[martamorena2]

There very likely is zero correlation. But potentially, people who take cold showers represent a biased subset of the population, which is statistically more inclined to look young.

This applies to pretty much EVERYTHING that is not done via high quality double-blind studies published in reputable, peer-reviewed journals.

Point being: Repeating single actions of successful people statistically does not make you successful.

[jiggawatts]

Why is this being downvoted?

As an example, there was a study that eating a handful of almonds every day is correlated with a bunch of positive health outcomes. Then a follow-up paper determined that this is simply because nuts are a relatively expensive snack, so they're eaten regularly mostly by wealthier people. It's well established that being poor is bad for your health, and conversely being rich tends to allow healthy lifestyles in general.

The kind of people that take cold showers are the "health-nut" types that prioritise healthy living over comfort. They're a rare, self-selecting subset of the general population.

It's extremely difficult to do good science based on statistics of self-selecting groups, or groups highly correlated with wealth.

[vuciv1]

That absolutely makes sense. Correlation is not causation.

I would probably be characterized as one of the "health-nuts," so between the cold showers, moisturizing twice a day, trying to perfect my indoor air pollution, and literally eating raw spinach and a bowl of fruit for lunch... Who knows what contributes to what?

I probably have health anxiety. I wouldn't characterize it as extreme, but it does force me to do anything I hear is healthy for me.

[gchamonlive]

Correlation can arise without necessarily having a cause and effect relationship. In this case it is quite plausible to have a correlation between longevity and cold showers, but that could be because people prone to cold showers are also more likely to face discomfort and lead more active lives, which in turn has direct correlation with a reduced risk of heart disease and diabetes. Then the point changed entirely, where once the focus was on the showers, now it is on something far deeper, like the hability to be comfortable with discomfort.

[majkinetor]

Here are some studies I collected years ago:

- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5025014/

- https://pubmed.ncbi.nlm.nih.gov/24921042/

- https://www.medicalnewstoday.com/mnt/releases/239174#1

- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2370378/pdf/can...