Dementia cannot always be prevented, but addressing several health, lifestyle and environmental risks may reduce or delay some cases.

Dementia is often viewed as an unavoidable consequence of growing older. However, dementia is not a normal part of ageing, and growing evidence shows that some cases may be prevented or delayed.

In July 2026, the World Health Organization released updated global guidelines on reducing the risk of cognitive decline and dementia.

According to WHO, addressing a combination of modifiable risk factors across a person’s lifetime could prevent or delay up to 45 per cent of dementia risk at the population level.

These factors include smoking, physical inactivity, high blood pressure, diabetes, obesity, harmful alcohol use, hearing loss, social isolation and exposure to air pollution.

This does not mean dementia is always preventable. Age, genetics and some medical conditions cannot be changed. It also does not mean that a person who develops dementia failed to live healthily.

What the new guidance shows is that protecting brain health should begin long before old age and should involve individuals, healthcare systems, workplaces, communities and governments.

What Is Dementia?

Dementia is a general term for a group of symptoms caused by diseases that damage the brain.

It can affect:

Memory
Thinking
Language
Judgement
Problem-solving
Behaviour
Personality
The ability to perform everyday activities

Dementia is not a single disease.

Alzheimer’s disease is its most common cause, but other causes include vascular dementia, dementia with Lewy bodies, frontotemporal dementia and mixed dementia.

A person may have more than one type of brain disease at the same time.

Dementia is usually diagnosed when changes in memory or thinking become serious enough to interfere with independent daily life. Occasional forgetfulness, such as temporarily misplacing keys or forgetting a name, does not automatically mean a person has dementia.

Is Dementia a Normal Part of Ageing?

No.

Ageing increases the likelihood of dementia, but dementia is not an inevitable or normal stage of growing older.

Many older adults continue to think clearly, learn new information, manage their responsibilities and live independently.

Normal ageing may involve taking slightly longer to remember a name or learn a new task. Dementia causes more persistent and progressive changes that interfere with everyday functioning.

Examples may include:

Repeatedly forgetting recent conversations
Becoming lost in familiar places
Difficulty managing money or medicines
Struggling to follow familiar instructions
Losing the ability to complete routine activities
Major changes in judgement, behaviour or personality

These signs require assessment rather than being dismissed as “just old age.”

Can Dementia Really Be Prevented?

Some dementia cases may be prevented or delayed, but there is currently no guaranteed method for preventing every case.

WHO’s 2026 guidance states that up to 45 per cent of dementia risk could potentially be prevented or delayed by addressing modifiable factors.

The estimate is based on the combined contribution of several risks across populations. It should not be interpreted as a promise that changing one habit will reduce an individual’s risk by 45 per cent.

The practical message is that brain health is influenced by many of the same factors that affect the heart and blood vessels.

Actions that protect cardiovascular health may also help protect the brain.

What Is New in the WHO Guidance?

WHO’s updated guidelines build on its earlier 2019 recommendations and provide new evidence on lifestyle, medical and environmental interventions.

Important areas include:

Physical activity
Tobacco cessation
Blood-pressure control
Diabetes management
Healthy diet
Weight management
Hearing care
Cognitive and social activity
Reduction of harmful alcohol use
Reduction of air-pollution exposure
Appropriate management of depression
Avoiding unproven supplements

The updated guidance places greater emphasis on reducing exposure to air pollution and addressing hearing impairment.

It also advises against routinely taking vitamin or omega-3 supplements solely to prevent dementia when a person does not have a diagnosed deficiency.

Dementia Risk Factors That Cannot Be Changed

Some important risk factors cannot be modified.

These include:

Increasing age

Dementia becomes more common with increasing age, particularly after 65.

However, age alone does not cause dementia, and some people develop dementia at a younger age.

Genetics and family history

Certain genes can increase a person’s risk.

Having a parent or sibling with dementia does not mean that a person will definitely develop it. Most dementia cases result from a complex interaction of age, genes, health, lifestyle and environmental factors.

