15 ms·

Health Effects of Coffee

163 points by snikeris 6y ago

madarcho 6y ago
Interesting to me, that this is the first time I am hearing of lowered disease risk from regular coffee, which the study points out "has been confirmed in prospective cohort studies in many regions of the world". The way I understood it, the study aims to correlate benefits with the "plant" contents of coffee. What would be interesting to me is to see more about the effect of the roast. The study touches on it in a couple of points ("Phenolic Phytochemicals in Coffee May Account for Health Effects" where a darker roast produces more phenolic components), but I could do with something more specifically targeting the roast differences.
lowmemcpu 6y ago
> Habitual coffee consumption ranges from about 1 to more than 5 cups per day, which indicates that the daily dose is defined by something other than genetic reasons. One curious question I've always struggled with is, what is a "true" cup of coffee? I've often seen people say a "coffee" cup is 6 oz, but then I'm confused by this: 1 US cup = 8 oz 1 Imperial (British) = 10 oz 1 Australian cup = 8.45 oz
- hprotagonist 6y ago
  “coffee cup” is a semi-standard unit just like the ones you listed are. And yes, it’s about 6 fluid ounces, and no, nobody in the real world means “i drank 6 fluid ounces of coffee” when they say “i had a cup of coffee”. Overloading is fun!
  - varnisher 6y ago
    Instead of measuring coffee you could measure caffeine content, but a lot of effects may be in non-caffeine ingredients. Still, it's a first step.
    - lowmemcpu 6y ago
      That's what led me down this path. Searching the internet for "how much caffeine is in a cup of coffee" leads to the question of "what is a cup?", "how did you brew it?", "what kind of grounds did you use?".
      - hprotagonist 6y ago
        the real world is very nonlinear.
    - hprotagonist 6y ago
      “total dissolved solids” is a more comprehensive measure of coffee strength for the entourage effects reason.
- jcims 6y ago
  I think the cup count is useful from the habit standpoint, but the study should probably also include style of coffee or caffeine content. If I drink brewed coffee I’m on a steady flow for the day, sometimes making a second pot in the afternoon. I bought an espresso machine about a year ago, and one Americano in the morning pretty much sets me up for the whole day.
- dcolkitt 6y ago
  I've been confused by this for a while as well. The answer seems to be there's not such thing as a "true" cup of coffee. It pretty much just means whatever the respondent considers a cup. (In contrast to studies on alcohol consumption, where researchers have standardized units. And even on surveys will make sure to clarify with respondents so they get responses in normalized units.)
  - jschwartzi 6y ago
    There's an ISO standard for how to brew tea for laboratory comparison: https://en.wikipedia.org/wiki/ISO_3103 https://en.wikipedia.org/wiki/ISO_3103 Also here are all the ISO standards for coffee: https://www.iso.org/committee/47950/x/catalogue/p/1/u/0/w/0/d/0 https://www.iso.org/committee/47950/x/catalogue/p/1/u/0/w/0/... They don't yet have any brewing standards but a lot of what they seem to do is by nose with green or roasted ground coffee.
- paulcole 6y ago
  Many commercial coffee makers use 5 ounces when calculating the number of cups they serve. Scroll down to the comparison chart and look at the carafe sizes: https://www.bedbathandbeyond.com/store/product/ninja-reg-10-cup-stainless-steel-specialty-coffee-maker/5372531?keyword=10-cup-coffee-makers https://www.bedbathandbeyond.com/store/product/ninja-reg-10-...
- AnonC 6y ago
  What’s even more confusing, I think, is that even if someone defines one cup as a specific volume, approximately how much of a specific kind of coffee grounds or a specific instant coffee have to go into it? There can also be huge variations in the proportion of water used for black coffee, for example. I’m looking for some way to get the caffeine content of specific coffee types and brands, even if those are approximate.
- standardUser 6y ago
  Brewed coffee varies so much in potency, I'm not even sure how much the quantity of the liquid even matters. A shot of coffee that has been cold brewed with finely ground beans for 48 hours is dramatically more potent than a giant cup of coffee brewed quickly with less-fine grounds and hot water.
  - TheSpiceIsLife 6y ago
    From the Wikipedia article: Caffeine is moderately soluble in water at room temperature (2 g/100 mL), but very soluble in boiling water (66 g/100 mL). Caffeine is 33 times more soluble in hot water! What matters more, then, is the concentration of coffee grounds to water, and how much of that water is left in the grounds.
    - gattilorenz 6y ago
      > Caffeine is 33 times more soluble in hot water! On the other hand, you "boil" your coffee for 2 minutes, not 2880 minutes (48h). But I'm no chemist, so you might still be right, despite the different orders of magnitude. Also, we're not factoring in the water/steam pressure. Anybody volunteers for extracting coffee with an espresso machine for 48h?
    - standardUser 6y ago
      This doesn't have to be academic. You can do an experiment at home. Brew a big cup of coffee with a drip machine and drink it. Note how you feel. Then, make a batch of cold brew and let it sit for 48 hours. Drink half as much of that as you did the hot brewed coffee, but pease do so slowly as some people become very uncomfortable with that amount of caffeine.
      - KMag 6y ago
        Yes, cold brewed coffee can have much more caffeine than you'd expect given the smoothness of the taste. Back when my brother managed a coffee shop, the first time I popped into his work and asked his recommendation, he didn't warn me of the caffeine content. I was well habituated to caffeine, but quickly drinking 12 or 16 oz. of cold-brewed coffee left me feeling a bit dizzy, to the point I hung around the shop for a bit to make sure I was fine to drive.
- smarx007 6y ago
  In Europe, paper cups are usually 250ml (8.8oz) [1]. I presume German authors of this paper would have a similar volume in mind. [1]: https://www.tingstad.com/se-en/foodservice/disposable-cups/paper-cups/paper-hot-cup-bioware-25-30185769 https://www.tingstad.com/se-en/foodservice/disposable-cups/p... as an example
- StevePerkins 6y ago
  When I brew a pot of coffee, I fill it with water just past the line that represents 2x the number of cups I want. If I expect to drink 2 cups of coffee, then I fill it just past the "4" line. If I'm making a pot for multiple people and want 4 cups, then I fill it just past the "8" line. I think this is pretty normal. To the point where we don't even consciously think about it. In practice, a "cup of coffee" represents two cups as measured by the manufacturers. The manufacturers say that 6 oz is a cup, but a standard American coffee cup is 12 oz. I don't know why we don't simply make those match up.
  - mumblemumble 6y ago
