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Drinking 3-4 Cups of Coffee Is “More Likely to Benefit Health Than to Harm It” (sciencedaily.com)
160 points by Exo_Tartarus on Nov 26, 2017 | hide | past | favorite | 152 comments

I'm going to go out on a limb here and state a theory I've been considering for a while that could explain these coffee health benefit results...

The liquids I and everyone else consumes can be placed in two classes: pure water and everything else.

When I'm not drinking pure water, my drink of choice is usually coffee, of which I drink about 3 cups a day.

Now let's think of the alternative non water drinks out there... Many of them are sodas which have obscenely high sugar levels, just like most drinks that aren't pure water.

Someone who doesn't drink coffee may have more of these sugar containing drinks when they're not drinking pure water, inundating their bodies with harmful amounts of sugar.

So the benefits we see from high levels of coffee consumption come not from the coffee itself but from a substitution effect of replacing unhealthy sugary drinks with coffee.

A good test for this would be to see if tea drinkers also experience health benefits similar to those seen in the study. If not then that may indicate that my theory is wrong.

Here's another theory. Coffee makes you move more. Moving is healthy. Think of how coffee gets people off their desks to get it and also because of the caffeine and the need to urinate after. Its unlike other drinks as people don't carry it in bottles, it requires more movement. Maybe the sedentary lifestyle is what's killing people.

I'd counter that. Coffee makes me sit down and intently focus unmoved; time speeds by.

Coke and Meth also make you move more ... not sure I'd call those health supplements.

Could have sworn i have seen old ads for meth as a diet pill...

It is the amount.

Probably right. I drink 2-3 espresso shots a day, one at home in the morning and one after lunch when I have to walk 10 minutes to get. Some people don't even bother to leave their desk or complain it's long walk.

I think you're correct. I'm also actually astonished how many people drink sugared/flavoured drinks (including "juice" and "milk") as a substitute for water and never question what effect this might be having on them. I would encourage everyone to stop drinking anything except water for 6 months just to see what happens.

I usually drink just tap water, and what I've noticed is that over time I will get sick and feel really dehydrated. I then buy myself a 1.5 liter mineral water from the store and feel much better. I wonder if the "tap water" that we drink is actually the "natural state of water", or if people aren't used to consuming water with a higher mineral content in nature.

Tap water doesn't necessarily have any more or less mineral content than bottled mineral water. The variation between mineral water brands and the variation between tap water sources (mostly: well water vs surface) is much larger than any difference between bottled and tap.

If you live in an area with hard tap water you're essentially drinking "mineral water" out of the tap.

Here's some data for ya:

Mineral Content of Tap Water in Major North American Cities: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1495189/table/t...

Mineral Content of Selected Commercially Available North American Bottled Waters: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1495189/table/t...

It depends where you live I think. Your tap water, if it's good, should normally contain a lot of minerals already. If you're drinking some kind of reverse-osmosis filtered water, then what you're saying makes total sense.

I lived in Cambodia for a while, where tap-water is a no go for drinking, and even though we avoided buying plastic bottles (plastic is a huge problem particularly in S.E. Asia) and instead stuck to larger tanks of filtered water, we had to make a point of always having some bottled mineral water in the mix. It was quickly noticeable when you hadn't had enough (extremely tired, drowsy, etc.)

If you want to get hydrated, you should drink water with approximately the same concentration of minerals as your body, especially if you lose a lot of water by sweating or sickness. Osmosis in your cells happens along the concentration gradient. Drinking water with too little concentration can cause them to swell, drinking water with too much can make them shrivel. Neither is good in the extreme.

Very interesting. I've felt this as well. Even bottled flat water, doesn't seem to hydrate me as well as a carbonated mineral water (e.g. Perrier or Pellegrino). I wonder if this is placebo or if there is some other meaningful effect happening.

From what I’ve read, they’ve controlled for variables like this. Pure water drinkers don’t see the same benefit.

But I’ll be honest, I haven’t looked into it too thouroghly.

But for people in general, just because they drink coffee doesn't mean they cannot also drink beverages with high sugar content or am I not getting your thought right?

The assumptions I'm making are that most people drink water and non water, and the non water they drink is not going to be more than 3 to 4 drinks (cups/bottles) per day, and that people drinking coffee are already filling their quota of non water drinks by drinking coffee so they don't drink sugary drinks.

The assumption is still that most people drink water during the day in addition to the coffee, and I'd think that is actually not the case. My experience is water is just an occasional drink during the day, not a primary drink.

That may be true, but wouldn't that not affect my argument?

The parent is assuming everyone acts like him, and I'm inclined to agree from personal anecdata.

What about all the people that add sugar to their coffee?

Most people who add sugar to their coffee use a couple of teaspoons, so probably less than 15 g of sugar. Now in e.g. a Coca Cola, there's 10.6 g of sugar in each 100ml. You'll probably drink at least 300-600ml of coke.

