80 comments

  • testemailfordg2 4 hours ago

    Funded by the Institute for Scientific Information on Coffee (ISIC) — an industry body — which is a notable conflict of interest the authors disclose but don't extensively discuss

    • rapidaneurism 3 hours ago

      It does not sound like an outcome that big coffee paid for it to be so:

      Behaviourally, coffee drinkers exhibited greater impulsivity and emotional reactivity, whereas non-coffee drinkers demonstrated better memory performance.

      • iammjm 2 hours ago

        Do they though? Any data on that? Also, the highly caffeinated people might also be sleep deprived, which impacts memory and emotional regulation

        • Antibabelic 2 hours ago

          The data is in the linked paper. It's a direct quote from the abstract.

        • oharapj 40 minutes ago

          Please delete this comment. It’s embarrassing

      • selcuka 3 hours ago

        > It does not sound like an outcome that big coffee paid for it to be so:

        Who said anything about big coffee? These guys might be a secret, anti-coffee organisation. /s

        • fedeb95 2 hours ago

          it's the barley cartel.

    • carabiner 3 hours ago

      Every damn time, for chocolate, coffee, and red wine "studies."

  • TazeTSchnitzel 3 hours ago

    After habitually consuming caffeine (not in coffee form) daily, usually multiple times a day, for more than a decade, a horrible mental health incident happened to me that forced me to stop it for a while. Afterwards I didn't resume the habit, and so I no longer have a tolerance.

    This has let me evaluate what caffeine does with fresh eyes, so to say, because I can now consume it occasionally while having many non-caffeinated days to compare to. It's a profoundly psychoactive substance and does a lot of things to cognition. I guess I have decided I don't enjoy how it feels, having previously been dependent on it.

    • bayarearefugee 17 minutes ago

      Quitting caffeine after decades of use was a bit of a mixed bag for me in the short term, but positive in the long term.

      Going caffeine-free made it much easier to lose weight as I have far less cravings for high carbs and sugar now, presumably this is related to the impulsivity impact talked about in the paper.

      Going caffeine-free also made me very depressed for a while with severe anhedonia, this lasted way longer (like 3-4 months) than one would generally expect for caffeine withdrawal symptoms.

      I had seemingly become so used to the increased dopamine signaling while buzzed on caffeine that my brain was a mess for a rather extended period of time as it got used to not having it.

      Overall I view quitting as a positive for me, but I'd warn anyone thinking about doing it to do it carefully and closely monitor their mental health. AFAIK the impacts of quitting can be quite different for different people, so my experience may differ than that of others, but I had no idea how much of a (temporary) mental health crash quitting caffeine could cause until I experienced it.

    • BatteryMountain 2 hours ago

      I've had the same experience. Caffeine is super addicting, the ritual & habits surrounding it is a potent pull. For myself, it makes me erratic, impulsive, more reactive and agitated. One cup a day puts me on edge, makes me sweat more, makes me more intolerant, makes everything feel too slow. It such a sneaky drug and it can really get under your skin without you realizing how much it changes you.

    • apples_oranges an hour ago

      Agree, I drink it a lot and then stop drinking it at least once a year for a few weeks, and for sure it's a different mode of mind, but can't really qualify it besides that I remember my thinking being softer, calmer and perhaps even "more correct" without coffee.

      (But I never had any mental-health incidents, and I drink a lot of it, more than all people that I personally know.)

    • barrenko 2 hours ago

      Coffee is a plant demon that created the western civilization as we know it today...

      • fermiNitambh 9 minutes ago

        I like this worldview. Prior to coffee, Europe was in the grip of the beer dwarves. Coffee demons took over and invented nationalism, capitalism and Keynesian economics.

    • kakacik 13 minutes ago

      I do believe a lot of it boils down to tolerance. I for example feel basically 0 effects, and drink it just because I like the taste (of a good one with milk, or exceptionally some good espresso / ristretto after big dinner).

      I recently traveled and didn't have coffee for more than a week. No change I could feel, no craving, nothing. But one of my ex-gf was quite sensitive on many things, had frequent headaches, low blood pressure and coffee was helping with those visibly. So YMMV.