    > I don't know why we don't simply make those match up. There are already so many units called the "cup". If we do anything along those lines, perhaps we instead define a new unit, the 'mug', that is equal to exactly two US coffee cups (12 US ounces, 1.5 US cups, 1.44 UK cups, 2.4 lungos, 0.75 Starbuckses) of coffee. Related: https://xkcd.com/927/ https://xkcd.com/927/
- bqlou 6y ago
  Glad I learned to drink coffee the italian way : one expresso cup (20/40ml). Strong, fruited, less caffeine. Loving it every morning.
- catilac 6y ago
  The instructions I follow for my pourover requires 350 grams of water. Much more than 8oz. It drives me crazy, but it also tastes good! Though If I only poured until reaching the 8oz mark it's also quite nice. That said, there is a question of "full-extraction".
  - m3kw9 6y ago
    Usually the ratio is 1:16 for full extraction without bitterness @200f with grain size slightly larger than refined sugar. That’s to maximize taste, without regard for nutrients. The bitter compounds probably make no difference.
- hoorayimhelping 6y ago
  And for that matter, how does the brewing method of coffee play into the health benefits? If I brew really strong coffee, do I get concentrated antioxidants and plant goodness? If I brew weak coffee and drink a lot of it over a longer period does that help my body's uptake of it? Not that knowing these answers will really change my coffee drinking habits, as this seems like a ridiculous micro optimization, but it would be nice to know a bit more about the mechanism here.
  - mchristen 6y ago
    Not to mention that processing and roasting also changes the bean and the resulting coffee brewed from it.
- srg0 6y ago
  Measuring weight of the dry ground coffee describes the actual consumption better. The standard espresso quantity is 7 g of ground coffee per cup (25 ml).
- octagonal 6y ago
  Well, there does exist this standard by the Specialty Coffee Association specifically intended as a reference for testing: https://sca.coffee/research/coffee-standards https://sca.coffee/research/coffee-standards It suggests that the 'cupping vessel' be "between 7 and 9 fluid ounces (207 ml to 266 ml), with a top diameter of between 3 and 3.5 inches (76 - 89 mm)"
- fnbr 6y ago
  For me, I use 20g of coffee, ground to a 20 on a Baratza Virtuoso, with a 275mL of water in a French press, brewed with boiling water for 4 minutes. If you change any of these variables- grind size, water temperature/volume, amount of coffee, etc, you drastically change the caffeine content.
- karmakaze 6y ago
  It's already confusing enough before using another ambiguous unit. 1 us fl oz = 0.96076 * uk fl oz
FakespotCom 6y ago
FYI: "H.K. received fees for providing consultant services to Tchibo GmbH. K.K. and S.M. reported no conflicts of interest." One of the main authors was compensated by the largest coffee retailer in Germany.
- manojlds 6y ago
  Reminds me of the Coffee video made by Hasan Minaj https://youtu.be/6HsC3wsTxms https://youtu.be/6HsC3wsTxms
- gen220 6y ago
  Apparently, many such coffee studies are sponsored by firms with an interest in publicizing coffee's benefits. It doesn't mean the science necessarily isn't good. Although, consider the opportunity cost: we could instead be researching many other things that don't carry as high a cost as coffee (in terms of production labor, refining, and transportation), and may commute even greater benefits. Of course, we shouldn't expect big corporations to sponsor that kind of research, because it's not in their interest. It is decidedly in the interest of coffee conglomerates to demonstrate that coffee is good for society, because it justifies the great fiscal and human expenses they go to, to bring fresh coffee to your breakfast table. Not passing judgement either way, it's just an interesting lens to consider. There was a nice article in the new yorker a couple months ago on the subject of society's shifting moods towards coffee, and how it's materialized in the literature and science. https://www.newyorker.com/magazine/2020/04/27/the-war-on-coffee https://www.newyorker.com/magazine/2020/04/27/the-war-on-cof.... One of the reviewed books: https://www.amazon.com/Coffeeland-Mans-Empire-Making-Favorite/dp/1594206155 https://www.amazon.com/Coffeeland-Mans-Empire-Making-Favorit.... Edit: oh boy. I misread the parent comment. I thought they had declared a conflict of interest. Sorry. I didn't intend for my comment to read as a corporate-research apologia.
  - coldtea 6y ago
    >Apparently, many such coffee studies are sponsored by firms with an interest in publicizing coffee's benefits. It doesn't mean the science isn't good. Usually the science isn't good even with no conflicts of interest, with 80% or more of studies being non-reproducible BS full of errors and cherry-picking. Now consider the percentage when there's also conflict of interest...
brunoqc 6y ago
I'm surprised there's no problem because of the roasting process. It's kinda burning it. Isn't burnt stuff carcinogenic?
- hprotagonist 6y ago
  Coffee roast temperatures are about 350 degrees. do you worry about getting cancer from bread? Bread ovens are about 200F hotter.
  - brunoqc 6y ago
    but the coffee turns very dark in some roast and it generates a lot of smokes during the process.
    - msb 6y ago
      The smoke comes from the chaff of the bean and steam as the beans release moisture. The actual bean never gets hot enough to produce smoke. Unless you over roast, but then your coffee is undrinkable.
  - phildawes 6y ago
    350f sounds too low to me. First crack (beginning of a very light roast) is around 200c/392f. Most coffee is roasted quite a bit darker than that - e.g. 220c and above https://en.wikipedia.org/wiki/Coffee_roasting https://en.wikipedia.org/wiki/Coffee_roasting
  - cl0wnshoes 6y ago
    Coffee roaster here, at 350F the beans have turned yellow and barely started browning. 390F~ is around the point where most roasters would consider development of flavor to really take off (yeah yeah pre-development phase, I'm keeping it short) and beans will be done at various points after that depending on roast preference. The smoke that the roaster produces towards the end of roast is no joke, and some has to get on the beans, but I'd say it is minimal enough to not be an issue as there should be plenty of air flowing through the roaster at that point. If roasted improperly oils could seep out of the beans while in the roaster which burn as well and stick to the beans. I'd say that is more of an issue than the smoke or roasting too dark.
__s 6y ago
Did a search on claim "Coffee plays a dominant role in that regard because it is the major dietary source of phenolic acids and polyphenols in the developed world": https://www.healthline.com/health/polyphenols-foods https://www.healthline.com/health/polyphenols-foods Granted it's suggested to cook these a bit to maximize absorbtion because cell walls & things
eloff 6y ago
