Dementia Is Not Inevitable: Nearly Half of Cases Could Be Prevented
In the summer of 2024, a panel of 27 dementia experts published one of the most hopeful findings in the field in The Lancet: an estimated 45% of dementia cases worldwide could potentially be prevented or delayed if 14 modifiable risk factors were eliminated. That was up from 40% in the group's previous report in 2020, after the commission added two new risk factors: high LDL cholesterol and untreated vision loss.
Dementia is one of the fastest-growing health challenges in the world. An estimated 57 million people were living with dementia in 2019, and that number is projected to reach about 153 million by 2050 as populations age. There is still no cure for Alzheimer's disease, and the newest drugs offer only modest benefits for people in the early stages. Prevention, then, has become a major focus.
The Lancet Commission, led by Gill Livingston of University College London, identified risk factors across the entire life course—from limited education in childhood to high blood pressure and hearing loss in midlife and social isolation and air pollution in later life. The following 10 habits are linked to a lower risk of dementia, ordered by the estimated share of dementia cases associated with each related risk factor, from largest to smallest. None of these habits guarantees protection, and genetics and age remain powerful influences. But together, they represent some of the most promising steps for long-term brain health.
1. Protect Your Hearing and Treat Hearing Loss
Hearing loss is tied with high LDL cholesterol as the single largest modifiable risk factor identified by the Lancet Commission, accounting for an estimated 7% of dementia cases. That makes protecting and treating hearing one of the most important habits for long-term brain health, particularly in midlife.
Researchers believe hearing loss may raise dementia risk in several ways: when the brain struggles to process sound, it may divert resources away from memory and thinking; hearing loss can also lead to social isolation, which is itself a major risk factor for dementia.
The good news is that treatment appears to help. The ACHIEVE trial, published in The Lancet in 2023, found that a hearing intervention, including hearing aids and counseling, slowed cognitive decline by 48% over three years among older adults at higher risk of dementia. Since 2022, the U.S. FDA has allowed adults with mild to moderate hearing loss to buy hearing aids over the counter without a prescription, dramatically lowering their cost.
Protecting hearing in the first place is just as important: turn down the volume on headphones, wear earplugs at concerts and in loud workplaces, and limit exposure to noisy environments. For adults over 50, a regular hearing test is a simple step that can catch problems early.
2. Keep Your LDL Cholesterol in Check
High LDL cholesterol, often called "bad" cholesterol, was one of two new risk factors added in the 2024 Lancet Commission report. It immediately became one of the most significant, tying with hearing loss as a factor linked to an estimated 7% of dementia cases.
Large cohort studies involving more than 1 million participants, along with a genetic analysis of 27 studies, found that people with higher LDL levels in midlife faced a greater risk of developing dementia later in life. Scientists believe high LDL cholesterol may raise dementia risk by contributing to atherosclerosis, reducing blood flow to the brain and increasing the risk of strokes.
The Lancet Commission recommends detecting and treating high LDL cholesterol starting around age 40. Lifestyle habits also play a major role: diets rich in vegetables, fruits, whole grains, legumes, nuts and fish and low in saturated fat and processed foods can help lower LDL levels. Regular physical activity, maintaining a healthy weight and avoiding smoking can also improve cholesterol profiles. Because high cholesterol usually causes no symptoms, regular blood tests are the only reliable way to know whether it's a problem.
3. Keep Learning at Every Age
The Lancet Commission identifies less education in early life as a risk factor linked to an estimated 5% of dementia cases. Education itself happens mostly in childhood and young adulthood, but the principle behind it—that challenging the brain builds resilience—applies throughout life.
Researchers believe education helps protect against dementia by building cognitive reserve, the brain's capacity to withstand damage. Continuously learning new skills, reading, learning a language or a musical instrument may help strengthen cognitive reserve at any age.
4. Manage High Blood Pressure
Midlife hypertension is an important modifiable risk factor for dementia. Long-term high blood pressure damages cerebral blood vessels, reduces blood flow to the brain and increases the risk of small, silent strokes that accumulate damage over time.
Regular blood pressure monitoring, following medical advice on medication, reducing salt intake, maintaining regular exercise and controlling weight are all effective ways to manage hypertension. Regular blood pressure checks are recommended starting around age 40.
5. Prevent and Control Diabetes
Diabetes is closely linked to increased dementia risk. High blood sugar damages blood vessels and nerves, including those in the brain, increasing the risk of cognitive decline.
Controlling blood sugar through healthy eating, regular exercise, maintaining a healthy weight and following medical advice not only helps manage diabetes but may also lower dementia risk.
6. Maintain a Healthy Weight and Avoid Obesity
Midlife obesity is one of the modifiable risk factors for dementia. Obesity often coexists with high blood pressure, diabetes and high cholesterol, all of which increase dementia risk.
Maintaining a healthy weight through balanced diet and regular exercise is an important strategy for protecting brain health.
7. Actively Treat Depression
Depression is associated with increased dementia risk. It may lead to social withdrawal and reduced activity, and may also affect brain health through physiological mechanisms such as inflammation.
If you experience persistent low mood, loss of interest or other symptoms, seek professional help promptly. Psychotherapy, medication and social support are all effective interventions.
8. Stay Socially Active and Avoid Isolation
Social isolation is an important risk factor for dementia in later life. Maintaining meaningful connections with others can stimulate the brain, provide emotional support and promote healthy behaviors.
Participating in community activities, volunteering, staying in touch with family and friends, and joining interest groups are all good ways to stay socially active.
9. Exercise Regularly
Regular exercise has multiple benefits for brain health: improving blood circulation, reducing inflammation and promoting neuroplasticity. Exercise also helps control weight, blood pressure, blood sugar and cholesterol, indirectly lowering dementia risk.
At least 150 minutes of moderate-intensity aerobic exercise per week, such as brisk walking, swimming or cycling, combined with strength training, is recommended.
10. Eat a Healthy Diet to Protect Your Brain
The Mediterranean diet and the MIND diet (which combines the Mediterranean and DASH diets) have been linked to lower dementia risk. These diets emphasize vegetables, fruits, whole grains, legumes, nuts, fish and olive oil, while limiting red meat, processed foods and sugar.
A healthy diet not only helps control weight, blood pressure, blood sugar and cholesterol but may also directly protect the brain by reducing inflammation and oxidative stress.
Start Small—It's Never Too Early or Too Late
These habits are not isolated; they are interconnected and mutually reinforcing. For example, exercise helps control blood pressure and blood sugar, social activities can alleviate depression, and a healthy diet can improve cholesterol. Research clearly shows that it's never too early or too late to start adopting these habits.
Genetics and age remain powerful influences on dementia, and no habit guarantees complete prevention. But by taking these science-backed steps, you can significantly lower your risk and build a solid foundation for long-term brain health.
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