🔗 Causal Links
The 2024 Lancet Commission identified 14 conditions and exposures that directly raise your dementia risk. These are the causal links — the "why" behind dementia. Understanding them helps you know what to watch for and manage.
The 14 Modifiable Risk Factorsstrong evidence
These are the specific health conditions and exposures that research has linked to higher dementia risk. Two new ones were added in 2024: high cholesterol and untreated vision problems.
High Blood Pressurestrong evidence
Untreated high blood pressure in midlife damages the small blood vessels in the brain, leading to reduced blood flow, white matter damage, and a leaky blood-brain barrier. This lets harmful proteins and immune cells into brain tissue. Treating hypert…
Hearing Lossstrong evidence
Untreated hearing loss is the single largest modifiable risk factor — responsible for 7% of all dementia cases globally. When you can't hear well, your brain works overtime to process sounds, leaving less capacity for memory and thinking. It also lea…
High Cholesterolstrong evidence
High LDL cholesterol in midlife was newly added to the 2024 Lancet report as a major risk factor (7% of cases — tied with hearing loss). Cholesterol contributes to vascular damage in the brain and may directly affect amyloid processing. Statins and l…
Diabetes & Metabolic Healthstrong evidence
Diabetes raises dementia risk through insulin resistance, chronic inflammation, and vascular damage. Some researchers call Alzheimer's "Type 3 diabetes" because the brain becomes insulin-resistant. The same enzyme that clears insulin also clears amyl…
Depressionmoderate evidence
Depression accounts for about 3% of dementia cases. Chronic depression raises cortisol levels, which can shrink the hippocampus (your memory center). It also reduces social engagement and physical activity. Whether depression is a true cause or an ea…
Obesitymoderate evidence
Obesity in midlife (not late life) is linked to higher dementia risk, primarily through its connections to diabetes, hypertension, inflammation, and sleep apnea. Maintaining a healthy weight through diet and exercise reduces multiple risk factors sim…
Head Injuriesstrong evidence
Traumatic brain injuries, even mild concussions, increase dementia risk — especially with repeated impacts (athletes, military, falls). Each concussion compounds the risk. Prevention is key: wear helmets, use seatbelts, prevent falls at home (remove …
Smokingstrong evidence
Smoking contributes to oxidative stress, inflammation, and vascular damage in the brain. The good news: risk starts dropping significantly within 5 years of quitting and continues to decline over time. It's never too late to quit.
Air Pollutionmoderate evidence
PM2.5 air pollution is linked to 14-17% higher dementia risk. Fine particles can cross from your lungs into your bloodstream and promote brain inflammation. On bad air quality days, exercise indoors. Consider a HEPA air purifier for your bedroom. Wal…
Social Isolation & Lonelinessstrong evidence
Being chronically lonely increases dementia risk by 32%. Social isolation (physically being alone) raises it by 26%. These are as harmful as smoking or obesity for your brain. The key is meaningful connection — even phone calls and video chats count.…
Vision Lossmoderate evidence
Newly added to the 2024 Lancet report. Untreated vision problems reduce cognitive stimulation and increase fall risk and social isolation. Cataract surgery has been linked to reduced dementia risk. Get regular eye exams and address vision problems pr…