Drinking "Pure Water" wouldn't be advised, since it will leech minerals from your body.

> A good test for this would be to see if tea drinkers also experience health benefits similar to those seen in the study. If not then that may indicate that my theory is wrong.

Yes, or drinks with artificial sweeteners.

Counter theory: Higher coffee consumption might actually increase the craving for some sugary treat like donuts and banana bread, the classic companions to coffee.

I thought coffee’s actually an appetite suppressant than stimulant.

There's been studies to this, for example [1]

"Dando's previous research had already found that when you chemically block people's ability to taste sweet flavors, it makes them crave more sugar and seek out higher-calorie treats. Based on his collective research, we now know that drinking a caffeinated cup of coffee, which has the same blocking effect, makes people want cookies or cake more than they otherwise would."

Caffeine seems to blocks the adenosine receptors, which makes us feel less sleepy, but these same receptors also play a part in helping us taste sweet flavors. While doing this, it pushes us to find more sweet, sugary tastes. This might be a part of why when drinking coffee especially, which is also pungent and bitter in taste, opposed to sweet, might drive us toward these sugary treats.

Also I feel coffee depletes our energy levels very fast, making us feel more tired when the effect comes down, making hte body want to replenish those energies quickly, and high in sugar ingredients do that fast, with a price though.

It's interesting why tea and mate for example don't have this effect so clearly, maybe it has to do with the bitternes of coffee and the way it is roasted, not sure.

1: http://www.chicagotribune.com/lifestyles/health/ct-coffee-an...

A strong coffee (e.g. via a Moka pot) should send you to the bathroom too.

Would you have any sources on that?

I casually looked into that claim in the past and read that coffee is as strong a diuretic as pure water.

there's.... i believe there is enough anecdotal evidence to state with a reasonable confidence level that coffee makes you poop.

Yeah really no need to study this. There's "anecdotal" and then there's "this happens to 80% of people and we have cute euphemisms for when you excuse yourself" and that to me is as good as the most rigorous of studies. Now uhh, excuse me, back in a sec.

Chiming in for n+1. Can confirm: I enjoy my post-caffeine quiet time. :)

Hmmm, I smell an IG Nobel prize opportunity for an ambitious grad student who is not afraid to get his hands dirty.

What? I drink rather a lot of coffee and have never had that effect. I've never heard it from anyone else either. Is there any non-anecdotal evidence for this?

Do you primarily drink iced, cold brewed, or something like keurig?

Nope, just normal coffee. Sometimes made in a cafetiere, sometimes from the (rather good) machine at work, but I mostly make Greek or Turkish style these days. It's never given me a dose of the shits however its made though!

The caffeine relaxes the intestinal tract..

Caffeine is a stimulant. One of the things it stimulates are your colonic muscles which can induce peristalsis.

Perhaps they mean as a laxative rather than as a diuretic.

Yes, I believe so from the comments.

This is mentioned in the article, 2nd last paragraph.

That statement was ambiguous, I assumed it was referring to coffee drinks like mochas and lattes instead of additional snacks.

I'm sure those tea studies have been done, any industry would love to show their product is healthy.

What about sugar-free sodas?

In about 100 years, people will realize that this kind of research doesn't actually work.

Here's the problem: the human body is an immensely complex system, with millions of factors influencing its status and well-being. Untangling these factors correctly and producing an accurate and sophisticated statistical theory of the body would require a comparably large number of parameters - on the order of millions or more.

Unfortunately, modern medical science relies on low-N observational or clinical trials, with N on the order of hundreds or thousands. In this radically low-data regime it is impossible to justify the use of complex models. If you try to use a complex model, you will just get overfitting. You can use a simple model to avoid overfitting, but there's no reason to believe that a simple model will produce a good approximation of the underlying dynamics.

Happily, these kinds of studies aren't attempting to create a comprehensive statistical model of the human body, in any reasonable sense- they're just asking, "if we change X in modern human lifestyle, and leave every other factor within the range of typical variation, how does it change Y?" Thus, in almost every case, the millions of other factors influencing human wellbeing can be completely ignored for the purposes of the study, as long as they're reasonably well represented in the study population.

In terms of caffeine studies, yes- there are definitely thousands of other foods and so-forth that effect the risk of heart disease, cancer, and whatever else they're looking at. There's even things which interact with caffeine specifically to modulate or plausibly even reverse it's effects. All of these things work in egregiously complicated ways. But when I read the study and try to think what it tells me about my own situation, this doesn't matter since I can usually assume that my own exposure to these other factors will be typical compared to that of the study population- thus, I'll tend to respond similarly to caffeine as they did.

This approach is obviously has an abundance of limitations- it only tells me how I'm more likely to respond to caffeine or whatever else, but doesn't give any guarantees. And for someone who is different than the study population- a black woman living in Uganda versus a study done on white male freshmen at Yale, say- the results rapidly become less meaningful. But they do work.