Normally I'm content to follow the data where it leads, but I opened this with trepidation lest it give me a reason not to enjoy my morning coffee. Fortunately it confirms my pre-existing biases. I find I can never just have one cup, so I make a 50% decaf mix and have 3-4 cups spaced out over as many hours. Not only does this give a smooth and constant hit of caffeine, but it suppresses my appetite as well and I easily power right through from 5:30 until midday lunch. These are by far the most productive hours of my day.
- ambivalents 6y ago
  I often do this too, but I'm starting to feel what might be the pains of a stomach ulcer. Has this bothered your stomach? I'm worried about what all that coffee is doing on my empty stomach.
  - dominotw 6y ago
    Yes this effects my stomach ulcer. Somedays its good, somedays it fine.
    - TheSpiceIsLife 6y ago
      You say that like you just live with a stomach ulcer? They can be fixed in almost all cases with diet and antibiotics.
      - dominotw 6y ago
        you are right. But i need to fix my smoking addiction :/ .
        TheSpiceIsLife 6y ago
        You don't have to quit. The goal is to smoker fewer cigarettes in any five year period. Given very few quitters remain non-smokers for five years, if you can smoke about the same number of cigarettes as a cyclical quitter would in five years, you're as good. So, I advocate for the use of multiple methods of nicotine intake. Wear patches / use gum / chewies, and if you feel like a cigarette, have one. Have ten! Rejoice! Just smoke fewer.
newfeatureok 6y ago
If coffee is healthy (like the article suggests) because of the "plants" wouldn't tea be even healthier?
zwieback 6y ago
Also, apparently coffee drinkers want coffee more than they actually like it: https://digest.bps.org.uk/2020/06/22/heavy-coffee-drinkers-want-coffee-a-lot-more-than-they-actually-like-it/ https://digest.bps.org.uk/2020/06/22/heavy-coffee-drinkers-w... Research method seems sketchy to my engineering mind.
- mumblemumble 6y ago
  That's more-or-less in line with my personal experience. I usually drink tea, because I like a hot beverage, but find that my quality of sleep and overall sense of wellbeing tends to suffer if I drink coffee. Even when I only drink it in the mornings. But I do still like (don't love, but like) coffee, and most cafes and restaurants in my part of the world can't make a decent cup of tea to save their lives, so I often just drink coffee when I'm traveling. And I find that, even after only a few days of drinking coffee, I will experience 2 or 3 days of cravings once I get back home and return to my regularly scheduled pot of dragonwell.
  - zwieback 6y ago
    That's me as well, I drink tea at home, coffee at restaurants. Luckily a lot of coffeeshops now make a decent cup of tea as well, especially here in the Northwest.
- karmakaze 6y ago
  I enjoy both coffee and tea. When out it's much easier to get good coffee. For a while, I quit caffeine and sought out the best decaf beans I could find in the city and it was well worth it. I still enjoy them whenever I pick some up. I don't always want/need the caffeine but do enjoy the flavour and routine. Made me wonder, who's the coffee lover? The one who doesn't change it or the one who consumes it even without the active ingredient?
Angostura 6y ago
I really like thye kind of articles that the NHS does on this https://www.nhs.uk/news/food-and-diet/drinking-3-4-cups-coffee-day-may-have-some-health-benefits/ https://www.nhs.uk/news/food-and-diet/drinking-3-4-cups-coff...
- baxtr 6y ago
  > Drinking 3-4 cups of coffee a day may have some health benefits :-)
makerofspoons 6y ago
Has there been a study that weighs benefits from studies of coffee consumption against the societal health impacts of coffee production? I mean we have coffee farmers developing kidney disease (https://pubmed.ncbi.nlm.nih.gov/24878647/ https://pubmed.ncbi.nlm.nih.gov/24878647/) and the environmental impact of its cultivation and shipping (https://www.sustainablebusinesstoolkit.com/environmental-impact-coffee-trade/ https://www.sustainablebusinesstoolkit.com/environmental-imp...). It's the second most tradeable commodity after oil but as it's largely unnecessary for society to function. I would doubt it would come ahead as a net positive for humanity.
- baxtr 6y ago
  Where would you start and where would you end the analysis? What about for example the endless number of families that rely on coffee as income in developing countries?
  - makerofspoons 6y ago
    One could start by analyzing if the economic benefit of growing it and the healthcare savings of consuming it actually outweigh the long-term damage of its production. My hypothesis is once you strip away subsidies that allow farmers to clear forest for cultivation and fuel subsidies for shipping it across the ocean or by plane the hidden costs start to add up.
- mint2 6y ago
  But for comparison of workers/environment it’s not accurate to simply consider the effects of coffee, we need to consider the effects of the alternate to coffee. For the case of drinking coffee it’s easier but still a bit tricky. For workers and the environment I think that gets very hard but we should be trying to quantify it anyway. In the absence of coffee, How are they earning a living? Admittedly coffee provides a meager living for the people doing the growing, but what replaces it and are they worse or better off. I honestly don’t have a good idea.
aj_g 6y ago
Has anybody here experimented with coffee substitutes (such as https://www.cookinglight.com/good-food-fast/mud-wtr-mushroom-coffee-review https://www.cookinglight.com/good-food-fast/mud-wtr-mushroom... )?
- makerofspoons 6y ago
  I'm a fan of Postum. Interested in trying this mushroom coffee though I'm concerned about the footprint of where they get all of their ingredients.
johnfn 6y ago
I have a pet theory for why coffee has such great benefits: A lot of my friends who are more anxious have had to stop drinking coffee because it exacerbated their anxiety to extreme degrees. On the other hand, people with less anxiety drink it and feel fine. So there’s selection bias at play, and correlative studies are just picking up the benefit of not being anxious.
- silverdrake11 6y ago
  Enough people are addicted to coffee so much so that even if they are anxious while drinking it they continue to do so.
  - anaxag0ras 6y ago
    I happen to be on that camp. Despite having anxiety I haven't been able to outright quite coffee. I also have mild hypothyroid so coffee helps to overcome fatigue. However, I have reduced to about 1-2 cups/day from about 4 cups/day.
- ghostbrainalpha 6y ago
  I 100% agree. *Note to anyone quitting caffeine for anxiety reasons, it takes about a month to notice the benefit. Another pet theory I have is that a confounding variable in these studies is often the amount of work someone has to do, and the type of work. Someone drinking 4+ cups of coffee likely has a reason to be that productive. Which may result in more intellectual stimulation, a higher income, and other differences that makes the two groups very different. I'd like to see studies where the same individual both drank 4+ cups of coffee everyday for 6 months, and then quit caffeine entirely for 6 months and measure the changes in health, and output collectively but on an individual basis.