Some neurological and genetic conditions

Certain conditions can directly increase dementia risk and cannot be prevented through lifestyle changes alone.

Because these factors cannot be changed, prevention efforts focus mainly on risks that individuals, healthcare systems and communities can influence.

1. Stay Physically Active

Regular physical activity supports blood circulation, heart health, blood-pressure control, weight management and glucose regulation.

These benefits also support brain health.

Adults should aim to combine:

Aerobic activity such as brisk walking, cycling, dancing or swimming
Strength exercises
Balance exercises, especially for older adults
Reduced periods of prolonged sitting

People do not need to begin with intense exercise.

A person who has been inactive can start with short walks and gradually increase duration and intensity.

The best activity is one that is safe, affordable and likely to be continued.

People with heart conditions, serious mobility limitations or other medical concerns should seek professional advice before beginning a demanding exercise programme.

2. Stop Smoking

Smoking damages blood vessels and increases the risk of stroke, heart disease and several cancers.

It is also associated with a higher risk of cognitive decline and dementia.

Stopping smoking can improve health at any age. The earlier a person stops, the greater the potential benefit, but quitting later in life can still be valuable.

Smoking cessation may require more than willpower.

Useful support can include:

Behavioural counselling
Support groups
Healthcare follow-up
Approved cessation treatment
Support from family members
Avoiding environments that trigger smoking

Reducing exposure to second-hand smoke is also important.

3. Control High Blood Pressure

High blood pressure can damage arteries throughout the body, including those supplying the brain.

Over time, this can increase the risk of stroke, vascular brain injury and cognitive decline.

High blood pressure may produce no obvious symptoms. Regular checks are therefore essential.

Blood-pressure control may involve:

Reducing excess salt
Eating a balanced diet
Exercising regularly
Maintaining a healthy weight
Taking prescribed medication consistently
Avoiding tobacco
Limiting harmful alcohol consumption
Attending follow-up appointments

People should not stop blood-pressure medicines because they feel well. Hypertension often remains silent while continuing to damage the heart, kidneys and brain.

AnjKreb’s guide to protein in urine and its possible causes explains how hypertension and diabetes can also affect kidney health. These conditions often need long-term monitoring rather than treatment only when symptoms appear.

4. Prevent and Manage Diabetes

Diabetes is associated with damage to blood vessels and may contribute to cognitive decline.

People with diabetes should work with their healthcare providers to manage:

Blood glucose
Blood pressure
Cholesterol
Body weight
Kidney health
Physical activity
Diet
Prescribed medication

Preventing or delaying type 2 diabetes through healthy eating, regular activity and weight management may also support long-term brain health.

However, dementia prevention should not become another source of blame for people living with diabetes.

Access to affordable medicines, healthy food, safe places for exercise and regular healthcare strongly influences a person’s ability to control the condition.

5. Manage Cholesterol and Cardiovascular Risk

Elevated cholesterol, particularly during midlife, may contribute to the development of vascular disease and dementia.

People should consider having their cholesterol and overall cardiovascular risk assessed, especially when they have:

High blood pressure
Diabetes
Obesity
A family history of cardiovascular disease
A history of smoking
Previous stroke or heart disease

Treatment may involve dietary changes, physical activity, weight management and cholesterol-lowering medication when clinically indicated.

Medication should be based on a qualified clinician’s assessment rather than self-treatment.

6. Eat a Balanced, Heart-Healthy Diet

No single food can prevent dementia.

A dietary pattern that supports heart and blood-vessel health may also support brain health.

A practical diet should emphasise:

Vegetables
Fruits
Beans and other legumes
Whole grains
Nuts and seeds
Fish where available and affordable
Healthy sources of protein
Appropriate portions
Limited highly processed foods
Limited excessive salt
Limited added sugar
Limited trans fats and excessive saturated fat

For Nigerians, this does not require abandoning local foods.