Yep. The epitome of this is the infamous Finnish researcher who conducts ostensibly reasonable statistical analysis in order to prove his desired contrarian conclusion that it's beneficial to drink up to six pints of regular strength beer every day, and harmful to have days off drinking...

Even if a model actually succeeds in properly balancing the controls so that as well as controlling for basic demographics it also ensures its non coffee drinkers don't drink a commensurately larger portion of other caffeinated drinks or unhealthy alternative drinks or substitute for the caffeine hit with stronger drugs, and don't have a health reason for cutting caffeine or a cultural/social reason linked to other behaviours or diets, you've then got the problem that people with different genes and physical health likely metabolise coffee in very different ways, and to recommend more or less coffee to a particular individual, you've probably got to untangle all that too...

I've never understood this phenomena myself. Those who do this kind of research on a daily basis must have been rather smart to get their job. Surely, they must be intelligent enough to realize that what they do does not really add up to much?

Publish or perish.

I'm definitely an amateur at understanding biology, but having studied engineering; the inputs and outputs of the human body vary so widely that I have a hard time narrowing down one input to corresponding to one result.

When you think about the air you breathe, to the variety of things you ate (plus the additional microbiomes that inhabit the food, your skin, your gut, etc) it seems like we are just barely really understanding what the intakes to the body are.

Edit: here's a great point to start to think about it: https://youtu.be/bYOIhmZ0Osg?t=41m49s -watch for 10m

In some sense traditional medicine or traditional\religious healthy habits (I'm thinking something like kashrut) has way larger sample since it's been practiced for millenia and its populations still survived enough to transmit them to offspring. If grandma made it long enough to teach the grand kids some old traditions there's probably some merit to some of them.

The only thing that can be deduced from this observation is that these traditions are not deadly in the short term. After all, smoking is a tradition in some cultures, even though we are sufficiently certain smoking is harmful.

Circumcision is practiced by billions, yet there is no health benefits at all.

That's not true at all. Circumcision is linked to lower rates of penile cancer, lower rates of STD infection (probably why cancer rates are lower) particularly HIV and lower rates of bladder infections. In fact it was recommended that circumcision be standard practice in areas of Africa with high HIV rates.

Read this article, it demolishes the "health benefits" argument: http://blogs.bmj.com/medical-ethics/2017/08/15/does-female-g... In short, if male circumcision has health benefits, then female circumcision has too and even African tribes' rituals in which they pull each others teeth out because it prevents tooth decay!

Regardless of that, and assuming that there are major health benefits to circumcision, the Jewish and Muslim communities that practiced it for millennia, couldn't possibly have been aware of any. Because they didn't perform any epidemiological studies measuring rates of penile cancer and HIV infections. But they must have noticed a lot of babies and boys getting fevers and dying from infections shortly after the procedure was performed on them. Clearly, the rite lived on because "God told them to" despite the adversarial effects it had on their children's health.

Can you cite some substantiation for the claim of high morbidity and mortality historically resulting from circumcision of male neonates? I'm not tremendously in favor of the practice myself, as it seems unnecessarily traumatic, but I also think it's worth paying heed to the occasional fact, no matter how firmly you happen to be against it.

And I'm not especially impressed by that article you linked, either. Several of the sources it cites in support of its arguments, when examined, turn out to be tangentially related at best, and not at all supportive of the claims to which they're linked.

Do you really think mutilating people’s genitalia is a reasonable intervention to lower STD rates?

It’s my opinion that circumcision acceptance is based on a cultural/ideological blind spot.

Less STDs because of the hardened skin. Look it up.

I completely agree. Also, with a pop-science-y title like this, how can anyone take the article seriously?

I think this kind of information is funded by the caffeine industry. This is pure insanity. It took me a month to quick coffee (IT professional here) and to stop hating my life. Another 5 months to finally get completely over it where I didn't feel like I was dragging every day.

Now, I am free from coffee addiction and happy as I have ever been. No way in hell is that stuff good for you.

Read Caffeine Blues, it will wake you up for real.


It’s possible that you could have been addicted to something good for you.

Its effects vary. My programming productivity drops when I'm on caffeine because I get anxious. It makes me procrastinate a lot more because I get intimidated by the work I need to do.

Yes, coffee increases anxiety. I only learnt that recently. I'm cutting down on it!

I find that green tea is often more useful than coffee if you just want a mild push, since it’s basically low dose caffeine. It also has L-theanine which is a mild anxiolitic and can counter caffeine’s anxiogenic effect. Some also find that taking an L-theanine supplement (OTC) along with coffee can also counter most of caffeine’s anxiogenic effect while keeping the wakefulness and focus.

Thirded. One of the ways I thought/tried I could stop caffeine is by drinking only on the weekends, when there is no work pressure...

But then you sleep 5 hours on sunday, and monday we are happy again on the coffee train.

