Sauna and dementia risk: the research
By the Find My Sauna team·
Updated ·
6 min read
A few years ago a Finnish research group reported that men who used a sauna most days were far less likely to develop dementia. It's an encouraging finding and it has been widely shared. Here's what the studies actually measured, what a later, larger study found, and why nobody can yet say a sauna protects your memory.
The short answer
A Finnish study of 2,315 men, published in Age and Ageing, found that those who used a sauna 4–7 times a week were 66% less likely to be diagnosed with dementia and 65% less likely to be diagnosed with Alzheimer's disease over about 20 years than men who went once a week. A larger 2020 study of Finnish men and women found a smaller link that faded over time. These studies show an association, not proof. Nobody has tested whether starting to use a sauna lowers your risk.
The first study
The paper appeared in the journal Age and Ageing in 2017. It came from the Kuopio Ischaemic Heart Disease Risk Factor Study, which recruited 2,315 apparently healthy men aged 42 to 60 in eastern Finland between 1984 and 1989.
The men reported how often they used a sauna. Over a median follow-up of 20.7 years, 204 were diagnosed with dementia and 123 with Alzheimer's disease. The researchers adjusted for age, alcohol, weight, blood pressure, smoking, type 2 diabetes, previous heart attack, resting heart rate and cholesterol. Compared with once a week:
- 4–7 times a week was linked to a 66% lower risk of dementia and a 65% lower risk of Alzheimer's disease.
- 2–3 times a week was linked to a 22% lower risk of dementia and 20% lower risk of Alzheimer's, but these smaller differences could have been chance.
In the related heart study of the same 2,315 men, only 201 used the sauna 4–7 times a week, so that headline number rests on a fairly small group.
A larger study with women
In 2020 a different Finnish team, writing in Preventive Medicine Reports, looked at 13,994 men and women aged 30 to 69 from the Finnish Mobile Clinic Health Survey. They were followed for 39 years, and 1,805 were diagnosed with dementia.
People who used a sauna 9–12 times a month had a lower risk of dementia than people who went fewer than four times a month or not at all:
- during the first 20 years of follow-up, the risk was 53% lower
- over the whole 39 years, it was 19% lower
That pattern is worth noticing. The link was strong in the first two decades and much weaker over the full period. Sauna habits were only asked about once, at the start, and people's habits change over 39 years. Still, the bigger study backs the direction of the first one, with a more modest size.
The link with stroke and blood pressure
The same Kuopio research has linked frequent sauna use to a lower risk of stroke (61% lower with 4–7 sessions a week, in a 2018 study of 1,628 men and women) and to a lower risk of developing high blood pressure. High blood pressure and stroke are both thought to raise the risk of dementia by harming the brain's blood supply. So one theory is that whatever is good for blood vessels may also be good for the brain. See sauna and blood pressure and sauna and heart health for those studies.
Why heat might matter
Researchers have suggested a few reasons, none of them proven:
- Blood vessels. Regular heat may keep arteries more flexible and blood pressure lower, protecting the small vessels in the brain.
- Inflammation. The Kuopio researchers list lower inflammation as one possible pathway. Long-term inflammation is thought to play a part in dementia.
- Relaxation and company. A regular, sociable, calming habit may be good for the brain in ways that are hard to separate from the heat.
The limits
- It's observational. The studies recorded habits and outcomes. They can't show the sauna caused the difference.
- Reverse causation. Dementia develops slowly, often over many years before diagnosis. People in the early stages may stop going to the sauna, which would make sauna users look healthier.
- Healthier people may go more. The researchers adjusted for many risk factors, but things like education, income and social life can still slip through.
- Finland only. Both studies were in Finland, where saunas are part of ordinary life. Results may differ elsewhere, and in infrared saunas.
- The first study was men only, and its strongest result comes from a small group.
The honest summary: two Finnish studies point the same way, and that's encouraging. It's not enough to say a sauna prevents dementia.
What we know protects the brain
If you're worried about dementia, the things doctors already recommend have far more evidence behind them than any sauna: keeping your blood pressure in check, staying physically active and not smoking. A sauna habit can sit happily alongside all of these, and it may even help you keep some of them. For more on what heat does for the body, see sauna benefits.
Sauna safety in later life
Older people can enjoy saunas, but a few things matter more with age:
- Stand up slowly. Blood pressure dips in the heat, and falls on wet floors are a real risk.
- Keep rounds shorter and sit on a lower, cooler bench. Our guide to how long to stay in a sauna has sensible times.
- Drink water before and after, even if you don't feel thirsty.
- Go with someone if you have memory problems or are caring for someone who does. A person with dementia may not notice or say that they're too hot.
Who should be careful
Check with a doctor first if you have a heart condition, unstable or very high blood pressure, have recently had a heart attack or stroke, or take medicine that affects blood pressure or sweating. Never use a sauna after drinking alcohol, and leave if you feel dizzy, sick or confused.
This guide is general information, not medical advice.
Where to find a traditional sauna
Find My Sauna lists 2,616 places with a Finnish-style sauna, the kind used in the research. These cities have the most:
Kaukajärven sauna
Tampere · Finnish sauna
Kuusijärven saunat
Helsinki · Finnish sauna
Kalma Saun
Tallinn · Finnish and steam sauna
Frequently asked questions
Does a sauna reduce the risk of dementia?
Two Finnish studies link frequent sauna use to a lower risk of dementia. They show an association, not proof that saunas prevent it.
How often did people use the sauna in the dementia study?
The strongest link was in men who went 4–7 times a week, compared with once a week. In the larger 2020 study it was 9–12 times a month.
Is a sauna good for Alzheimer's disease?
In the 2017 Finnish study, men who used a sauna 4–7 times a week were 65% less likely to be diagnosed with Alzheimer's. There is no evidence that a sauna treats Alzheimer's in people who already have it.
Can people with dementia use a sauna?
Some can, with care. They may not notice they are overheating, so they should not go alone, and a doctor should be asked first.
Does the research apply to women?
The first study included only men. The 2020 study included men and women and found a smaller link.