Healthy choices can include beans, vegetables, fruits, fish, groundnuts, whole or less-refined grains and meals prepared with moderate salt and oil.

Dietary advice should also recognise affordability and availability. Telling people to eat expensive imported foods is neither realistic nor necessary.

7. Maintain a Healthy Weight

Obesity, particularly during midlife, is associated with diabetes, hypertension, cardiovascular disease and increased dementia risk.

Weight management should focus on sustainable health rather than unrealistic body ideals.

Helpful actions include:

Regular physical activity
Balanced meals
Appropriate portion sizes
Reducing sugar-sweetened drinks
Limiting frequent consumption of heavily processed foods
Adequate sleep
Medical assessment where weight changes are unexplained

Extreme diets and unregulated weight-loss products are not necessary for protecting brain health and may cause harm.

8. Protect Hearing

Hearing loss is increasingly recognised as an important modifiable dementia risk factor.

A person who cannot hear clearly may withdraw from conversations and social activities. The brain may also use additional effort to interpret sounds, potentially affecting other cognitive functions.

People should seek hearing assessment when they:

Frequently ask others to repeat themselves
Increase television or radio volume excessively
Struggle to follow conversations in groups
Experience persistent ringing in the ears
Have difficulty hearing telephone conversations
Withdraw socially because communication has become difficult

Hearing aids and other appropriate interventions may improve communication and quality of life.

Protecting hearing also involves reducing exposure to very loud sound and using suitable ear protection in noisy workplaces.

9. Remain Socially Connected

Social isolation is associated with poorer physical and mental health and may contribute to dementia risk.

Social connection does not require attending large events.

It may include:

Regular conversations with relatives
Faith-community participation
Community associations
Volunteering
Visiting friends
Group exercise
Learning activities
Phone or video calls
Supporting grandchildren or younger people
Participating in cultural or professional groups

The quality of social connection matters more than the size of a person’s social circle.

People who are lonely, bereaved or physically limited may need active assistance to remain connected.

10. Keep the Brain Mentally Active

Mental activity may support cognitive reserve, which refers to the brain’s ability to cope with age-related or disease-related changes.

Useful activities may include:

Reading
Writing
Learning a language
Playing strategy games
Learning to use technology
Studying a new subject
Playing music
Teaching others
Completing puzzles
Participating in discussions
Learning a new practical skill

There is no evidence that one particular puzzle, application or “brain game” can guarantee dementia prevention.

The strongest approach combines mental activity with physical exercise, social interaction and management of medical risks.

11. Treat Depression and Protect Mental Health

Depression and dementia can sometimes produce overlapping symptoms, including poor concentration, reduced motivation, sleep disturbance and memory complaints.

Depression may also be associated with increased dementia risk.

Persistent sadness, loss of interest, social withdrawal, sleep changes or difficulty functioning should be assessed and treated.

Not every memory complaint in an older adult is dementia. Depression, grief, anxiety, medication effects and sleep problems may also affect memory and concentration.

Treating these conditions may improve both quality of life and cognitive functioning.

12. Avoid Harmful Alcohol Use

Heavy or prolonged alcohol consumption can damage the brain and increase the risk of several medical conditions associated with cognitive decline.

People should avoid binge drinking and harmful patterns of alcohol use.

A person who has developed dependence should seek professional support rather than stopping suddenly without medical guidance, because withdrawal can sometimes be dangerous.

Alcohol should not be promoted as a method of protecting the heart or preventing dementia.

13. Reduce the Risk of Head Injury

Head injuries may increase the risk of cognitive problems and dementia later in life.

Prevention measures include:

Wearing seat belts
Using appropriate helmets during relevant activities
Preventing falls at home
Improving lighting
Removing loose rugs and obstacles
Reviewing medicines that cause dizziness
Checking vision
Using mobility support when necessary
Following workplace-safety standards

Older adults who fall repeatedly should receive assessment rather than having the falls dismissed as clumsiness.

