Dementia Risk: 14 Factors That Could Change Your Odds

Dementia isn't always inevitable. Here's what the evidence says about risk—and what you can do about it.

Dementia is one of the health concerns many people think about as they grow older. The possibility of losing memory, independence and the ability to recognize loved ones can be frightening.

But there's an important message from modern dementia research: age and genetics matter, but they aren't the whole story.

A major 2024 report from the Lancet Commission on dementia prevention, intervention and care identified 14 potentially modifiable risk factors associated with dementia. The researchers estimated that addressing these factors could potentially prevent or delay nearly 45% of dementia cases worldwide.

That figure needs context. It is a population-level estimate based on research about risk factors—not a prediction that an individual can eliminate 45% of their personal risk. Nor does it mean that every case of dementia is preventable.

Still, the findings offer a practical message: there are meaningful steps people can take throughout life to support their long-term brain health.

First, what is dementia?

Dementia is an umbrella term for a decline in memory, reasoning, language or other thinking abilities severe enough to interfere with everyday life.

Alzheimer's disease is the most common cause, but dementia can also result from vascular disease and other neurological conditions. Different causes can overlap, and not every episode of forgetfulness is a sign of dementia.

Occasionally forgetting a name or misplacing keys is not, by itself, evidence of a disease. Persistent changes that interfere with managing money, taking medication, preparing meals or navigating familiar places deserve medical assessment.

The 14 risk factors researchers identified

The Lancet Commission grouped these factors across early life, midlife and later life. Some are medical conditions; others involve behavior or the environment.

Early life

1. Less education

Lower educational attainment earlier in life is associated with a higher risk of dementia later. Education may help build cognitive reserve—the brain's capacity to cope with damage while maintaining function.

This isn't a judgment about intelligence. People with any educational background can develop dementia, and continued learning can be valuable at every age.

Midlife

2. Hearing loss

Hearing loss is associated with increased dementia risk. Difficulty hearing can make communication more demanding and may contribute to social withdrawal. Hearing loss may also share underlying causes with changes in brain health.

A hearing assessment and appropriate treatment are sensible steps if conversations are becoming harder to follow.

3. High LDL cholesterol

The 2024 report added high LDL cholesterol in midlife to its list of risk factors. Elevated LDL contributes to cardiovascular disease, and research has linked higher midlife LDL levels with increased dementia risk.

Vascular health and brain health are closely connected. Discuss cholesterol management with a healthcare professional rather than relying on supplements or making medication changes independently.

4. Depression

Depression is associated with higher dementia risk, although the relationship is complex. Depression can sometimes precede dementia, occur alongside it, or share other contributing factors.

Depression is treatable, and persistent symptoms deserve attention regardless of whether they affect future dementia risk.

5. Traumatic brain injury

Head injuries are associated with increased dementia risk. Prevention matters: use appropriate helmets, wear seat belts, reduce fall hazards and seek medical assessment after significant head trauma.

6. Physical inactivity

Regular physical activity supports cardiovascular health, mobility and general well-being. Inactivity is associated with greater dementia risk, although studies do not establish that exercise alone will prevent dementia.

Choose activities suited to your ability and build consistency rather than chasing extreme workouts.

7. Diabetes

Diabetes is associated with increased dementia risk, particularly when blood sugar and related vascular risk factors are poorly controlled.

Regular screening when appropriate and effective management of diabetes can reduce other serious health risks and may also support brain health.

8. Smoking

Smoking damages blood vessels and increases the risk of stroke and cardiovascular disease. It is also associated with dementia risk.

Stopping smoking can improve health even after many years of use. Support from a healthcare professional can make quitting more achievable.

9. High blood pressure

High blood pressure can damage blood vessels and increase the risk of stroke, both of which can affect the brain. The timing matters: high blood pressure during midlife is an established dementia risk factor.

Have your blood pressure checked and work with a healthcare professional to manage it. The right target can depend on age, other conditions and individual circumstances.

10. Obesity

Obesity during midlife is associated with increased dementia risk. Possible pathways include diabetes, high blood pressure, inflammation and vascular disease.

This does not mean that weight alone determines brain health. In later life, unintentional weight loss can itself be a warning sign of illness and should not automatically be treated as beneficial.

11. Excessive alcohol consumption

Heavy alcohol consumption can damage the brain directly and indirectly, including through nutritional deficiencies, liver disease and injuries.

Avoiding heavy drinking is a practical step toward protecting overall health. People who drink heavily or daily may need medical advice before stopping abruptly because withdrawal can be dangerous.

Later life

12. Social isolation

People who have little social contact have a higher risk of dementia in observational research. Isolation can also affect mood, activity levels and general health.

Regular contact with friends, family, neighbors or community groups can help. Social connection does not have to mean a busy social calendar; meaningful contact matters.