  - dllthomas 6y ago
    > I'd like to see studies where the same individual both drank 4+ cups of coffee everyday for 6 months, and then quit caffeine entirely for 6 months Ow!
ipunchghosts 6y ago
Is this a reputable paper? I am an academic and quit reviewing for MDPI 2 years ago because the quality of the initial submissions was so low.
OliverJones 6y ago
This is a complex scientific way of saying "coffee is a vegetable." Let's hope politicians with influence over school lunch menus don't misuse this result.
winrid 6y ago
Coffee/caffiene is only really useful to me when I have to do something I hate. Otherwise I'm more productive without the crash.
- techsin101 6y ago
  Finally someone who feels like me. I drink like once every two weeks. But only when I'm too exhausted and needed to do something yesterday. I don't like feeling weird as I do when after 3-4 hours of coffee like I'm having a high blood pressure or feel consciousness changing.
  - winrid 6y ago
    Ha, well, hello. Feeling the elevated heart rate while being tired and not able to take a nap indeed sucks. I get why people just start drinking 3-5 cups a day.
rantwasp 6y ago
for what is worth this has been known for a while (lookup Stanford medicine study). what’s interesting is that 4-5 cups per day is better than 1-2. also there is speculation that it’s not the caffeine but other things in coffee that have beneficial effects. i also suspect that large coffee consumption is better if you compare people that don’t get enough sleep (as someone that does not drink coffee will have a better quality of sleep - unless you drink 5 cups in the morning)
nsl73 6y ago
The abstract says that the majority of the benefits of coffee probably comes from phenolic phytochemicals. This implies you can receive all of the same health benefits like lower risks type 2 diabetes by eating other vegetables. Is the western diet really so weak that coffee is a major source of our vegetable intake?
- ekianjo 6y ago
  You do not find phenolic compounds in every vegetable.
- gridlockd 6y ago
  If people generally liked to eat vegetables, it would not need so much propaganda. I think the evidence that vegetables are all that healthy is not that great and the statistical effects are not large. Phytochemicals may be hormetic stressors, or they may just be stressors most bodies can deal with, but do not actually benefit from. Antioxidants in particular seem to not live up to expectations.
barrenko 6y ago
I view coffee as absolute evil, but necessity for any kind of office type work.
- iso8859-1 6y ago
  Why is it necessary? Do you fall asleep without coffee? Or do you just not feel productive without it?
  - barrenko 6y ago
    I just have trouble starting intellectual tasks without coffee, probably psychological or something.
notdang 6y ago
Anyone drinks coffee because they like it? Every time a coffee related subject comes up on HN, it seem that the majority is drinking it like a drug. Aren't there people that drink it because they like it? I like coffee. I don't drink it for waking up. Coffee is also my hobby. I search for good green beans, I roast it, I heavily invest in good equipment (grinders and espresso machines) and always chasing the elusive perfect shot of espresso. It kind of makes me sad that the majority of the people view it as a drug and consume it as a drug.
- Drakim 6y ago
  Indeed, there is something magical about a warm cup of dark coffee for me to sip while thinking over some problem. The way it's warm in my hands, the lingering somewhat bitter aftertaste, and the smell and aroma from the cup.
- bloodorange 6y ago
  I absolutely love coffee and if I could get the same taste without caffeine, that would be a dream for I can then drink as much as I want! I love the taste and the aroma. Good luck with your hunt for the perfect espresso! There is no other feeling like capturing the essence of those beans into a shot of espresso.
- mips_avatar 6y ago
  Just got my first espresso machine during WFH. It's a great hobby, I'm so happy every morning.
- phonypc 6y ago
  I imagine everyone who drinks coffee does so because they like it... else they wouldn't drink it. Some enjoy the flavor of straight coffee more than others, sure. I don't really understand how getting into coffee as a hobby makes it any less of a drug. You're still consuming caffeine. There's just as much of a hobby scene around marijuana; hobbyists are still consuming THC.
- carno 6y ago
  I love the flavor of black coffee. TBH I enjoy the flavor and the ritual of coffee making much much more than the caffeine kick (which is nice too). I'd actually drink more than one coffee cup a day if it weren't for the side effects. No, decaf is a sin.
shock 6y ago
It looks like CYP1A2 gene polymorphisms correlate with increased risk of non-fatal miocardial infarction: https://pubmed.ncbi.nlm.nih.gov/16522833/ https://pubmed.ncbi.nlm.nih.gov/16522833/.
sharkfinsoupmix 6y ago
I've always wondered about caffeine, whether in coffee or other products: does its potential neuroprotective and vigilance-promoting effects outweigh its potential diuretic, hypertensive, tachycardic, arrhythmic, and anticholinergic effects in both slow and fast caffeine metabolizers?
monkeycantype 6y ago
I didn't start drinking coffee until my late thirties, and feel as if I have had too different lives before and after. My life with coffee is happier, successful, productive, contented. If i had objective data, I think you would see it was more regularly patterned with respect to sleep, work, exercise. I think for me it was a little nudge across a transition threshold. I doubt coffee is bringing a huge health benefit on its own, and I reject the 'anyone can make it if they try attitude', but as a smart enough, healthy enough, lucky enough person in a wealthy country, my fate was very much bounded by my own lack of consistent organised disciplined effort. A little bit of coffee nudged my behaviour in a direction that has made me happier, and perhaps ultimately healthier.
znpy 6y ago
i wonder how coffee compares to tea in that sense.
liquidify 6y ago
I can't drink coffee because I have a nickle allergy and it makes my skin on my fingers get bumps all over them.
kgin 6y ago
It’s amazing how much people want coffee to be bad for you. That’s been a constant for at least hundreds of years.
a0-prw 6y ago
Reading the comments I've noticed a lot of people talking about addiction... I have for years had the habit of starting the day with 3 to 4 cups of strong coffee, either plain or with cream. I was pretty sure I was "addicted". Until the time, after about 2 weeks, when I noticed that the new brand I had quickly grabbed and happily consumed every day for 2 weeks was decaf. What you tell yourself is far more important and stronger than "addiction".

