Dementia affects millions of people around the world, gradually impairing memory, reasoning, communication and the ability to manage everyday life. It is not a single disease. Instead, dementia is an umbrella term for several conditions that damage the brain.
The World Health Organization (WHO) estimated that as of 2021, 57 million people worldwide were living with dementia. Alzheimer’s disease is the most common cause, accounting for an estimated 60% to 70% of cases.
Age remains the strongest known risk factor. Genetics also matter, particularly for some forms of Alzheimer’s disease. Still, growing research suggests that dementia is not simply an unavoidable part of ageing. Many influences on brain health can be addressed through medical care, healthier routines, social support and public policies that make healthy choices easier.
A major report from The Lancet Commission on dementia prevention, intervention and care identified 14 potentially modifiable risk factors linked with dementia risk across the lifespan.
The Commission estimated that, at a population level, addressing these factors could potentially prevent or delay a substantial proportion of dementia cases.
That does not mean any individual can guarantee they will avoid dementia. Nor does it mean people are personally responsible for every risk they face. Education, access to health care, safe housing, clean air, affordable food, opportunities for exercise and access to hearing or vision care all shape health.
Yet the findings offer a hopeful message: small, sustained improvements in several areas may support brain health over time.
A study published on 30 June 2026 in The Lancet Healthy Longevity also drew attention to a practical challenge. Public awareness campaigns may help people recognise dementia risk factors, but knowledge alone does not reliably lead to lasting change.
The study suggested that interactive approaches, particularly those led by trusted members of local communities, may be more effective at helping people put health advice into practice.
That could mean community walking groups, local blood-pressure checks, support to stop smoking, accessible hearing services, exercise classes, social clubs, health education, health media and journalism delivered by people who understand the needs of the area.
Prevention is rarely a matter of willpower alone. It often depends on whether support is available when people need it.
The first of the 14 factors begins early in life: lower levels of education.
Education is thought to help build “cognitive reserve”, meaning the brain may become better able to cope with age-related changes or disease-related damage before symptoms become noticeable. This does not suggest that people with less formal education are destined to develop dementia. It highlights the importance of educational opportunity, literacy, curiosity and lifelong learning.
Learning does not have to mean returning to a classroom. Reading, acquiring a new skill, joining a discussion group, learning a language, playing music, volunteering or taking up a mentally demanding hobby may all provide cognitive stimulation. The evidence does not support one perfect “brain-training” activity. What matters is staying engaged in meaningful ways.
Hearing loss in midlife is another important factor. Untreated hearing difficulties can make conversations tiring, reduce social contact and place extra strain on the brain as it works to interpret sound. People who struggle to follow speech may begin to withdraw from family events, workplaces or social gatherings. Over time, isolation and reduced stimulation may contribute to poorer cognitive health.
Hearing loss should not be dismissed as an inconvenience or an inevitable feature of getting older. Hearing assessments, treatment for ear conditions and properly fitted hearing aids can improve communication and quality of life. Research is increasingly exploring whether treating hearing loss may also reduce cognitive decline, although the size of that benefit is still being studied.
High levels of low-density lipoprotein, or LDL, cholesterol are also associated with dementia risk. LDL cholesterol can contribute to narrowing and damage in blood vessels, affecting blood flow to the heart and brain. Vascular damage raises the risk of stroke and vascular dementia. It may also contribute to processes involved in Alzheimer’s disease.
Cholesterol management should be individualised. Diet, physical activity and medicines such as statins may be recommended depending on a person’s overall cardiovascular risk. People should not stop or alter prescribed medication because of online advice. A GP or other qualified clinician can help determine the safest plan.
Depression is included among the risk factors, though the relationship is complex. Depression may affect sleep, stress levels, physical activity, social participation and the ability to manage other health conditions. It is also possible that depression in later life can sometimes occur alongside early changes in the brain. One does not necessarily cause the other.
What is clear is that depression deserves timely care. Persistent low mood, loss of interest, hopelessness, major changes in appetite or sleep, and thoughts of self-harm should be taken seriously. Effective support can include talking therapies, social support, lifestyle measures and medication when appropriate. Seeking help is a form of health care, not a personal failure.
Traumatic brain injury is another modifiable risk factor. Serious head injuries, repeated blows to the head and some sports-related impacts have been linked with a higher later risk of cognitive problems. The risk varies according to the type, severity and number of injuries. Not every concussion leads to dementia, but prevention remains important.