Just like milk, there is probably a sub population of people whose body chemistry is not compatible with caffeine or coffee. You may fall into that category.

I developed a stomach condition in 2014 that prevented me from eating fried foods, caffeine, alcohol and red meat.

It took almost a year before my cravings went away but after I never felt so good.

"I completely changed my lifestyle and never felt so good, therefore coffee is bad."

Maybe you're sensitive to caffeine, or coffee itself. I've tried going off coffee and feel about the same after a few weeks of normalizing.

Another anecdote: having even a little bourbon makes me feel completely terrible, however I feel fine after drinking any other spirit. It's just my bodies adverse reaction to some chemical component. Perhaps similar with you and coffee.

I heard stories like this, but I have hard time relating. I don't have problems not drinking coffee, I just like to drink it.

There were periods when there was really good tea at the office, and I would drink that, or mineral water.

Anyhow, believe you but can't relate as I and many others don't have issues with coffee drinking.

Yeah, what I find weird is this:


More than a thousand chemical compounds in coffee, area of active research. Does this imply that we don't know much about coffee yet?

And more anecdotally, what I find weird is that when I switch from coffee drinking to tea and soft drinks, there seems to be no amount of caffeine intake that make the withdrawal symptoms go away. For me, there certainly is something in coffee besides caffeine that hooks me.

Its also worth considering the strength of the coffee may be more than anticipated. For instance, a 20oz cup of Starbucks coffee has _more than double_ the caffeine found in 20oz of red bull. It always gives me a laugh when the "5 hour energy" commercials advertise "only as much caffeine as a cup of the leading premium brand of coffee" -- aka Starbucks. A 5 hour energy _also_ has more caffeine than a red bull. I always bring this up in these conversations because it was all such a surprise to me.

There are more than a thousand chemical compounds in anything you eat that came from nature.

We all have gene in our liver for making enzyme that breaks down caffeine. Due to small genetic differences, some of us have enzyme that breaks down caffeine quickly and others that breaks it down slowly. If you win genetic lottery and produce enzyme that breaks down caffeine fast then you flush out caffeine and end up reaping benefits of antioxidants found in coffee beans. If you have enzyme that breaks down caffeine slowly, caffeine hangs around longer causing health problems. That's all there is.

This. I’m a slow caffeine metabolizer and had to give up caffeine.

How do you determine you are a slow metabolizer of caffeine?

Anecdotal: If you aren't able to fall asleep as easily 6 hours after a cup of coffee vs 10 hours you might be a slow metabolizer.

Strangely enough, if you find yourself in this situation of having drank coffee too late in the day nicotine has actually been proven to speed up the metabolization of caffeine: https://www.ncbi.nlm.nih.gov/pubmed/3365914

I can usually drink coffee within an hour or two of bed. I don't normally do that but I can. On the weekends I drink 2 to 3 cups in the early morning around 5AM. Then around 2 pm I usually drink 1 to 2 more cups.

At 70 something my dad watched a TV show on ADD and said to my stepmom, I think I have ADD. He want to the doctor and told him the same. The doctor said, we don't test for ADD, instead we have assessment questions. He asked my dad, first question "How many cups of coffee do you normally drink?" Dad said 15 to 18 a day. Doctor said we are done. You have ADD.

He was on ritalin the rest of his life. I don't agree with having him on ritalin but that was not my choice. He died of old age at 83. Until a year before his death he had been very healthy. NEver got colds, the flu or anything like that. Had a little spring hay fever. That was all.

The way you present your doctor, if I told him I was taking 8 sleeping pills a day, he'd diagnose me with narcolepsy instead of telling me to cut back on the drugs.

My dad's doctor and not mine. Keep in mind this was antidotale from my dad. I'm sure the conversation was longer but that is how he (my dad) represented it.

Wow, I didn't know that. I gave up smoking a while ago and now think smoking is a terrible and costly habit/addiction, but I still miss smoking a cigarette while enjoying a nice cup of coffee.

I wonder if the metabolization benefits of nicotine actually made coffee more enjoyable on a physiological level.

An educated guess: you get stronger negative reactions to caffeine: anxiety/panic, aggression, insomnia, heart racing and/or palpitations, sweats, tremors/muscle spasms, dehydration.

That said, I don't think it's as genetically hard-coded as the the root comment suggested.

I've been through episodes (coinciding with when I was having debilitating symptoms of chronic fatigue and depression), when I experienced these symptoms (sometimes very severely) when consuming caffeine. As I've become more physically energized and mentally well, my tolerance for caffeine has vastly improved.

It’s weird I have the fast version of the gene yet I can’t sleep that night if I even have a small cup after noon.

Do you have a source for this?