163 points by snikeris 6y ago

Interesting to me, that this is the first time I am hearing of lowered disease risk from regular coffee, which the study points out "has been confirmed in prospective cohort studies in many regions of the world". The way I understood it, the study aims to correlate benefits with the "plant" contents of coffee. What would be interesting to me is to see more about the effect of the roast. The study touches on it in a couple of points ("Phenolic Phytochemicals in Coffee May Account for Health Effects" where a darker roast produces more phenolic components), but I could do with something more specifically targeting the roast differences.

lowmemcpu 6y ago

> Habitual coffee consumption ranges from about 1 to more than 5 cups per day, which indicates that the daily dose is defined by something other than genetic reasons. One curious question I've always struggled with is, what is a "true" cup of coffee? I've often seen people say a "coffee" cup is 6 oz, but then I'm confused by this: 1 US cup = 8 oz 1 Imperial (British) = 10 oz 1 Australian cup = 8.45 oz

hprotagonist 6y ago
“coffee cup” is a semi-standard unit just like the ones you listed are. And yes, it’s about 6 fluid ounces, and no, nobody in the real world means “i drank 6 fluid ounces of coffee” when they say “i had a cup of coffee”. Overloading is fun!
- varnisher 6y ago
  Instead of measuring coffee you could measure caffeine content, but a lot of effects may be in non-caffeine ingredients. Still, it's a first step.
  - lowmemcpu 6y ago
    That's what led me down this path. Searching the internet for "how much caffeine is in a cup of coffee" leads to the question of "what is a cup?", "how did you brew it?", "what kind of grounds did you use?".
    - hprotagonist 6y ago
      the real world is very nonlinear.
  - hprotagonist 6y ago
    “total dissolved solids” is a more comprehensive measure of coffee strength for the entourage effects reason.
jcims 6y ago
I think the cup count is useful from the habit standpoint, but the study should probably also include style of coffee or caffeine content. If I drink brewed coffee I’m on a steady flow for the day, sometimes making a second pot in the afternoon. I bought an espresso machine about a year ago, and one Americano in the morning pretty much sets me up for the whole day.
dcolkitt 6y ago
I've been confused by this for a while as well. The answer seems to be there's not such thing as a "true" cup of coffee. It pretty much just means whatever the respondent considers a cup. (In contrast to studies on alcohol consumption, where researchers have standardized units. And even on surveys will make sure to clarify with respondents so they get responses in normalized units.)
- jschwartzi 6y ago
  There's an ISO standard for how to brew tea for laboratory comparison: https://en.wikipedia.org/wiki/ISO_3103 https://en.wikipedia.org/wiki/ISO_3103 Also here are all the ISO standards for coffee: https://www.iso.org/committee/47950/x/catalogue/p/1/u/0/w/0/d/0 https://www.iso.org/committee/47950/x/catalogue/p/1/u/0/w/0/... They don't yet have any brewing standards but a lot of what they seem to do is by nose with green or roasted ground coffee.
paulcole 6y ago
Many commercial coffee makers use 5 ounces when calculating the number of cups they serve. Scroll down to the comparison chart and look at the carafe sizes: https://www.bedbathandbeyond.com/store/product/ninja-reg-10-cup-stainless-steel-specialty-coffee-maker/5372531?keyword=10-cup-coffee-makers https://www.bedbathandbeyond.com/store/product/ninja-reg-10-...
AnonC 6y ago
What’s even more confusing, I think, is that even if someone defines one cup as a specific volume, approximately how much of a specific kind of coffee grounds or a specific instant coffee have to go into it? There can also be huge variations in the proportion of water used for black coffee, for example. I’m looking for some way to get the caffeine content of specific coffee types and brands, even if those are approximate.
standardUser 6y ago
Brewed coffee varies so much in potency, I'm not even sure how much the quantity of the liquid even matters. A shot of coffee that has been cold brewed with finely ground beans for 48 hours is dramatically more potent than a giant cup of coffee brewed quickly with less-fine grounds and hot water.
- TheSpiceIsLife 6y ago
  From the Wikipedia article: Caffeine is moderately soluble in water at room temperature (2 g/100 mL), but very soluble in boiling water (66 g/100 mL). Caffeine is 33 times more soluble in hot water! What matters more, then, is the concentration of coffee grounds to water, and how much of that water is left in the grounds.
  - gattilorenz 6y ago
    > Caffeine is 33 times more soluble in hot water! On the other hand, you "boil" your coffee for 2 minutes, not 2880 minutes (48h). But I'm no chemist, so you might still be right, despite the different orders of magnitude. Also, we're not factoring in the water/steam pressure. Anybody volunteers for extracting coffee with an espresso machine for 48h?
  - standardUser 6y ago
    This doesn't have to be academic. You can do an experiment at home. Brew a big cup of coffee with a drip machine and drink it. Note how you feel. Then, make a batch of cold brew and let it sit for 48 hours. Drink half as much of that as you did the hot brewed coffee, but pease do so slowly as some people become very uncomfortable with that amount of caffeine.
    - KMag 6y ago
      Yes, cold brewed coffee can have much more caffeine than you'd expect given the smoothness of the taste. Back when my brother managed a coffee shop, the first time I popped into his work and asked his recommendation, he didn't warn me of the caffeine content. I was well habituated to caffeine, but quickly drinking 12 or 16 oz. of cold-brewed coffee left me feeling a bit dizzy, to the point I hung around the shop for a bit to make sure I was fine to drive.
smarx007 6y ago
In Europe, paper cups are usually 250ml (8.8oz) [1]. I presume German authors of this paper would have a similar volume in mind. [1]: https://www.tingstad.com/se-en/foodservice/disposable-cups/paper-cups/paper-hot-cup-bioware-25-30185769 https://www.tingstad.com/se-en/foodservice/disposable-cups/p... as an example
StevePerkins 6y ago
When I brew a pot of coffee, I fill it with water just past the line that represents 2x the number of cups I want. If I expect to drink 2 cups of coffee, then I fill it just past the "4" line. If I'm making a pot for multiple people and want 4 cups, then I fill it just past the "8" line. I think this is pretty normal. To the point where we don't even consciously think about it. In practice, a "cup of coffee" represents two cups as measured by the manufacturers. The manufacturers say that 6 oz is a cup, but a standard American coffee cup is 12 oz. I don't know why we don't simply make those match up.
- mumblemumble 6y ago
  > I don't know why we don't simply make those match up. There are already so many units called the "cup". If we do anything along those lines, perhaps we instead define a new unit, the 'mug', that is equal to exactly two US coffee cups (12 US ounces, 1.5 US cups, 1.44 UK cups, 2.4 lungos, 0.75 Starbuckses) of coffee. Related: https://xkcd.com/927/ https://xkcd.com/927/
bqlou 6y ago
Glad I learned to drink coffee the italian way : one expresso cup (20/40ml). Strong, fruited, less caffeine. Loving it every morning.
catilac 6y ago
The instructions I follow for my pourover requires 350 grams of water. Much more than 8oz. It drives me crazy, but it also tastes good! Though If I only poured until reaching the 8oz mark it's also quite nice. That said, there is a question of "full-extraction".
- m3kw9 6y ago
  Usually the ratio is 1:16 for full extraction without bitterness @200f with grain size slightly larger than refined sugar. That’s to maximize taste, without regard for nutrients. The bitter compounds probably make no difference.
hoorayimhelping 6y ago
And for that matter, how does the brewing method of coffee play into the health benefits? If I brew really strong coffee, do I get concentrated antioxidants and plant goodness? If I brew weak coffee and drink a lot of it over a longer period does that help my body's uptake of it? Not that knowing these answers will really change my coffee drinking habits, as this seems like a ridiculous micro optimization, but it would be nice to know a bit more about the mechanism here.
- mchristen 6y ago
  Not to mention that processing and roasting also changes the bean and the resulting coffee brewed from it.
srg0 6y ago
Measuring weight of the dry ground coffee describes the actual consumption better. The standard espresso quantity is 7 g of ground coffee per cup (25 ml).
octagonal 6y ago
Well, there does exist this standard by the Specialty Coffee Association specifically intended as a reference for testing: https://sca.coffee/research/coffee-standards https://sca.coffee/research/coffee-standards It suggests that the 'cupping vessel' be "between 7 and 9 fluid ounces (207 ml to 266 ml), with a top diameter of between 3 and 3.5 inches (76 - 89 mm)"
fnbr 6y ago
For me, I use 20g of coffee, ground to a 20 on a Baratza Virtuoso, with a 275mL of water in a French press, brewed with boiling water for 4 minutes. If you change any of these variables- grind size, water temperature/volume, amount of coffee, etc, you drastically change the caffeine content.
karmakaze 6y ago
It's already confusing enough before using another ambiguous unit. 1 us fl oz = 0.96076 * uk fl oz

