Note that as the trial is described, the blinding was only related to the presence or not of caffeine. There wasn't any "non-coffee" placebo (something with the taste but none of the components of coffee). (Of course it is certainly difficult to make something taste like coffee while being as neutral as water. I don't even think it is possible.)
As such, the improvement seen when they start drinking coffee could simply be a placebo effect. Coffee making is a nice daily ritual that helps being grounded in the present, as do sents, tastes and the feeling of a warm beverage.
The study is also fairly low power, as you have 62 people in four groups: coffee drinker with caffeine, coffee drinker with decaffeinated, non-coffee drinker with caffeine, non-coffee drinker with decaffeinated.
(Again, a big problem in many human studies is that it is very hard to recruit enough people, both for financial and organization reasons, so don't read this as a knock against the research team).
"J.F.C. [the professor in question] has been an invited speaker at conferences organised by Bromotech, Yakult and Nestle and has received research funding from Nutricia, DuPont/IFF, and Nestle. G.C. has received honoraria from Janssen, Probi, Apsen, and Ingelheim Boehringer as an invited speaker; is in receipt of research funding from Pharmavite, Fonterra, Reckitt, Nestle and Tate and Lyle; and has been paid for consultancy work by Yakult, Zentiva, Bayer Healthcare and Heel Pharmaceuticals. ES has received honorarium from Janssen Sciences Ireland UC. ES also received honorarium from MyNutriWeb for an event that was sponsored by Yakult. This support neither influenced nor constrained the contents of this manuscript. The remaining authors declare no competing interests."
I feel these disclaimers should be posted under every post about nutritional research that's linked on here. Not saying it proves anything in favour or not, but it's good to know who's getting paid to say what.
Any mood or depression study without a control group is, unfortunately, useless.
There is an interesting effect in mood related studies where every group usually improves on average, even if they receive only placebo. The real measure of any depression study is therefore the improvement above and beyond the control group.
The effect is so predictable that it has become an easy way to produce studies showing positive effects from something: All you have to do is track some group of people and then give ALL of them your supplement, and their scores will improve. It makes great headlines because most people don’t know you could have given them sugar pills and the scores would also improve.
EDIT: As another commenter pointed out, this person has an unusual long list of financial affiliations with companies that produce drink products, too. This study should probably be ignored
>The study also found differences in gut bacteria between coffee drinkers and non-coffee drinkers, including increases in species such as Eggertella sp and Cryptobacterium curtum, which are thought to play roles in gut function and metabolism.
>Cognitive effects varied depending on coffee type: decaffeinated coffee was associated with improvements in learning and memory, while caffeinated coffee was linked to reduced anxiety, improved vigilance and attention, as well as a reduced risk of inflammation.
Is this real, or is this a green jelly bean - https://xkcd.com/882/. Since most Americans (likely including you, though in some countries tea is more popular) are addicted to coffee they like to boost anything that makes their addiction seem like a good thing.
I love coffee, I take 2 to 3 every day (Italian espresso, so very short, little total caffeine), however for some reason taking the decaffeinated one in the evening interferes with my sleep in a similar way than the caffeinated one. Any hint?
I've never been a fan of coffee, but I liked drinking it, but more out of habit than desire, and always at work (rarely at home). Years ago I started to notice terrible headaches on the weekends, and only after a long time did I manage to understand that coffee withdrawal was the cause. For me the conclusion was obvious: I will no longer take something that affects my body at this level. I have the same problem with Coke/Pepsi, I stopped taking it too.
Fun fact: on the same day I noticed and stopped taking it coffee, 5 days later I had terrible muscle pain in my lower back (I could hardly sleep). 2 days later I had no more pain. I researched later and saw that this type of pain could also be caused as an effect of caffeine withdrawal.
13 comments
[ 1.6 ms ] story [ 52.0 ms ] threadAnd is the effect chemical, or there's also something about the ritual?
Has anyone compared groups that either drank coffee or took the same quantity in pills?
So it could easily just be cessation of withdrawal symptoms.
As such, the improvement seen when they start drinking coffee could simply be a placebo effect. Coffee making is a nice daily ritual that helps being grounded in the present, as do sents, tastes and the feeling of a warm beverage.
The study is also fairly low power, as you have 62 people in four groups: coffee drinker with caffeine, coffee drinker with decaffeinated, non-coffee drinker with caffeine, non-coffee drinker with decaffeinated.
(Again, a big problem in many human studies is that it is very hard to recruit enough people, both for financial and organization reasons, so don't read this as a knock against the research team).
I feel these disclaimers should be posted under every post about nutritional research that's linked on here. Not saying it proves anything in favour or not, but it's good to know who's getting paid to say what.
There is an interesting effect in mood related studies where every group usually improves on average, even if they receive only placebo. The real measure of any depression study is therefore the improvement above and beyond the control group.
The effect is so predictable that it has become an easy way to produce studies showing positive effects from something: All you have to do is track some group of people and then give ALL of them your supplement, and their scores will improve. It makes great headlines because most people don’t know you could have given them sugar pills and the scores would also improve.
EDIT: As another commenter pointed out, this person has an unusual long list of financial affiliations with companies that produce drink products, too. This study should probably be ignored
>The study also found differences in gut bacteria between coffee drinkers and non-coffee drinkers, including increases in species such as Eggertella sp and Cryptobacterium curtum, which are thought to play roles in gut function and metabolism.
>Cognitive effects varied depending on coffee type: decaffeinated coffee was associated with improvements in learning and memory, while caffeinated coffee was linked to reduced anxiety, improved vigilance and attention, as well as a reduced risk of inflammation.
The actual journal article has a lot more information, the clickbait headline doesn't really do it justice https://www.nature.com/articles/s41467-026-71264-8
This is a terrible sentence. As I understand it, you can't "reintroduce" coffee to non-coffee drinkers.
Fun fact: on the same day I noticed and stopped taking it coffee, 5 days later I had terrible muscle pain in my lower back (I could hardly sleep). 2 days later I had no more pain. I researched later and saw that this type of pain could also be caused as an effect of caffeine withdrawal.