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4242593/ In section "Genetics and long-term effects of caffeine" it goes a bit into details but here is relevant excerpt: "The finding of lower COMT activity with higher risk of myocardial infarction points to involvement of circulating catecholamines in caffeine’s effect on cardiovascular system, with the implication that slow-metabolizing individuals could be at increased risk due to decreased ability to handle the stress associated with caffeine-induced catecholamine response."

if you want to know more about caffeine in general this place sites all the studies: https://examine.com/supplements/caffeine/

Where on this page does it say that having this mutation makes coffee less harmful?

So the article touched on this briefly but I think it's a point worth exploring: a big problem with many sources of caffeine is also that sugar confuses the issue. Many people have an excessive amount of sugar with their coffee (personally I find coffee revolting and 4+ sugars is the only way I could cope if I were forced to drink it).

Other caffeinated drinks (eg sodas) are either sweetened (sugar or HFCS or have artificial sweeteners.

So about a month ago I decided I was drinking too much caffeine. I'm talking 600-700mg a day. I should also point out that my variance with and without caffeine is pretty low. In college for example I tried once to take caffeine pills to stay awake to cram. Not sure how much I took but it was enough that my hands were shaking. I still fell asleep just fine. Some people really do seem a whole lot more sensitive to this than I am.

Anyway, my reason wasn't coffee in particular but sugar. For years I've drunk artificial sweetener sodas and ignoring any other possible side effects I think the big problem is that they still taste sweet so it seems like they still feed the craving loop for sugar without containing any sugar.

It's early days yet but I think I can already notice some difference. Like I had ice cream tonight that I've had many times before and it tasted too sweet.

Anyway I think it's impossible to talk about caffeine consumption without also considering sugar consumption because they really do go hand in hand.

Caffeine is a stimulant and seems like it can be used to enhance some activities including athletic ones [1].

[1] https://www.theatlantic.com/health/archive/2014/03/how-athle...

> Anyway I think it's impossible to talk about caffeine consumption without also considering sugar consumption because they really do go hand in hand.

Not for everyone - there are people who drink coffee black with no sugar (especially espresso drinkers).

Yep. I only drink black coffee, no sugar, and I don't eat sweets, cookies, or anything. In fact, I mostly don't consume anything but coffee from I wake up until dinner time, 6-7 PM.

So you're repeatedly having coffee on an empty stomach? That can't be good for you.

Haven't noticed any of the supposed side-effects doing so could cause. For a while, not eating for hours was also supposedly bad for you. Then fasting started to show benefits. It turns out traditional dietary advice might not be worth jack shit.


One study found a slight increase in acid reflux when drank on an empty stomach, a problem I don't have, other than that there does not seem to be any associations with gastritis, ulcers, or dyspepsia.

Yes, intermittent fasting is said to be quite good for organisms. Maybe a form of hormesis. I'm unfortunately not in a position to comment much on caffeine's health effects aside from various interesting and likely true points of speculation but I find what you shared interesting and do not doubt for a second that medical science (including nutrition, and immunity) is not properly understood except by a rare handful who have the ability to see things whole.

I believe coffee has a lot of beneficial properties, but I have a slight concern regarding caffeine as it reduces CBF. That might impair cognitive functions. Supposedly you can mitigate some of the vasoconstriction with flavonoids.


I always drink my coffee black. I don't drink the stronger blends like you might get in a French roast or at Starbucks. I do dring espresso however a few times a year.

I think Starbucks tries to cater to people who like the flavours in black coffee, but enjoy drinking their coffee with dairy. My theory is that it's 'roasted to pair with dairy' and if you drink starbucks coffee black, cold brew, or espresso without dairy, you're missing half of the 'starbucks' flavour.

I prefer my coffee black, so that makes starbucks worse than most fast-food coffees flavour-wise (though I still enjoy Starbucks locations and amenities better :D)

This, like some other comments here, are variables easily controlled for.

Coffee is not supposed to be sweet or iced for that matter. The only proper way to drink coffee is either black or with a little milk. :)

To add to your anecdote - I also have an extremely high caffeine tolerance and can fall asleep just fine even if I've had an espresso (or two!) after dinner. Similarly to you, I don't really notice the lack, as I rarely drink caffeinated drinks on weekends and have no noticeable dip in energy.

I think your ice cream experience might have an entirely different cause - you were used to stimulation from particular flavors, so when you quit consuming sweet food/drinks. your perception of ice cream was like a bombshell for your tastebuds.

Now, it's entirely possible that artificial sweeteners have detrimental effects on your gut biome or causes a reward response, which create cravings but I'm skeptical until more literature is published on the subject.

Observation: Coffee studies often report (in headlines and abstract and body) consumption in terms of cups.

At best, this refers to a standardized 250 ml or 8 oz measuring cup (unfortunately, still rarely what "a cup of coffee" generally means to those who read these headlines and adjust behaviour as a result).

At worst, the term is used to allow for ambiguity and variance expected in self-reporting.

I recognize there are many other variables that are even harder to measure than beverage volume, like mg of caffeine or diterpenes or antioxidants. But "cups" just seems so loose.

