Study links coffee consumption to metabolic health and sex hormones

______k about 2 hours ago 48 commentsRead Article on oulu.fi

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Discussion (48 Comments)Read Original on HackerNews

zetazzed•about 2 hours ago

I'm a good target market for pro-coffee writing, but this is just an observational study of a drinks habit. No one in the general public should have any interest in studies of this kind.

Maybe if you're deep in working in this research space it could help generate hypotheses for more meaningful research? But "we cross sectionally compared two groups with different behaviors and found they were different" is not really a result.

al_borland•about 2 hours ago

The endless articles about studies that are pro-coffee make me highly skeptical. They all feel like advertising by the coffee industry to help coffee addicts feel good about their habit instead of feeling like they should cut back.

designerarvid•about 1 hour ago

Either point out weaknesses in the study, or dubious funding behind it etc. Or just stick with saying that you prefer tea.

pazimzadeh•about 1 hour ago

it could be that coffee acts directly on the endocrine system as they suggest, or coffee allows you to work out longer (or work out at all since you don't want to sit still) which leads to the effects they observed

I'm curious why they single out coffee vs. tea, are they suggesting it's not the caffeine itself that's doing it?

mc32•about 1 hour ago

Or possibly one of those who stick to only water.

blinkbat•about 1 hour ago

AmishNews

embedding-shape•about 1 hour ago

> coffee addicts

I don't know if it's the word "addicts" that maybe doesn't have to be a negative, or if it's not the right word at all for "functional addicts", but I feel like the "addiction" people have to coffee is much more behavioral than chemical (although there is physiological withdrawal symptoms too), compared to other "harder" drugs like cocaine or heroin. The clear negative effects from long-term use is also a lot much evidence with one side of these, coffee not so much.

Not sure you have to cut back on something that you really enjoy, so much that you wanna do it every day, even if you get cranky when someone (sometimes you) ruin this ceremony for you. Why would you cut back when the biggest negative is spending 10-20EUR a month on some nice coffee you can consume every single morning?

brokencode•about 1 hour ago

Why should they feel like cutting back? Where’s the evidence that it’s bad for you?

KPGv2•about 1 hour ago

I feel that way about the endless studies showing fiber is important for health, too. Because there's no way studies re-confirm findings because they're revealing truth. It's definitely Big Leaf at work.

eiriklv•about 2 hours ago

High SHBG and lower free hormones isn't a good thing usually. Starving and anorexia (as an example) can make your SHBG levels skyrocket, resulting in low free hormone levels.

throwaway2037•about 1 hour ago

Here is the original study: https://link.springer.com/article/10.1007/s00394-026-04038-z

Weirdly, I cannot copy text from that page. What am I doing wrong?

Regardless, here is the result summary:

    > Higher coffee intake groups showed lower total and visceral fat and higher skeletal muscle mass, while BMI was comparable across groups. Inverse correlations were observed between coffee intake and circulating branched-chain amino acids (BCAAs) in both sexes. In men, higher coffee intake correlated with a more favourable glucose-insulin profile. Multivariable-adjusted models revealed a distinct hormonal pattern: positive associations with total testosterone (β = +0.29 nmol/L per cup/day), bioavailable testosterone, and sex hormone-binding globulin (SHBG), alongside inverse associations with free testosterone and the free androgen index (FAI). In women, hormonal associations were more limited, with positive associations for SHBG and inverse associations for free testosterone and FAI.

This part: "positive associations with total testosterone (β = +0.29 nmol/L per cup/day)". For testosterone, 1 nmol/L ≈ 28.8 ng/dL. So: +0.29 nmol/L ≈ +8.4 ng/dL per additional cup/day.

Really, this will have no meaningful impact on your health. It is widely discussed by TRT (testosterone replacement therapy) doctors that supplements that can increase your total test by 100ng/dL will have no meaningful impact. Literally, you need to drink 12 cups of coffee per day to get a ~100ng/dL improvement. You are going to have a lot of second order effects from drinking 12 cups of coffee per day! I would never recommend it.

asdfasgasdgasdg•about 1 hour ago

Love coffee, drink it every day. This study is just as useful as other studies that correlate coffee with negative outcomes. Which is to say, it’s a study that just shows some correlations. Causation is not particularly likely. Drink coffee if you like it but don’t expect health benefits or harms.

derektank•about 1 hour ago

I wonder if the mechanism of action here is increased caffeine consumption resulting in more/longer duration/higher intensity exercise.

delduca•about 1 hour ago

Only if it’s coffee from Brazil :-)

unselect5917•about 2 hours ago

Something I learned years ago: caffeine doesn't directly "wake you up" it merely causes a trickle of adrenaline release.

So I'm guessing you could get the same boost from exercise, probably moreso.

Anything that elevates the heart rate for a bit is generally good for humans.

n8henrie•about 1 hour ago

This is not the mechanism by which caffeine promotes wakefulness.

RobLach•about 1 hour ago

That's totally wrong.

For one, caffeine is a known adenosine antagonist. The effects of adenosine is described as "drowsiness" or "relaxed".

u1hcw9nx•about 1 hour ago

This was not a caffeine consumption study.

BrandoElFollito•about 1 hour ago

I like coffee and drink about 5 to 7 Nespresso capsules a day. Except when I forget, or have no access to coffee.

I did not notice any change between these two extremes.

amelius•43 minutes ago

I also drink a lot of coffee and I really hate it when I'm visiting a client and they offer me only 1 or 2 cups of coffee during the day!

moojacob•about 2 hours ago

Maybe because the other way to get Caffine is in drinks full of corn syrup.

nemomarx•about 2 hours ago

You can get corn syrup free monsters everywhere. Or those 5 hour ones, or Celsius or whatever.

The reason to prefer coffee is that it tastes less aggressive than those I think

BeetleB•about 1 hour ago

Coffee tastes more aggressive than all of those.

llm_nerd•about 2 hours ago

The study links it to better metabolic health. Did you assume it meant worse?

bjt•about 2 hours ago

I think they're saying that coffee is a healthier habit than soda.

andai•about 2 hours ago

Title sounds terrible, but the effects are positive from what I understood?

thih9•about 2 hours ago

Not effects, just observations, as the article also states.

plastic-enjoyer•about 2 hours ago

So, that's why I am horns all the time

rzzzt•about 2 hours ago

"Higher coffee consumption was linked to a more favourable glucose–insulin profile, higher concentrations of total and bioavailable testosterone, and increased levels of sex hormone-binding globulin (SHBG). At the same time, free testosterone and the free androgen index were modestly lower. In women, hormonal associations were more limited and were primarily characterised by higher SHBG and lower measures of free androgens."

- Total testosterone = free + bound to albumin + bound to SHBG

- Bioavailable testosterone = free + bound to albumin

- Free testosterone = free (not bound to any protein)

...aaaand now I got a mild headache. Is this good or bad? Is this why the title says "links" and not "promotes" or "inhibits" or any other word with a concrete negative or positive connotation?

thih9•about 2 hours ago

Obligatory reminder about correlation != causation, as indicated in the article itself:

> However, as this was an observational study, the findings demonstrate associations rather than cause-and-effect relationships.

More: https://en.wikipedia.org/wiki/Correlation_does_not_imply_cau...