Comment by maj0rhn | Hacker News Reader

Comment by maj0rhn | Hacker News Reader

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As always, correlation does not equal causation.

According to the abstract, the effect was significant only at a "dose" of 4 to 7 sauna visits per week in the 20 years of follow-up.

Now, I don't know much about the availability of saunas in Finland, but one must ask: what kind of person can financially afford, or make time for, 4 to 7 sauna visits per week? Even with the statistical adjustment for traditional cardiovascular risk factors, I seriously doubt that the people who use saunas frequently have the same income levels, attention to health, and all sorts of other habits as the people who never use saunas.

So I would put this study on the heap of interesting correlations that ultimately mean nothing.

BTW, they should look at the development of Alzheimer disease. There is suspicion that high body temperatures (e.g. with fever) can incite the changes in protein conformation that are thought to be essential in the establishment and progression of the disease. So, if sauna users stay a little too long, and get a little bit hyperthermic, they may be setting themselves up for Alzheimer disease. That would be a bummer.

Well, we are talking about Finland.

http://www.stat.fi/tup/suoluk/suoluk_asuminen_en.html

By the latest numbers there are 1 266 000 residential buildings in Finland, housing 1 581 000 saunas. But of course other buildings also have saunas, so in total there are more than 2 million saunas.

There are 5 451 270 people in Finland.

I'd say a lot of people have access to saunas.

A large portion of houses in finland have a sauna - it's as common as a tub (ok, I don't have exact statistics but more or less). Usually in the least apartment buildings have a common sauna. The cost of usage is neglible. Public saunas in swimming halls etc are not very expensive. The income level is not a factor (what ever the quality of the research may be)

I would think it's very uncommon for people living in apartment buildings to go to a sauna 4-7 times a week (I believe that's often not even possible due to various rules). When you add in that there's some correlation between lack of wealth and living in apartment buildings I don't think you can rule out income level that easily.

As always, correlation does not equal causation.

The article doesn't claim that it does. That's why the title was specifically constructed to use the phrase "association between" (rather than "causes" or "is caused by.")

What kind of person can financially afford, or make time for, 4 to 7 sauna visits per week?

The kind that has access to a sauna in their own home. Which is quite common in Finland, apparently: "There are five million inhabitants and over three million saunas in Finland - an average of one per household."[1]

[1] https://en.wikipedia.org/wiki/Finnish_sauna

Weird train of thought about the supposed scarceness of saunas. My gym in SF has a sauna. Many people use it every time they work out. You can only stay in there for like 10 minutes. Not a huge time investment. Are you telling me that only the very wealthy can afford an $80 monthly gym membership?

Some apartment buildings in Berlin I visited had saunas built in (and these were not luxury buildings).

My understanding is that saunas are even more prevalent in Scandinavia. You should rethink your reasoning.

$80 per month is a lot of money for most people. It's like buying a new pair of running shoes every month. Quite a luxury. This in itself separates groups of people. Reasoning stands.

"""saunas are even more prevalent in Scandinavia. You should rethink your reasoning."""

The cost of access to saunas is not zero in money, and not zero in time. This in itself creates differences between groups, which is why randomized trials are far superior to case-control or observational studies. This is so well established in medicine that there is no cause to rethink the reasoning.

Based on your comments I gather you have never been in Finland. So you know close to nothing about social mores and structures in that country. Your comments are noise, not even wrong.

Correlation means correlation, not that something is impossible. In other words, just because, for example, a poor person can afford to go to sauna 4-7 times a week it doesn't mean that there's no correlation between income level and sauna usage.

Another example would be drinking an "expensive" wine at least once a month. I'd claim that a lot of poor people can afford a $25 wine monthly, but there can still be a correlation between income and buying an expensive wine at least once a month.

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