Risk and Resilience
Two ends of the same scale
Resilience is not a separate quality that some people happen to have. It is what lower risk looks like from the other direction, the same measurement read from the opposite end. Every person starts somewhere on that scale and keeps moving along it, pushed by who they are and by where they live.
Genetics and early life set a starting position. Behaviour and community conditions move it from there. Nobody occupies either extreme, and no position is permanent.
Individual factors that shape your risk and resilience
Age, genetics, sex, and the conditions you live with differ from person to person. A few of them cannot be changed. Most are ordinary health problems that respond to treatment.
Age and genetics. Age is the largest risk factor and nothing modifies it. The main genetic variant, APOE-e4, raises the odds without deciding the outcome: many carriers never develop dementia.
Sex. Women carry greater lifetime risk, partly because several modifiable factors are more common in women and weigh more heavily on their cognition.
Other health conditions. Diabetes, blood pressure, cholesterol, obesity, depression, and untreated hearing and vision loss all sit on the Commission's list. Unlike the factors above, these are treatable.
Community factors that shape your risk and resilience
Where a person lives, works, and grows up shapes brain health as much as anything they carry. These conditions decide how much of the list above is actually within reach.
Social and economic conditions. Policy, income, housing, and discrimination based on age, race, ethnicity, gender identity, sexual orientation, and disability all shape brain health outcomes.
Environmental exposure. Air pollution accounts for an estimated 3% of dementia cases worldwide, and it is determined by where a person lives rather than by anything they do.
Access to education and care. Limited early education carries 5% of population risk. Hearing aids and blood pressure control only lower risk for people who can afford and reach them.
The two levels are intertwined
Studying one without accounting for the other ignores a large share of what drives health and health outcomes.
Race and ethnicity. Of adults who reach 65, an estimated 38% of Black adults and 35% of American Indian and Alaska Native adults develop dementia within 25 years, against 30% of white adults. These gaps are not biological. They track unequal access to education, healthcare, and clean air across a lifetime.
Education. Limited early education is counted as an individual risk factor, but school funding, neighbourhood, and policy set it long before a person can influence it.
Treatable conditions. Hearing loss, blood pressure, and diabetes are personal diagnoses. Whether they actually get treated depends on insurance, distance to a clinic, and whether care arrives in your language.
Across a Lifetime
Risk builds up in stages
The Commission's fourteen factors are spread across the whole of life, and different ones carry the most weight at different points. Dementia risk starts accumulating decades before anyone would think to worry about it, and each stage still offers something to act on.
Early life
Up to about age 45
Building the reserve that gets drawn on later.
- Limited access to education5%
Midlife
Roughly ages 45 to 65
The heaviest stretch. Ten of the fourteen factors sit here, which makes midlife the widest opening to act.
- Untreated hearing loss7%
- High cholesterol7%
- Depression3%
- Head injury3%
- Physical inactivity2%
- Diabetes2%
- Smoking2%
- High blood pressure2%
- Obesity1%
- Heavy alcohol use1%
Later life
Age 65 and beyond
Where connection, environment, and the senses carry the most weight.
- Social isolation5%
- Air pollution3%
- Untreated vision loss2%
Each percentage is the share of dementia cases worldwide that could potentially be avoided if that one factor were eliminated. Together the fourteen come to 45%. Hearing loss and cholesterol carry the most weight of any single factor, and both are treatable.
Having one or more of these does not mean a person will develop dementia, and avoiding them is not a guarantee against it. These are population-level patterns, not individual predictions.
What Protects
Building a brain healthy life
Nearly every modifiable risk factor has a protective counterpart. None of these is a guarantee, but each one shifts the odds, and adopting several together shifts them further.
Sustained social connection
One of the most consistent protective signals in the research, and one of the most commonly overlooked.
Treating what's treatable
Hearing aids, blood pressure control, and diabetes management are dementia prevention measures, even though they are rarely described that way.
Regular physical activity
At any intensity a person can sustain. The benefit shows up in blood flow, sleep quality, mood, and brain structure at once.
Lifelong learning and novelty
Challenging, unfamiliar mental activity appears to add to reserve well into later life.
Protected sleep
Deep sleep is when the brain clears metabolic waste it produces during the day.
Care that reaches people
Prevention that is not accessible, affordable, or offered in a person's language is not prevention.
What Has Been Tested
Multidomain prevention works. How much, and for whom, is still open
Two randomized trials went further and tested whether deliberately changing several factors at once actually helps. Both compared active approaches in people already at elevated risk, so neither tests prevention against doing nothing.
FINGER
Finland, 2015
1,260 adults at elevated risk. Two years of diet, exercise, cognitive training, and vascular monitoring protected thinking better than general health advice did. The difference was statistically significant and small.
US POINTER
United States, 2025
2,111 adults across five US sites. A structured program and a self-guided one both improved cognition, the structured one more so, and the benefit held for people carrying the APOE-e4 variant.
Resilience
Risk is not destiny
Some people carry substantial brain changes and keep thinking clearly for years. What that resilience is made of is still largely unknown, and finding out is what this study is for.