13. Air pollution

Long-term exposure to air pollution is associated with increased dementia risk. Individuals cannot control every environmental exposure, but following local air-quality advice during severe pollution events can help reduce exposure.

14. Untreated vision loss

The 2024 report identified untreated vision loss as another potentially modifiable risk factor. Vision difficulties may make daily activities and social participation harder.

Regular eye examinations and appropriate treatment or corrective lenses can help maintain independence and quality of life.

A practical tool: The Brain Care Score

Knowing the risk factors is one thing. Knowing where to start is another.

Dr. Jonathan Rosand, a neurologist and co-founder of the Global Brain Care Coalition, helped develop the Brain Care Score, an assessment designed to help people identify opportunities to protect brain health and lower their risk of dementia, stroke and depression.

The score considers 12 factors spanning physical health, lifestyle and social well-being. These include blood pressure, blood sugar, cholesterol, body mass index, diet, exercise, sleep, smoking, alcohol, stress management, relationships and purpose.

The idea is straightforward: rather than focusing on a single supplement or brain-training app, look at the collection of habits and health conditions that influence brain health over time.

Managing high blood pressure, addressing unhealthy cholesterol levels, staying physically active, eating a balanced diet and maintaining social connections can all contribute to better overall health. Some of these factors are associated with dementia risk, and improving them may help reduce risk.

An important distinction: The Brain Care Score and the Lancet Commission's 14 risk factors are related but different frameworks. The score is a 12-item, 21-point tool; it does not simply measure all 14 Lancet risk factors.

The Brain Care Score is a risk-reduction tool, not a diagnostic test or a guarantee against dementia. A score cannot tell someone whether they will develop dementia, and improving a score does not establish exactly how much an individual's risk has changed.

For readers who want a structured starting point, the Global Brain Care Coalition provides information about the score and other brain-health resources.

You don't have to change everything at once. Identify one or two areas that need attention and make sustainable improvements.

What does the “45%” figure really mean?

The Lancet Commission estimated that nearly 45% of dementia cases worldwide could potentially be prevented or delayed if the 14 risk factors were addressed.

That is an important finding, but it is easy to misunderstand.

The estimate combines population-level data about how common these risk factors are and how strongly they are associated with dementia. The factors overlap, and the calculation relies on assumptions about how much risk might change if exposures were reduced.

It does not mean that:

• Every person can reduce their individual dementia risk by 45%.
• Every listed factor has been proven to cause dementia in every circumstance.
• Eliminating these factors would prevent all dementia.
• Someone who follows every recommendation is guaranteed to remain cognitively healthy.

Some people develop dementia despite healthy habits. Others live with several risk factors and never develop it. The goal is to improve the odds, not to promise certainty.

What about age and genetics?

Age remains one of the strongest risk factors for dementia. The likelihood of developing most forms of dementia increases as people get older.

Family history also matters. Having a close relative with Alzheimer's disease can increase risk, and certain genetic variants—particularly APOE ε4—can increase susceptibility.

But increased susceptibility is not destiny. Genetics, health conditions, environment and other influences interact in complicated ways.

Nor should anyone assume that memory problems are simply a normal part of aging. Persistent or worsening cognitive changes deserve attention.

Six practical priorities for brain health

The research doesn't offer a magic pill. It points toward a collection of sensible, achievable actions.

1. Manage cardiovascular risk. Keep up with blood pressure, cholesterol and diabetes care.

2. Stay physically active. Choose regular aerobic activity, strength training and balance work appropriate to your abilities.

3. Address hearing and vision problems. Don't simply accept declining hearing or eyesight as unavoidable.

4. Avoid smoking and heavy alcohol use. Seek support when changing established habits is difficult.

5. Maintain social connections and treat depression. Emotional health and meaningful contact are part of overall health.

6. Protect your brain. Reduce the risk of head injuries, and seek medical advice for significant injuries or persistent changes in memory and thinking.

These steps can improve health in their own right, even though their precise effect on an individual's dementia risk cannot be predicted.

Can supplements or brain-training apps prevent dementia?

Be skeptical of products promising to prevent, reverse or cure dementia.

No supplement has been established as a universal dementia-prevention treatment. Correcting a genuine nutritional deficiency can be important, but taking extra vitamins without a demonstrated need is not the same as preventing dementia.

Brain games and mentally stimulating activities can be enjoyable and may help maintain particular skills. However, improvement on a game does not prove that the activity prevents dementia.

A healthy lifestyle is worthwhile, but it should not be sold as a guaranteed shield against disease.

When should you seek an assessment?

Consider a medical appointment if memory or thinking changes persist, worsen, or interfere with everyday tasks. A healthcare professional can assess symptoms and look for potentially treatable contributors, such as medication effects, depression, sleep problems or certain vitamin and thyroid disorders.

Sudden confusion or abrupt changes in speech, strength or awareness are different: they may indicate an emergency, including a stroke, and require immediate medical attention.