14. Reduce Exposure to Air Pollution

The new WHO guidance gives greater attention to air pollution as a dementia risk factor.

Exposure may come from:

Vehicle exhaust
Industrial emissions
Waste burning
Diesel generators
Tobacco smoke
Kerosene or solid-fuel cooking
Poorly ventilated indoor cooking
Dust and fine particulate pollution

Individuals cannot solve air pollution alone.

Governments and communities need policies that improve transport, energy, waste management, housing, industrial regulation and air-quality monitoring.

At household level, helpful measures may include:

Avoiding indoor waste burning
Improving ventilation during cooking
Using cleaner cooking methods where accessible
Avoiding exercise beside heavily congested roads
Keeping indoor environments smoke-free
Following reliable local air-quality information where available

WHO’s inclusion of air pollution shows that dementia prevention is not only about individual lifestyle choices. Environmental and public-policy decisions also shape brain health.

Should You Take Supplements to Prevent Dementia?

WHO does not recommend routinely taking vitamins, multivitamins, omega-3 products or similar supplements solely to prevent dementia in people without a diagnosed deficiency.

Supplements are often marketed using claims about memory and brain performance, but “natural” does not automatically mean effective or safe.

Some supplements can:

Interact with medicines
Cause side effects
Provide excessive doses
Delay proper medical assessment
Waste money
Create false reassurance

A doctor may recommend a specific supplement when tests or clinical assessment show a deficiency.

For example, vitamin B12 deficiency can cause neurological and cognitive symptoms and should be treated appropriately. This is different from taking supplements without evidence of deficiency.

Common Dementia Myths

Myth 1: Dementia is a normal part of ageing

Dementia becomes more common with age, but it is not a normal or inevitable part of ageing.

Myth 2: Every episode of forgetfulness is dementia

Stress, poor sleep, depression, medicines, infection, thyroid disease and vitamin deficiencies can affect memory.

Persistent or worsening changes should be assessed, but occasional forgetfulness alone does not establish dementia.

Myth 3: Dementia can always be prevented through healthy living

Healthy living can reduce risk, but it cannot guarantee prevention.

People can develop dementia despite making healthy choices, and they should never be blamed for their condition.

Myth 4: Only very old people develop dementia

Dementia is more common in older people, but younger-onset dementia can occur before age 65.

Myth 5: Memory supplements can prevent Alzheimer’s disease

There is insufficient evidence to recommend routine supplements for dementia prevention in people without a diagnosed deficiency.

Myth 6: Nothing can be done after dementia begins

Although there is no widely available cure for most dementia, early diagnosis can help people access treatment, plan care, manage symptoms, address safety risks and receive family support.

When Should Someone Seek a Memory Assessment?

Seek medical assessment when memory or thinking changes are persistent, worsening or interfering with everyday life.

Warning signs include:

Repeatedly asking the same questions
Forgetting recent important events
Becoming lost in familiar places
Difficulty managing money
Missing medicines or taking them incorrectly
Struggling with familiar tasks
Difficulty finding common words
Poor judgement
Noticeable personality or behaviour changes
Withdrawal from work or social activities
Difficulty following conversations
Increasing dependence on others

A sudden change in memory, awareness or behaviour requires urgent medical attention.

Sudden confusion may be caused by infection, stroke, low blood sugar, medication effects, dehydration or another acute condition. It should not automatically be labelled dementia.

What Happens During a Dementia Assessment?

A proper assessment may include:

Discussion of symptoms
Information from a close relative or caregiver
Review of medicines
Memory and thinking tests
Physical and neurological examination
Blood tests
Assessment for depression
Hearing and vision checks
Brain imaging where indicated
Evaluation of the person’s daily functioning

Some causes of cognitive symptoms may be treatable or partly reversible.

These include:

Medication side effects
Vitamin B12 deficiency
Thyroid disorders
Depression
Sleep disorders
Some infections
Poor hearing or vision
Uncontrolled diabetes
Severe anaemia

Early assessment therefore matters even when symptoms are mild.

