where dementia rates are climbing fastest due to aging populations and fewer preventive resources.

Summary of Key Points

Below is the revised list of factors that, if addressed, could prevent or delay almost half of dementia cases over a lifetime:

1. Lower levels of education in early life – limited schooling.

2. Hearing loss – untreated hearing problems.

3. Traumatic brain injury – head injuries.

4. Hypertension – high blood pressure.

5. Alcohol consumption – excessive drinking.

6. Obesity – unhealthy weight.

7. Smoking – tobacco use.

8. Depression – untreated mental health.

9. Social isolation – lack of interaction.

10. Physical inactivity – sedentary lifestyle.

11. Diabetes – poorly managed.

12. Air pollution – exposure to smog.

13. High LDL cholesterol – unhealthy fats.

14. Vision Loss – uncorrected sight problems.

The Lancet Commission’s report emphasises strategies grounded in high-quality research and controlled trials. Although nutrition plays a crucial role in brain health, the direct connection between specific dietary interventions and dementia prevention is still emerging. The complexity of nutrition research such as individual differences, cultural dietary habits, and difficulties in isolating the effects of specific nutrients makes it challenging to establish clear causal links.

Despite this, there is growing interest in diets like the Mediterranean and DASH ( Dietary Approaches to Stop Hypertension) diets, as well as nutrients such as omega-3 fatty acids, choline, and B vitamins, which are thought to support cognitive function. However, a universal consensus on their effectiveness for dementia prevention has yet to be reached.

The report prioritises modifiable risk factors with stronger evidence, like smoking, physical inactivity, hearing loss, and education, which have clearer public health implications. Nutrition may be indirectly addressed within broader lifestyle strategies, such as managing obesity, diabetes, and hypertension, conditions closely tied to dietary habits.

While the report doesn’t delve deeply into specific foods or nutrients, the role of nutrition in supporting brain health and reducing risk factors for dementia should not be overlooked. As research continues to evolve, nutrition remains a critical but underexplored area in dementia prevention. It is essential to focus on the individualised nature of dietary planning, recognising that personalisation is key to unlocking nutrition’s full potential in both preventing and managing cognitive decline.