Related question: Is there a somewhat accurate amateur method of measuring caffeine content? I vary my beans and roasts and method a fair bit for fun and taste. e.g. various beans, light vs medium vs dark roasts, varying apparatus, mass of beans per "cup", filter types, and brewing time. I would like to have insight into how much caffeine I'm consuming.

Ahh, now here comes the fun part. There is no standard.

250ml is 8.5 ounces. Some places in Europe standardized on this.

A cup of anything else is 8 ounces.

A "cup of coffee" (the actual unit) is 6 ounces, and this is the standard everywhere where 250ml isn't, and we're not in Japan; but even though the US follows the 6 ounce standard, the USDA considers a cup 8 ounces on their nutrition table.

Japan has standardized on 200ml (or about 6.7 oz).

What SHOULD be measured is not liquid volume, but bean weight (measured in grams; even Ameicans measure it in grams when they're the type to weigh it instead of just throwing ambiguously heaped tablespoons in); and then shifted according to that blend's particular caffeine content (outside of specialty products with high-caffeine bean variants, caffeine content can vary about +/- 50% depending on the origin of the beans (roasting does not effect caffeine content meaningfully, although the myth lives on)).

There's enough anecdotal evidence here to fuel a study in it of itself. I'm surprised there isn't an app out there where you can opt into any number of studies. Surely there's potential for an app like this.. Anyone want to get together and build it?

* edit - maybe it's just an app where you like 'Facebook' all your medical history, and post daily diets, health issues like headaches, acne, etc...

All the data is public and accessible by anyone to trend. There would be no usernames though, everyone just has a guid and all the guids can find people like themselves and chat with anonymity.

Open for massive fraud as an elective system which might be very damaging for the endeavor itself and could completely discredit it.

We have an open position for you on the team to use machine learning to root out fraud ;)

This is something I've also had in mind for a while. I'd be interested in working on this.

DIY clinical trials with 23andMe DNA data integrated? Sounds awesome.

Seems like an old school system that sucks as it is and is ripe for disruption.

I can help with UX. DM me, my Twitter is in my profile.

I only drink one cup per day and I only started when I was in my early 30s so I guess I'm not getting much out of it.

Some people like me are very sensitive to caffeine. I wonder if we the jittery ones process caffeine slower and could that be a disadvantage.

Acrylamide due to roasting isn't a great thing either.

Hot liquid ingested every day may be a risk for throat cancer. https://www.cancer.org/latest-news/world-health-organization...

Your link’s first paragraph states coffee is usually consumed at temperatures below the risk threshold. A couple paragraphs later is states that coffee has been removed from their list of beverages they’re worried about.

But that information seems to change every few years. The acrylamide is the newest twist created during roasting, even cold brew can't escape acrylamide.

For me, I have to be careful drinking coffee because I have GERD if I drink too much coffee my throat spasms and at night I cough up stomach acid while asleep. It gets into my lungs and over time damages lung tissue.

Even for coffee roasters, the people near the coffee are at risk of lung damage from whatever roasting coffee emits. https://www.jsonline.com/story/news/investigations/2017/09/2...

So just because cancer.org isn't worried about it, means that you shouldn't be?

The American Cancer Society is extremely misleading and biased in their opinions imho.

They basically support whoever pays them to.

They actually suggest that you eat meat on their "healthy eating recipes" page for example. [0]

I don't know a ton about nutrition and cancer... but I do know that eating meat is not suggested by most nutritionists who understand those subjects better than I.

[0] https://www.cancer.org/healthy/eat-healthy-get-active/eat-he...

Cold brew for the win!

I wonder what the health benefits are for different caffeine metabolizers (i.e. for different CYP1A2 genotypes). The source article only mentions that slow metabolizers have a higher risk of hypertension, but is that outweighed by the other benefits?

4 cups of coffee in a row don't do anything to me and adding more makes me asleep. I guess I am one of those for whom coffee is just one of ways to stay hydrated and nothing else. Similarly alcohol, it doesn't affect my thoughts just coordination, I am not more open/brave/socially whatever with it. I guess I should be a monk...

I used to be like that until my 30s but suddenly it changed. Now I can't sleep if I drink just one cup. It also makes me uncomfortably hyper.

Many people in this thread are sharing that coffee/caffeine doesn't work for them, and then others are replying that it must not be true, there's scientific evidence!!11 Look, one scientific study doesn't mean it will work for everyone. It's very likely that there is plenty of counter evidence available, as with almost every study. We all live by our own personal guidance, and that's fine if it doesn't hurt anyone. Coffee or not, it's great what works for you. But those replying here saying that person's personal experience mist be wrong, are just rude and ignorant.

This isn’t just one study, it’s a meta-analysis of “over 200” studies.

If I drink that much caffeine I get very sensitive to anxiety attacks.

Yeah I used to think anxiety attacks were something I could not get, but then I got into a stint of drinking 1 (!) cup of coffee daily when I was under pressure to get some boring work done, and made a habit out of that for maybe 3 months.