FakespotCom 6y ago

FYI: "H.K. received fees for providing consultant services to Tchibo GmbH. K.K. and S.M. reported no conflicts of interest." One of the main authors was compensated by the largest coffee retailer in Germany.

manojlds 6y ago
Reminds me of the Coffee video made by Hasan Minaj https://youtu.be/6HsC3wsTxms https://youtu.be/6HsC3wsTxms
gen220 6y ago
Apparently, many such coffee studies are sponsored by firms with an interest in publicizing coffee's benefits. It doesn't mean the science necessarily isn't good. Although, consider the opportunity cost: we could instead be researching many other things that don't carry as high a cost as coffee (in terms of production labor, refining, and transportation), and may commute even greater benefits. Of course, we shouldn't expect big corporations to sponsor that kind of research, because it's not in their interest. It is decidedly in the interest of coffee conglomerates to demonstrate that coffee is good for society, because it justifies the great fiscal and human expenses they go to, to bring fresh coffee to your breakfast table. Not passing judgement either way, it's just an interesting lens to consider. There was a nice article in the new yorker a couple months ago on the subject of society's shifting moods towards coffee, and how it's materialized in the literature and science. https://www.newyorker.com/magazine/2020/04/27/the-war-on-coffee https://www.newyorker.com/magazine/2020/04/27/the-war-on-cof.... One of the reviewed books: https://www.amazon.com/Coffeeland-Mans-Empire-Making-Favorite/dp/1594206155 https://www.amazon.com/Coffeeland-Mans-Empire-Making-Favorit.... Edit: oh boy. I misread the parent comment. I thought they had declared a conflict of interest. Sorry. I didn't intend for my comment to read as a corporate-research apologia.
- coldtea 6y ago
  >Apparently, many such coffee studies are sponsored by firms with an interest in publicizing coffee's benefits. It doesn't mean the science isn't good. Usually the science isn't good even with no conflicts of interest, with 80% or more of studies being non-reproducible BS full of errors and cherry-picking. Now consider the percentage when there's also conflict of interest...

brunoqc 6y ago

I'm surprised there's no problem because of the roasting process. It's kinda burning it. Isn't burnt stuff carcinogenic?

hprotagonist 6y ago
Coffee roast temperatures are about 350 degrees. do you worry about getting cancer from bread? Bread ovens are about 200F hotter.
- brunoqc 6y ago
  but the coffee turns very dark in some roast and it generates a lot of smokes during the process.
  - msb 6y ago
    The smoke comes from the chaff of the bean and steam as the beans release moisture. The actual bean never gets hot enough to produce smoke. Unless you over roast, but then your coffee is undrinkable.
- phildawes 6y ago
  350f sounds too low to me. First crack (beginning of a very light roast) is around 200c/392f. Most coffee is roasted quite a bit darker than that - e.g. 220c and above https://en.wikipedia.org/wiki/Coffee_roasting https://en.wikipedia.org/wiki/Coffee_roasting
- cl0wnshoes 6y ago
  Coffee roaster here, at 350F the beans have turned yellow and barely started browning. 390F~ is around the point where most roasters would consider development of flavor to really take off (yeah yeah pre-development phase, I'm keeping it short) and beans will be done at various points after that depending on roast preference. The smoke that the roaster produces towards the end of roast is no joke, and some has to get on the beans, but I'd say it is minimal enough to not be an issue as there should be plenty of air flowing through the roaster at that point. If roasted improperly oils could seep out of the beans while in the roaster which burn as well and stick to the beans. I'd say that is more of an issue than the smoke or roasting too dark.