Helmets, seatbelts, fall-prevention measures, safer workplaces and appropriate sports rules can all reduce the likelihood of head injury. Older adults should also discuss falls with a health professional, particularly if they have dizziness, poor balance, medication side effects or vision problems.
High blood pressure is one of the clearest threats to brain health. Hypertension can damage small blood vessels in the brain over many years, increasing the risk of stroke, vascular injury and cognitive decline. It often has no obvious symptoms. Regular blood-pressure checks are therefore essential, especially from midlife onwards.
The good news is that high blood pressure can often be managed. Treatment may include reducing salt intake, being more physically active, improving sleep, losing weight where appropriate, limiting alcohol and taking prescribed medication. The aim is not perfection. It is consistent control over time.
Physical inactivity is closely linked with several other dementia risk factors, including high blood pressure, diabetes, obesity and depression. Regular movement benefits the heart, circulation, mood, sleep, balance and independence. These benefits are likely to support brain health as well.
A brisk walk, gardening, cycling, swimming, dancing or chair-based exercise can all count. The best activity is often the one a person can enjoy and continue. Those with long-term conditions, mobility limitations or concerns about starting exercise should seek personalised advice from a clinician or qualified exercise professional.
Diabetes is another major concern because persistently elevated blood glucose can harm blood vessels and nerves throughout the body. It is associated with a higher risk of cardiovascular disease and cognitive decline. Good diabetes care includes monitoring, medication where prescribed, food choices that support stable blood sugar, physical activity and regular reviews.
Smoking compounds risk through vascular damage, inflammation and oxidative stress. It harms blood vessels throughout the body and increases the likelihood of stroke, heart disease and several cancers. Stopping smoking can be difficult, yet support works. Nicotine replacement, stop-smoking medicines, counselling and local services can all improve the chances of quitting successfully.
Obesity is also associated with dementia risk, particularly through its relationship with diabetes, high blood pressure, sleep problems and cardiovascular disease. Weight should be discussed sensitively. Health is not determined by one number on a scale, and rapid or extreme dieting is not a sensible route to brain health. Sustainable eating patterns, regular activity, adequate sleep and clinical support where needed are more useful goals.
Heavy alcohol consumption can damage the brain directly and indirectly. It can disrupt sleep, affect nutrition, raise blood pressure, increase the risk of falls and worsen mental health. People who drink should follow national low-risk drinking guidance. Those who do not drink should not start drinking in the belief that alcohol protects the brain.
Social isolation in later life is also linked with a higher risk of cognitive decline. Human connection matters. Conversations, shared activities, friendships, volunteering, faith groups, hobbies and family contact can all provide emotional support and mental stimulation. For some people, loneliness is not easily solved by simply being told to socialise. Bereavement, disability, poverty, caring duties and transport barriers can make connection harder.
Untreated vision loss may create similar barriers. Difficulty seeing can reduce confidence, limit independence and make it harder to take part in social or mentally stimulating activities. Regular eye tests and timely treatment for conditions such as cataracts can protect quality of life. Sudden changes in vision require urgent medical attention.
Air pollution is the final factor identified by the Commission. Scientists are investigating how fine particles in polluted air may contribute to inflammation, vascular problems and brain changes linked with dementia. Individuals can reduce exposure on high-pollution days where practical, though this is fundamentally a public-health issue requiring cleaner transport, stronger environmental standards and better urban planning.
These 14 factors often overlap. Hearing loss can lead to withdrawal from social life. Physical inactivity can increase the likelihood of obesity, diabetes and hypertension. Depression may make it harder to attend appointments, exercise or maintain relationships. A person does not need to fix everything at once.
The most realistic approach is to begin with one or two manageable changes. Book a hearing or eye test. Check blood pressure. Take a regular walk with a neighbour. Ask for help with low mood. Stop smoking with professional support. Review diabetes or cholesterol treatment with a clinician. Each step can support several parts of health at the same time.
Dementia prevention is not a promise. It is a long-term effort to reduce risk, preserve independence and support healthier ageing. People with new or worsening memory problems, confusion, personality changes, difficulty managing money or daily tasks, or sudden changes in thinking should seek medical assessment rather than assuming the symptoms are normal ageing.
Brain health is built across a lifetime. The evidence increasingly suggests that it is shaped not only by what happens inside the brain, but by the quality of education, medical care, relationships, communities and environments surrounding it.
The post Nearly 50% of All Dementia Cases Could Be Prevented by Addressing These 14 Risk Factors first appeared on PP Health Malaysia.