During those months, I experienced anxiety attacks for the first time in my life. I did not realize at first that long term (for me, 3 months) coffee consumption slowly helped drive myself towards constantly doing more than I realistically had the energy to do, somehow triggering these very anxietic episodes couple of times, where I was feeling like I was in danger, it was hard to breath, and I was panicking, I really didn't know what was happening.

Later I realized coffee did this. There are studies of coffee putting the body into a state of fight-or-flee constantly, rising the heart rate and making people very jumpy, so that might explain why this happened.

Also, I've been noticing that drinking coffee tends to over focus my focus on one task and not see to whole picture, so it is very easy to go in one direction too far with a project for example, and just start fine tuning whatever little details come at me, when more better would be to see the big picture again and change directions.

I can hardly see how coffee is a good thing on a global scale, except for the work force who want to do stuff that is not otherwise interesting.

Drinking decaf ~one week a month is a good way to reset your tolerance

This doesn't make sense. Caffeine has a half time of 4 hrs (3-7 according to this source [1] but lets assume 4 for the sake of argument). So if you consume a cup, in 4 hours, you got 50% of caffeine remaining. If you then drink another cup, you go from 0,5 to 1,5 and after 4 more hours you are on 0,75 which is 75% of your first dose. We're then 8 hours in the day. 12 hours into the day you're on 0,375 and at that point you're winding down.

If you'd drink one week a month decaf (assuming you can enjoy the taste. I dislike it) you get caffeine withdrawal the first day, and the other days you don't. But as soon as you start consuming coffee again, you also get withdrawal symptoms because the half time is ~4 hours.

The way I deal with it which is the correct way is limit coffee intake to 2-3 cups a day in the morning/afternoon. None in the evening because it will cause sleep deprivation.

[1] https://en.wikipedia.org/wiki/Caffeine

Personally, I've found drinking that much coffee is very likely to give me headaches, and has even given me a couple ocular migraines over the years (not fun). Not to mention making me feel terrible once the caffeine starts to wear off in the evening.

Add in the caffeine withdrawal afterwards, and I've decided that it's best to just avoid caffeine altogether. Overall, I feel like I have more energy now... but it does require being more careful about getting enough sleep.

Haha for me it's the opposite. Caffeine cures my migraine the same way rizatriptan does. They are both vasoconstrictors and help reduce my throbbing migraine.

Now is as good a time as any to remind people that things aren't bad for everyone just because some people are sensitive to them. The hysteria over gluten, generally reasonable amounts of salt, peanuts, etc. in the diets of people who are not sensitive to them always irritated me.

I have to be careful with caffeine personally because I haven't needed to have it for the last few months, so when I do have it, it usually seriously upsets my (unbounded) sleep cycle if I don't take care to go to sleep at a regimented hour.

Go easy on the coffee. You'll discover it has caused you acid reflux, long after you can do anything about it.

Also: sugar masks the flavor. Good coffee tastes best with just cream.

There's an excellent, clear summary of this study on the NHS website:


I feel like I have a real problem with some scientific studies on the human body, which apparently link things to specific outcomes and later on reverse those links and sometimes even linking the opposite to the same outcomes. As a researcher myself, but not in a biological field, I believe more and more that it is just insanely difficult to understand the complex interactions inside our bodies. This doesn’t mean that I’m against this type of research, on the contrary, we need more and more studies.

Right, so it is 11 a.m. - who is for coffee? So I pick up the tray, go down to the kitchen, make everyone a cup of tea/coffee/defac-coffee and pick up a can of some fizzy drink for that guy who lives off energy drinks instead of coffee.

In the kitchen I have a joke with the guy from accounts as well as have a really positive buy-in for the new 'aggregated accounts' plan. I have some chat with the cleaning lady, she smiles, I smile. Someone else gets doors for me, I say please and thank-you. Finally beverages get served by me to my colleagues. Everyone is happy.

On the way to and from the kitchen I have got the blood circulating, not a very big walk, certainly not a gym workout, but all moving is good in the sedentary office world. Yes, it does take a lot of muscles to smile, and just with the light convo needed to get to the kettle and sink I have had a little workout. Unlike press-ups I can put my heart into a smile.

So what happens if I am in a mood and can't be bothered to make tea for the rest of the team? I sneak into the kitchen and make a coffee just for myself. Or if it is the weekend and I am home alone, with no interaction with people during the consumption of coffee.

On aggregate I do make coffee and it be a social thing rather than a loner thing. We are social animals and the act of sharing coffee is probably better for our well being than whatever is in the coffee. I don't think it is possible to do studies without the bigger social picture.

So could claims that 'coffee is good for you' stack up, even with the above?