    • readthenotes1 3 hours ago

      Notably, the article is looking at coffee, both caffeinated and decaffeinated. There is a lot more to coffee than just caffeine...

      • mixedCase 2 hours ago

        The overwhelming majority of the enjoyable coffee experiences are caffeinated. While there is good decaf out there it's not the norm, specially in smaller markets.

        • tsimionescu 22 minutes ago

          I think they meant that coffee contains a lot of other compounds than just caffeine, which something like energy drinks or teas will not include. So you can't necessarily extend conclusions from a study on consumption of coffee to effects that other drinks that happen to include caffeine might have.

          Edit: this is especially relevant here, as the study found similar effects in decaffeinated coffee drinkers. So the effects they observed, if real, are not related to caffeine.

    • rimliu 2 hours ago

      How do you know that caffeine was the cause?

      • ivan_gammel 2 hours ago

        This of course cannot be generalized, but withdrawal is quite noticeable for personal well-being in a positive way.

  • fedeb95 2 hours ago

    thirty-one participants were moderate coffee-drinkers (CD, i.e., people that usually consume between 3 to 5 cups of coffee per day).

    3-5 is moderate? To me, 3 is already high.

    Also, sample size is pretty low and they're all Irish.

    • p4bl0 44 minutes ago

      I agree. I'm deep into specialty coffee and I love making and drinking coffee a lot, but three cups is already higher than what I drink on a normal day. Also, most of the time when I go above this threshold, I drink decaf.

    • midtake 16 minutes ago

      Are the Irish unique when it comes to metabolizing coffee?

    • alexey-salmin an hour ago

      I do 6-10 espresso cups per day, so 3-5 does sound very moderate.

      • andor 8 minutes ago

        It depends on how much caffeine is in your cup. Rather than measuring the size of a cup, I would go by the amount of coffee, as in the weight of the beans, used to brew it. The actual amount of caffeine is not as easy to measure, and even for the same kind of beans, there is natural variation.

        For a traditional Italian espresso, about 7g of coffee beans are extracted. For a third-wave double espresso, it's usually 18g or more.

        In my opinion, 10x7g is a lot. 2x12g is more than enough for me.

      • MagicMoonlight 20 minutes ago

        That’s not normal. It’s like saying “I drink 6-10 beers a day so 3-5 is very moderate”

  • pinkmuffinere 4 hours ago

    I’m super interested in this sort of study! However, it looks like n=62 here, which I think weakens the results —they’re probably just useful as suggestions of possible effects. Also, any food is expected to have similar effects on the microbiome. They didn’t test caffeine in isolation. In some ways that’s better (I don’t consume caffeine in isolation), but in some ways that’s less useful (it’s possible you get similar results from many random vegetables)

    • sixtyj 4 hours ago

      In 1995, NASA did spiders experiment. Caffeine is a siginificant impulsivity trigger. :)

      https://rarehistoricalphotos.com/nasa-spiders-drugs-experime...

      • ivell 2 hours ago

        LSD has unconnected strands in the air. I guess this is expected.

        • dotancohen an hour ago

          The LSD and sleeping pills were not in the original study I believe. That might be an artists representation of the image at the bottom of the original study, which I remember showed the results in a single row.

      • jayd16 3 hours ago

        Nice web, Mr. Crack spider.

    • bhaney 4 hours ago

      > They didn’t test caffeine in isolation

      But they did test both caffeinated and uncaffeinated coffee, and found the same effects in both, indicating that the effect is caused by something in coffee other than the caffeine

      • krige 4 hours ago

        Doesn't decaf also contain caffeine, just a lot less of it?

      • anon84873628 3 hours ago

        Typical extraction yield is 18-20%. For a 20g dose that's 4g of material consumed, or about 30 individual beans.

        I wonder if you could find similar effects with 4g or broccoli sprouts, or garlic, or ginger, or cumin seed, shiitake mushroom, seaweed, soursop leaf, or...

  • satvikpendem 4 hours ago

    What's cool is this effect exists even in decaf coffee, as someone who primarily drinks decaf black, for flavor and for a good night's rest as I'm sensitive to caffeine.