Dementia Prevention Is a Life-Course Issue

Brain health is shaped throughout life.

Education in childhood, cardiovascular health in midlife and social, physical and cognitive activity in later life can all influence dementia risk.

This means prevention should not begin only when a person reaches retirement age.

Schools, workplaces, healthcare systems and communities can contribute by promoting:

Education
Clean air
Tobacco control
Safe physical activity
Healthy food access
Blood-pressure screening
Diabetes care
Hearing services
Mental-health care
Social inclusion
Safe housing for older adults

Technology may also support screening, appointment reminders, remote consultations and chronic-disease monitoring.

However, as discussed in AI in African Healthcare: What It Can Improve and What Could Go Wrong, digital tools should support qualified health professionals rather than replace proper clinical assessment.

Publishing note: Replace the placeholder above with the live AI in African Healthcare URL once that article is published.

Frequently Asked Questions

Can dementia be completely prevented?

Not always.

Some cases may be prevented or delayed by addressing modifiable risks, but age, genetics and other factors cannot be eliminated.

What is the most important way to prevent dementia?

There is no single most important action for everyone.

The strongest approach combines regular physical activity, tobacco avoidance, healthy eating, social and mental activity and effective management of blood pressure, diabetes, cholesterol, hearing loss and other medical risks.

Does exercise prevent Alzheimer’s disease?

Exercise cannot guarantee that a person will not develop Alzheimer’s disease.

However, regular physical activity supports cardiovascular and metabolic health and is recommended as part of dementia-risk reduction.

Can high blood pressure cause dementia?

Long-term uncontrolled hypertension can damage blood vessels and increase the likelihood of stroke, vascular cognitive impairment and dementia.

Does diabetes increase dementia risk?

Diabetes is associated with a higher risk of cognitive decline and dementia, particularly when blood glucose and cardiovascular risks remain poorly controlled.

Can hearing aids reduce dementia risk?

Treating hearing loss may help preserve communication, social engagement and daily functioning. WHO’s updated guidance supports addressing hearing impairment as part of dementia-risk reduction.

Can vitamins prevent memory loss?

Routine vitamin supplementation is not recommended solely to prevent dementia unless a deficiency or another medical indication has been identified.

At what age should dementia prevention begin?

Brain-health protection should begin early and continue throughout life.

Midlife control of blood pressure, cholesterol, diabetes, smoking and obesity may be particularly important.

Is dementia the same as Alzheimer’s disease?

No.

Dementia is a general term describing cognitive symptoms that interfere with daily life. Alzheimer’s disease is the most common disease that causes dementia.

The Bottom Line

Dementia cannot always be prevented, but it should no longer be viewed as completely unavoidable.

The new WHO guidance shows that a substantial proportion of dementia risk may be prevented or delayed by addressing health, lifestyle, social and environmental factors.

Practical priorities include:

Staying physically active
Avoiding tobacco
Managing blood pressure
Preventing or controlling diabetes
Managing cholesterol
Eating a balanced diet
Protecting hearing
Remaining socially and mentally active
Treating depression
Avoiding harmful alcohol use
Preventing head injuries
Reducing exposure to air pollution
Avoiding unproven memory supplements

These measures support overall health even when dementia cannot be prevented.

The goal is not to promise that every case can be avoided. It is to give individuals, families, health systems and governments practical opportunities to protect brain health and support healthier ageing.

Medical Disclaimer

This article is for general health education and does not replace medical diagnosis, assessment or treatment.

Anyone experiencing persistent memory loss, confusion, behavioural change or difficulty performing normal activities should consult a qualified healthcare professional.

Sudden confusion, weakness, speech difficulty, severe headache or loss of consciousness requires urgent medical attention.

Author Bio

Adeyinka Joseph Alonge is a public health professional, researcher and writer with interests spanning health, science, technology, personal development and practical knowledge for everyday life.