In my anecdata there is also the girl I sit next to that is not in the 'tea round system'. She makes her own drink, and will tend to have a jogger style water bottle at hand at all times. She will also make her own infusions - ginger tea etc, but not a round for everybody. Because she just serves herself then she is not in the kitchen for as long as me, not needing to converse to complete the task (no tray). Furthermore, she does not get to greet everyone in the team, or to have that special thought for them, e.g. mug colour preference, tea/coffee strength etc.

So, anecdata, but, if coffee and the sharing of coffee is important, then the claims that 'coffee is good for you' could stack up but it not be causation/correlation on the caffeine, even if that appears to be the case.

Can coffee still be more beneficial than harmful if you suffer withdrawal effects? I have some co-workers who get headaches if they try to have a morning without coffee.

That's a known thing. Drinking coffee blocks adenosine receptors (which affect tiredness). In result, they increase in number to compensate that. So if you stop drinking coffee, the increased number of receptors causes more intense feeling of tiredness. If you stop drinking coffee for a long time, the number of receptors adjusts back down.

If you’re worried about Caffeine withdrawal drink decaf. There are good quality decaf coffees available.

previously: https://news.ycombinator.com/item?id=15679522

The relative risk vs coffee consumption curve fist goes below 1.0 (no coffee = 1.0) and reaches minimum around 3-5 cups then starts to increase slowly again. cardiovascular disease and stroke risk go above 1.0 after 9-10 cups per day.

The study mentions that results may not apply to unfiltered coffee (eg, French press, Scandinavian boiled, or Turkish/Greek coffee). Other studies have shown that cholesterol-raising factor in coffee does not pass a paper filter.

NOTE: Cholesterol increasing effect in coffee is not from dietary cholesterol. It comes from cafestol and kahweol (diterpenes). They seem to have adverse effect to cholesterol regulation in the body, http://www.annualreviews.org/doi/10.1146/annurev.nutr.17.1.3...

Consider supplementing drinking coffee with taking l-theanine. You can read more about the benefits at https://www.reddit.com/r/Nootropics/wiki/beginners/

Magnesium replenishment also helps, esp. with >2 cups of coffee / day.

L-Theanine is great when combining with coffee, but at least for me when I've experiment with this combination, if doing it routinely, it really can start to deplete maybe the serotonin levels or something in my brain, because I start to feel more dull in a way, it's hard to describe, it's kinda like this slight fuzziness.

Just for more info, I've been experimenting with 200 mg of L-theanine combined with one cup of coffee. Not something I would take in long periods, but definitely useful for those stints where you just have to get something done and need the stimulants.

L-theanine is good also for relaxation alone, and calming the nerves down, I sometimes take it by itself if I feel too anxious also.

That's interesting, your findings are contrary to what's generally reported. I haven't found data confirming any negative side effects for l-theanine including prolonged use. I suppose it all depends on an individual and dosage of all stimulants.

Yeah, it's interesting to hear that people have no side effect. It's not anything really substantial, but there is definitely some side-effect. I'm used to being really sensitive to any substances though, for example I couldn't drink 3 cups of coffee a day, that would drive me totally hyper.

But after all, that calming effect has to come from somewhere with L-theanine.

We seem way too focused on whether coffee is good or bad for our health.

All I know is it tastes fucking delicious, it makes me feel good, and we've been drinking it for generations. If I die earlier because of it, then so be it. At least I'll have had an enjoyable coffee-drinking life.

> If I die earlier because of it, then so be it. At least I'll have had an enjoyable coffee-drinking life.

On the other hand if coffee drinking causes strokes you could live for years with severe impairment.

I'll take my chances and just not worry about it :)

I don't think I've ever heard of a person in old age lamenting, "If only I hadn't enjoyed coffee so much!"

Cigarettes on the other hand...the effects of those are a lot more clear-cut.

At one point a similar sentiment could have been expressed about smoking

I don't know. When I drink more than 2 cups my sleep suffers and even my personality changes. I get pretty hyper and less patient. With my girlfriend I can tell immediately whether she has had coffee just from the way she talks.

Try to cut off the caffeine consumption by 3pm and your sleep should not suffer (based on the half life of caffeine and average human adult body weight).

Disclaimer: I consume ~4 cups of coffee per day between 8am and 3pm and get ~8 hours of sleep per night.

The CYP1A2 gene affects how quickly you metabolize caffeine. Stopping at 3pm may not be enough.

I’ll check my CYP1A2 SNPs on 23andme in the AM and report back.

I'm not sure if that's sarcasm or not. Maybe I'm just not hip.

Not sarcasm at all. Last time I checked, 23andme reports if you’re a fast or slow caffeine metabolizer. I just don’t recall offhand which I am.

Why would that be informative? It doesn’t tell you your protein expression levels nor effective enzymatic activity.

You don't know what - if this general result could be invalidated by your personal experience not matching it?

How big is a "cup" of coffee in this study?

Typically my "cup" measures 2 cups based on the coffee pot.

I hope 10 cups a day are ok :)

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