Almost Half of Dementia Cases Could Be Prevented: 14 Factors That Can Increase Your Risk

• Millions of people around the world are living with cognitive impairment associated with dementia.
• However, nearly half of dementia cases could potentially be prevented by addressing 14 risk factors.
• Experts say it’s important to address all these factors, as they work together to influence risk.

The World Health Organization (WHO) explains that as of 2021, 57 million people worldwide were living with dementia.

This condition, which impairs memory, thinking, and daily functioning, can be caused by various diseases that damage the brain. Alzheimer’s disease is the most common form of dementia, accounting for 60%-70% of cases.

According to a 2024 report from The Lancet Commissions, almost half (45%) of dementia cases could potentially be prevented.

The document also identifies 14 modifiable risk factors that can contribute to dementia prevention, including various behaviors, medical conditions, and social and environmental factors.

Knowing these risk factors is an important step. However, a new study published on June 30, 2026, in The Lancet Healthy Longevity, suggests that there is a gap between people knowing how to prevent dementia and actually putting those principles into practice.

The authors note that while awareness campaigns can reach a large number of people, these efforts don’t tend to be particularly effective in motivating them. Interactive approaches led by trusted community members appear to be the most effective way to elicit change.

Knowing your dementia risk factors is the first step in changing them

To help highlight the biggest modifiable risk factors, Healthline spoke with Laura Bojarskaite, PhD, a neuroscientist and sleep researcher at the University of Oslo.

Bojarskaite, who was not involved in the report or the study, told Healthline that the research highlights “an important but often misunderstood message.”

Nearly half of dementia cases may be due to 14 risk factors, which people can often address with lifestyle changes. They include:

Early-life low education

“Education likely builds cognitive reserve, giving the brain greater resilience against age-related pathology,” she said. “Lifelong learning and cognitively stimulating activities may help maintain this reserve.”

Midlife hearing loss

Bojarskaite said that hearing loss can increase cognitive load, reduce social engagement, and accelerate brain atrophy.

“Early hearing assessment and appropriate hearing aids are important interventions,” she said.

High LDL cholesterol

“Elevated LDL contributes to vascular disease and may impair blood flow to the brain, increasing the risk of both vascular dementia and Alzheimer’s disease,” she said. Diet, exercise, and medication as needed are important interventions.

Depression

Pointing to the association between chronic stress, inflammation, sleep disruption, and changes in the brain’s hippocampus, Bojarskaite said early recognition and treatment are essential when it comes to depression.

Traumatic brain injury

“Head injuries can trigger long-lasting neuroinflammation and increase the accumulation of pathological proteins linked to neurodegeneration,” she explained. Preventive measures include steps such as sports safety and fall prevention.

Hypertension

“High blood pressure damages blood vessels throughout the body, including the brain, impairing blood flow and increasing the risk of vascular injury and dementia,” said Bojarskaite.

The Alzheimer’s Society states that maintaining a healthy weight, exercising, limiting salt intake, reducing caffeine intake, limiting alcohol, and quitting smoking can all help manage blood pressure.

There are also effective medications available.

Physical inactivity

“Exercise is one of the most powerful brain-health interventions we know,” Bojarskaite said. “Physical activity improves cardiovascular health, promotes neuroplasticity, and supports the growth and survival of neurons.”

Diabetes

“Chronically elevated blood glucose damages blood vessels and may impair insulin signaling in the brain, processes that have been linked to cognitive decline and dementia risk,” she said.

The International Diabetes Federation notes the importance of managing your blood sugar if you have diabetes. They further state that certain diabetes medications may reduce dementia risk.

Smoking

“Smoking increases oxidative stress, inflammation, and vascular damage, all of which negatively affect brain aging,” Bojarskaite said.

Quitting smoking can help reduce your risk.

Obesity

Maintaining a healthy weight is also an important step. “Obesity is associated with metabolic dysfunction, inflammation, and increased risk of cardiovascular disease and diabetes, which in turn affect brain health,” she explained.

Excessive alcohol consumption

It’s also essential to moderate your alcohol intake. “High alcohol intake can damage neurons directly, disrupt sleep, and contribute to nutritional deficiencies and vascular disease,” Bojarskaite said.

Later-life social isolation

Bojarskaite also noted the importance of social engagement in keeping your brain stimulated. “Loneliness and isolation are associated with faster cognitive decline and poorer mental and physical health,” she said.

Untreated vision loss

On a related note, Bojarskaite said vision loss can also reduce your ability to socialize and engage cognitively with the world, making it essential to also treat any visual impairment if possible.

Exposure to air pollution

Finally, Bojarskaite discussed the effects of air pollution.

“Emerging evidence suggests that air pollution may contribute to neuroinflammation, vascular dysfunction, and the accumulation of pathological proteins associated with dementia,” she said.

The Alzheimer’s Society adds that we do not yet know what levels of exposure contribute to risk.

Addressing all risk factors is the best way to reduce dementia risk

Concluding her comments, Bojarskaite emphasized that these factors all work together in influencing your dementia risk.

“For example, hearing loss may lead to social isolation and depression; physical inactivity increases the risk of obesity, hypertension, and diabetes; poor cardiovascular health often coexists with sleep disruption,” she said.

However, the brain does remain plastic throughout your lifespan, offering hope for prevention.

“While there is no single intervention that eliminates dementia risk, small improvements across multiple modifiable factors can meaningfully improve brain health and potentially reduce population-level dementia burden,” said Bojarskaite.