    • Kelteseth 3 hours ago

      What kind of decaf coffee do you drink? There are differences between the cheap chemical Methylene way to create decaf coffee and the expensive co2 way to get rid of the caffeine.

      https://cleanlabelproject.org/wp-content/uploads/CLP-Decaf-C...

      • Schlagbohrer 2 hours ago

        Is that methylene way even legal? It basically uses petroleum fuel in the process right? I assume it was outlawed a long time ago but that might be extreme naievete for US regulatory capability...

        • eichin 2 hours ago

          https://www.thedecafproject.com/ (Dec 2024) let you order matching swiss water, CO₂, and Ethyl Acetate (sugar cane byproduct) decaffeinated coffee from the same batches of beans. The EPA banned methylene chloride earlier in that year, but because of toxicity to workers, not because of risk from the resulting coffee itself (and it looks like the FDA didn't ban it.) So I guess you couldn't make decaf with it in the US but you could probably still import and sell it?

      • satvikpendem 3 hours ago

        I don't buy the methylene processed ones, generally it's Swiss water processed or like you said the CO2 processed ones.

  • ANarrativeApe 2 hours ago

    It would have been interesting to see if there was any difference relating to CYP1A2 (Cytochrome P450 1A2), the fast metabolizers and the slow metabolizers.

  • therealdeal2020 an hour ago

    good thing I have claude to summarize this and quickly realized that sample size was small and nothing much new unless you are a microbiome researcher

    • reliablereason 12 minutes ago

      If the effect size is big small sample sizes does not matter as much as otherwise.

      You really have to look at the power analysis and the sample size together.

      Saying this as a general truth. I am not sure about the power of the method in this papper, i only read the abstract.

  • xingyi_dev 29 minutes ago

    Whatever the case, a cup of coffee is basically what kickstarts my day.

  • reedf1 4 hours ago

    At least subjectively, coffee seems to help my memory. But maybe that's why I started drinking coffee?

    I would probably drop coffee it was proven to have negative effects on memory.

    • bboozzoo 4 hours ago

      > But maybe that's why I started drinking coffee?

      you don't remember why, do you?

  • shinryuu an hour ago

    Would be real interesting to see a similar study on tea.

  • wjnc 4 hours ago

    I have not much followed the science of gut microbiome and psychology. Is this really going where this article is pointing? That we can tease out causation in foods and habits via gut microbiome towards behavior and psychology? Pretty rad.

    • chneu 4 hours ago

      There's a decent amount of research going into the hormones that our GI biome produce and how it affects us. Our body has a few different biomes and they all seem to play somewhat important roles.

    • colechristensen 4 hours ago

      Yeah there's nontrivial evidence that among other things, the complex community living inside you manipulates your brain.

      • ButlerianJihad 4 hours ago

        My psychiatrists agree that “hallucination” (in lay terms: “hearing voices” or “seeing things”) only refers to things that aren’t real.

  • getnormality 5 hours ago

    Coffee modifies physiology and cognition? You're telling me this for the first time.

    • alecco 4 hours ago

      The paper is about previously unknown ways coffee affects the body.

    • ButlerianJihad 4 hours ago

      I was so surprised at this headline that I nearly leapt out of my chair!

      • jonplackett 3 hours ago

        But it says it’s the same for decaf. That is more interesting

        • aitchnyu 2 hours ago

          Been treating coffee as caffeine with aroma. Any important points about coffee itself?

    • triage8004 4 hours ago

      Humans known since 45 minutes after first drink

  • sdevonoes 2 hours ago

    I must be weird, but coffee (or caffeine) doesn’t really “wake me up” in the mornings and I could drink it in the night and still sleep well. Because of that I don’t drink coffee; I prefer tea

    • vjerancrnjak 2 hours ago

      I think this description is often associated with ADHD memes.

      Falling asleep after a can of energy drink.

    • fedeb95 2 hours ago

      tea also has caffeine, although in smaller quantities. Maybe you mean that you don't care so you go by taste, just specifying because there's a common misconception about tea not having caffeine.