__s 6y ago

Did a search on claim "Coffee plays a dominant role in that regard because it is the major dietary source of phenolic acids and polyphenols in the developed world": https://www.healthline.com/health/polyphenols-foods https://www.healthline.com/health/polyphenols-foods Granted it's suggested to cook these a bit to maximize absorbtion because cell walls & things

eloff 6y ago

Normally I'm content to follow the data where it leads, but I opened this with trepidation lest it give me a reason not to enjoy my morning coffee. Fortunately it confirms my pre-existing biases. I find I can never just have one cup, so I make a 50% decaf mix and have 3-4 cups spaced out over as many hours. Not only does this give a smooth and constant hit of caffeine, but it suppresses my appetite as well and I easily power right through from 5:30 until midday lunch. These are by far the most productive hours of my day.

ambivalents 6y ago
I often do this too, but I'm starting to feel what might be the pains of a stomach ulcer. Has this bothered your stomach? I'm worried about what all that coffee is doing on my empty stomach.
- dominotw 6y ago
  Yes this effects my stomach ulcer. Somedays its good, somedays it fine.
  - TheSpiceIsLife 6y ago
    You say that like you just live with a stomach ulcer? They can be fixed in almost all cases with diet and antibiotics.
    - dominotw 6y ago
      you are right. But i need to fix my smoking addiction :/ .
      - TheSpiceIsLife 6y ago
        You don't have to quit. The goal is to smoker fewer cigarettes in any five year period. Given very few quitters remain non-smokers for five years, if you can smoke about the same number of cigarettes as a cyclical quitter would in five years, you're as good. So, I advocate for the use of multiple methods of nicotine intake. Wear patches / use gum / chewies, and if you feel like a cigarette, have one. Have ten! Rejoice! Just smoke fewer.

newfeatureok 6y ago

If coffee is healthy (like the article suggests) because of the "plants" wouldn't tea be even healthier?

zwieback 6y ago

Also, apparently coffee drinkers want coffee more than they actually like it: https://digest.bps.org.uk/2020/06/22/heavy-coffee-drinkers-want-coffee-a-lot-more-than-they-actually-like-it/ https://digest.bps.org.uk/2020/06/22/heavy-coffee-drinkers-w... Research method seems sketchy to my engineering mind.

mumblemumble 6y ago
That's more-or-less in line with my personal experience. I usually drink tea, because I like a hot beverage, but find that my quality of sleep and overall sense of wellbeing tends to suffer if I drink coffee. Even when I only drink it in the mornings. But I do still like (don't love, but like) coffee, and most cafes and restaurants in my part of the world can't make a decent cup of tea to save their lives, so I often just drink coffee when I'm traveling. And I find that, even after only a few days of drinking coffee, I will experience 2 or 3 days of cravings once I get back home and return to my regularly scheduled pot of dragonwell.
- zwieback 6y ago
  That's me as well, I drink tea at home, coffee at restaurants. Luckily a lot of coffeeshops now make a decent cup of tea as well, especially here in the Northwest.
karmakaze 6y ago
I enjoy both coffee and tea. When out it's much easier to get good coffee. For a while, I quit caffeine and sought out the best decaf beans I could find in the city and it was well worth it. I still enjoy them whenever I pick some up. I don't always want/need the caffeine but do enjoy the flavour and routine. Made me wonder, who's the coffee lover? The one who doesn't change it or the one who consumes it even without the active ingredient?

Angostura 6y ago

I really like thye kind of articles that the NHS does on this https://www.nhs.uk/news/food-and-diet/drinking-3-4-cups-coffee-day-may-have-some-health-benefits/ https://www.nhs.uk/news/food-and-diet/drinking-3-4-cups-coff...

baxtr 6y ago
> Drinking 3-4 cups of coffee a day may have some health benefits :-)

makerofspoons 6y ago

Has there been a study that weighs benefits from studies of coffee consumption against the societal health impacts of coffee production? I mean we have coffee farmers developing kidney disease (https://pubmed.ncbi.nlm.nih.gov/24878647/ https://pubmed.ncbi.nlm.nih.gov/24878647/) and the environmental impact of its cultivation and shipping (https://www.sustainablebusinesstoolkit.com/environmental-impact-coffee-trade/ https://www.sustainablebusinesstoolkit.com/environmental-imp...). It's the second most tradeable commodity after oil but as it's largely unnecessary for society to function. I would doubt it would come ahead as a net positive for humanity.

baxtr 6y ago
Where would you start and where would you end the analysis? What about for example the endless number of families that rely on coffee as income in developing countries?
- makerofspoons 6y ago
  One could start by analyzing if the economic benefit of growing it and the healthcare savings of consuming it actually outweigh the long-term damage of its production. My hypothesis is once you strip away subsidies that allow farmers to clear forest for cultivation and fuel subsidies for shipping it across the ocean or by plane the hidden costs start to add up.
mint2 6y ago
But for comparison of workers/environment it’s not accurate to simply consider the effects of coffee, we need to consider the effects of the alternate to coffee. For the case of drinking coffee it’s easier but still a bit tricky. For workers and the environment I think that gets very hard but we should be trying to quantify it anyway. In the absence of coffee, How are they earning a living? Admittedly coffee provides a meager living for the people doing the growing, but what replaces it and are they worse or better off. I honestly don’t have a good idea.

aj_g 6y ago

Has anybody here experimented with coffee substitutes (such as https://www.cookinglight.com/good-food-fast/mud-wtr-mushroom-coffee-review https://www.cookinglight.com/good-food-fast/mud-wtr-mushroom... )?

makerofspoons 6y ago
I'm a fan of Postum. Interested in trying this mushroom coffee though I'm concerned about the footprint of where they get all of their ingredients.

johnfn 6y ago

I have a pet theory for why coffee has such great benefits: A lot of my friends who are more anxious have had to stop drinking coffee because it exacerbated their anxiety to extreme degrees. On the other hand, people with less anxiety drink it and feel fine. So there’s selection bias at play, and correlative studies are just picking up the benefit of not being anxious.

silverdrake11 6y ago
Enough people are addicted to coffee so much so that even if they are anxious while drinking it they continue to do so.
- anaxag0ras 6y ago
  I happen to be on that camp. Despite having anxiety I haven't been able to outright quite coffee. I also have mild hypothyroid so coffee helps to overcome fatigue. However, I have reduced to about 1-2 cups/day from about 4 cups/day.
ghostbrainalpha 6y ago
I 100% agree. *Note to anyone quitting caffeine for anxiety reasons, it takes about a month to notice the benefit. Another pet theory I have is that a confounding variable in these studies is often the amount of work someone has to do, and the type of work. Someone drinking 4+ cups of coffee likely has a reason to be that productive. Which may result in more intellectual stimulation, a higher income, and other differences that makes the two groups very different. I'd like to see studies where the same individual both drank 4+ cups of coffee everyday for 6 months, and then quit caffeine entirely for 6 months and measure the changes in health, and output collectively but on an individual basis.
- dllthomas 6y ago
  > I'd like to see studies where the same individual both drank 4+ cups of coffee everyday for 6 months, and then quit caffeine entirely for 6 months Ow!

ipunchghosts 6y ago

Is this a reputable paper? I am an academic and quit reviewing for MDPI 2 years ago because the quality of the initial submissions was so low.