      • Lionga 2 hours ago

        Some tea has caffeine, most has don't.

        • pasquinelli 2 hours ago

          all tea has caffeine unless it's decaf. some things that aren't tea are called tea casually, but they aren't tea, for instance peppermint "tea" is not tea. by the same logic that one would call peppermint a tea, one would have to call coffee a tea. and beef broth.

          • majkinetor an hour ago

            That depends on culture. All camelia s. teas have it (green etc) but almost none of common herbal teas in Europe have it (chamomile, menta, sage etc.) They are not called casually teas.

            • pasquinelli 39 minutes ago

              > They are not called casually teas.

              are you saying chamomile isn't called tea but it's one of the teas without caffeine? if so that's very confused.

              camelia sinensis is tea. when i said that other things are casually called tea, i mean that what chamomile tea, for example, ought to be called is a tisane or an herbal infusion. casually, people might call it a tea; some people are so casual about it that they think it actually is tea. but it isn't.

  • poly2it 4 hours ago

    > ... reintroduction triggered acute microbiome changes independent of caffeine.

    This sounds interesting. I've never really considered the constituents of coffee other than caffeine and what unique effects they may bring.

    I wonder if I would experience behavioral effects if I replaced my coffee intake with caffeinated non-coffee drinks or pills?

    • kulahan 4 hours ago

      Studies seem to indicate that coffee is at least as healthy, if not healthier than tea, and I have not heard this about caffeine specifically (aka the same effects coming from pills or energy drinks).

      One fun fact: we still haven’t figured out why coffee makes us poop. We’ve studied every chemical in there and can’t seem to find a link, but the association is uh… well-known.

      • hermitcrab 2 hours ago

        >why coffee makes us poop.

        That seems to vary wildly between individuals. It doesn't have that effect on me.

  • neya 5 hours ago

    The only good thing that keeps me from collapsing into a state of limbo is coffee and now, even that's bad (seems more like a mixed bag, but still)? Sigh.

    • cyberpunk 3 hours ago

      Maybe I have some neurological issue or something but whenever I quit coffee I find it extremely difficult to maintain any kind of motivation to sit in an open plan office and code. Coffee makes me a worker bee, I can understand why employers give it away for free.

      So, the coffee stays for now.

      • neya 3 hours ago

        Yeah, exactly. I can totally relate to this. I have actually monitored my productivity on an excel sheet and the days with coffee win by a large margin. I am not sure if it's withdrawal symptoms on the days without, though.

    • anon84873628 4 hours ago

      Don't fret. You're allowed to enjoy things that aren't part of the scientific reductionist longevity influencer lifestyle fad :)

      • antonvs 3 hours ago

        Nitpick: What you’re referring to is not scientific.

    • bee_rider 5 hours ago

      There have been positive and negative reports for a long long time. If coffee was going to kill us, I’d certainly have died in school!

    • kulahan 4 hours ago

      Coffee in general is unreasonably healthy as a beverage. The overwhelming majority of science agrees it’s a quality health drink.

      • modo_mario 2 hours ago

        Non-industry funded science?

    • hermitcrab 2 hours ago

      Relax. Tomorrow there will be a paper/article saying coffee is great for you.

    • fransje26 an hour ago

      Did you know:

          By replacing your morning coffee with herbal tea, you can remove up to 87% of the little joy you still have left in your life.  /s
      
      Keep the coffee buddy.
  • 6LLvveMx2koXfwn 4 hours ago

    "These findings reveal previously unrecognised effects of coffee on the microbiota–gut–brain axis, suggesting that microbiome profiles could potentially predict coffee consumption patterns", or, perhaps, just ask the patient?

    • raincole 4 hours ago

      Could you elaborate on how to interpret your comment without it leading to anti-intellectualism?

    • colechristensen 4 hours ago

      You are missing the point.

      If you can predict someone's coffee intake based on testing of their microbiome then you've proven that coffee intake has predictable effects on the microbiome.

      The important part isn't predicting coffee use, it's just the proof that there's you can predict and perhaps control in the opposite direction leading to more research.