OliverJones 6y ago

This is a complex scientific way of saying "coffee is a vegetable." Let's hope politicians with influence over school lunch menus don't misuse this result.

winrid 6y ago

Coffee/caffiene is only really useful to me when I have to do something I hate. Otherwise I'm more productive without the crash.

techsin101 6y ago
Finally someone who feels like me. I drink like once every two weeks. But only when I'm too exhausted and needed to do something yesterday. I don't like feeling weird as I do when after 3-4 hours of coffee like I'm having a high blood pressure or feel consciousness changing.
- winrid 6y ago
  Ha, well, hello. Feeling the elevated heart rate while being tired and not able to take a nap indeed sucks. I get why people just start drinking 3-5 cups a day.

rantwasp 6y ago

for what is worth this has been known for a while (lookup Stanford medicine study). what’s interesting is that 4-5 cups per day is better than 1-2. also there is speculation that it’s not the caffeine but other things in coffee that have beneficial effects. i also suspect that large coffee consumption is better if you compare people that don’t get enough sleep (as someone that does not drink coffee will have a better quality of sleep - unless you drink 5 cups in the morning)

nsl73 6y ago

The abstract says that the majority of the benefits of coffee probably comes from phenolic phytochemicals. This implies you can receive all of the same health benefits like lower risks type 2 diabetes by eating other vegetables. Is the western diet really so weak that coffee is a major source of our vegetable intake?

ekianjo 6y ago
You do not find phenolic compounds in every vegetable.
gridlockd 6y ago
If people generally liked to eat vegetables, it would not need so much propaganda. I think the evidence that vegetables are all that healthy is not that great and the statistical effects are not large. Phytochemicals may be hormetic stressors, or they may just be stressors most bodies can deal with, but do not actually benefit from. Antioxidants in particular seem to not live up to expectations.

barrenko 6y ago

I view coffee as absolute evil, but necessity for any kind of office type work.

iso8859-1 6y ago
Why is it necessary? Do you fall asleep without coffee? Or do you just not feel productive without it?
- barrenko 6y ago
  I just have trouble starting intellectual tasks without coffee, probably psychological or something.

notdang 6y ago

Anyone drinks coffee because they like it? Every time a coffee related subject comes up on HN, it seem that the majority is drinking it like a drug. Aren't there people that drink it because they like it? I like coffee. I don't drink it for waking up. Coffee is also my hobby. I search for good green beans, I roast it, I heavily invest in good equipment (grinders and espresso machines) and always chasing the elusive perfect shot of espresso. It kind of makes me sad that the majority of the people view it as a drug and consume it as a drug.

Drakim 6y ago
Indeed, there is something magical about a warm cup of dark coffee for me to sip while thinking over some problem. The way it's warm in my hands, the lingering somewhat bitter aftertaste, and the smell and aroma from the cup.
bloodorange 6y ago
I absolutely love coffee and if I could get the same taste without caffeine, that would be a dream for I can then drink as much as I want! I love the taste and the aroma. Good luck with your hunt for the perfect espresso! There is no other feeling like capturing the essence of those beans into a shot of espresso.
mips_avatar 6y ago
Just got my first espresso machine during WFH. It's a great hobby, I'm so happy every morning.
phonypc 6y ago
I imagine everyone who drinks coffee does so because they like it... else they wouldn't drink it. Some enjoy the flavor of straight coffee more than others, sure. I don't really understand how getting into coffee as a hobby makes it any less of a drug. You're still consuming caffeine. There's just as much of a hobby scene around marijuana; hobbyists are still consuming THC.
carno 6y ago
I love the flavor of black coffee. TBH I enjoy the flavor and the ritual of coffee making much much more than the caffeine kick (which is nice too). I'd actually drink more than one coffee cup a day if it weren't for the side effects. No, decaf is a sin.

shock 6y ago

It looks like CYP1A2 gene polymorphisms correlate with increased risk of non-fatal miocardial infarction: https://pubmed.ncbi.nlm.nih.gov/16522833/ https://pubmed.ncbi.nlm.nih.gov/16522833/.

sharkfinsoupmix 6y ago

I've always wondered about caffeine, whether in coffee or other products: does its potential neuroprotective and vigilance-promoting effects outweigh its potential diuretic, hypertensive, tachycardic, arrhythmic, and anticholinergic effects in both slow and fast caffeine metabolizers?

monkeycantype 6y ago

I didn't start drinking coffee until my late thirties, and feel as if I have had too different lives before and after. My life with coffee is happier, successful, productive, contented. If i had objective data, I think you would see it was more regularly patterned with respect to sleep, work, exercise. I think for me it was a little nudge across a transition threshold. I doubt coffee is bringing a huge health benefit on its own, and I reject the 'anyone can make it if they try attitude', but as a smart enough, healthy enough, lucky enough person in a wealthy country, my fate was very much bounded by my own lack of consistent organised disciplined effort. A little bit of coffee nudged my behaviour in a direction that has made me happier, and perhaps ultimately healthier.

znpy 6y ago

i wonder how coffee compares to tea in that sense.

liquidify 6y ago

I can't drink coffee because I have a nickle allergy and it makes my skin on my fingers get bumps all over them.

kgin 6y ago

It’s amazing how much people want coffee to be bad for you. That’s been a constant for at least hundreds of years.

a0-prw 6y ago

Reading the comments I've noticed a lot of people talking about addiction... I have for years had the habit of starting the day with 3 to 4 cups of strong coffee, either plain or with cream. I was pretty sure I was "addicted". Until the time, after about 2 weeks, when I noticed that the new brand I had quickly grabbed and happily consumed every day for 2 weeks was decaf. What you tell yourself is far more important and stronger than "addiction".