And before someone asks "But what if it's .. instead?": Yes, they controlled for lots of things:
> lower risks for all-cause mortality after adjustment for lifestyle, sociodemographic, and clinical factors
The patient data is from UK Biobank, which has quite a bit about each participant. While they can't control for everything (like factors that aren't documented), they can control for a lot - probably including whatever possible confounder someone jumps to.
Although it's still subject to the limitations of an observational study, 171,616 people is a big cohort, mortality is clearly measurable, and the observed effect is really large. It's worth paying attention to.
I decided to go the other way and ignore all the potential confounders and just cargo-cult the hell out of all of this stuff. I'm bound to hit a few of the actual factors.
Now if you'll excuse me I need to go drink my coffee and glass of red wine while doing yoga/meditation, then eating Mediterranean meals during my intermittent fasting period while making more that $75K per year, sleeping 8 hours a day and living in a "blue zone".
Well, I guess you're more of the live fast die young crowd and shouldn't expect to be here much longer, not without copious amounts of carrot juice, chili peppers and olive oil.
> As result, in the data, sugar starts to look…a lot worse for you over time. In the earliest period of the data there is no observed correlation between the sugar measure and BMI (see below) but by the latest period, it’s hugely correlated. The “sugar-makes-you-fat” story only shows up in the last few years, coincidentally during the period when sugar is less consumed by individuals who exercise, do not smoke and are better educated.
It's also important that people understand what "control for" means in an observational study.
Nearly all observational studies that you read draw their conclusions from regression analysis (or something, such as a ANOVA, which is a can be trivially implemented as regression analysis).
This just means that a linear model such as this is used:
Then, unlike in machine learning, researchers look at the value of the coefficients and most importantly the confidence in the coefficient value. In a simplified example:
Where b_intercept will represent the life expectancy in general. Then b_coffee (since drinks coffee is binary here) will represent whether or not coffee adds to your years of life. If it's negative it means drinking coffee reduces your life expectancy and if it's positive it means it increases it. In statistics we also look at how certain we are in b_coffee in terms of standard error and p-values. For example if b_coffee is say 5, meaning it adds 5 years to your life, but our standard error in this estimate is 4 (ie 95% chance that the real impact is between -3 and 13 years). In this case the p-value for this coefficient will be higher than necessary to conclude "statistical significance".
But suppose the standard error is very small, like 1 year, where we are virtually certain that coffee does improve life expectancy. To control for say, college education, we just add that coefficient to our model.
The magic of regression analysis is that if, in fact, people that go to college life longer and people that go to college also drink more coffee, the our coefficient for b_coffee will change in this new model to reflect this. If for example it were to become negative now (with a low p-value) what we would conclude from this model is that coffee is in fact bad for you, and college is good for you and it just happens that a lot of people who go to college also drink coffee.
Just as even the most advanced AI is often just a lot of matrix multiplication with non-linear transforms, the vast majority of observational studies are drawing conclusion using linear models. In practice, as you add more variables to your model, you tend to get a lot of tricky to interpret results. Regression analysis is a remarkably powerful tool, but it is important to remember when you see publications this is what is really happening and there is a lot of room for subtlety when interpreting these models.
Yet all you have to do is miss a factor and you've ended up with correlation.
As a simple question, what about people who have weak stomachs or hearts? My mother doesn't drink coffee because it "makes her heart beat too hard". How, with no actual medical data for "coffee makes my heart beat hard", do you control for that? Is that something to control for?
This is the "caffeine and healthy pregnancy" problem. We know women who consume less than ~200mg of caffeine tend to have healthier pregnancies.. but if you can drink 5+ cups of coffee while pregnant and not get overtaken with nausea, that might indicate something is already wrong.
An important limitation which is often overlooked is that when you "control for" something by entering it into a regression, as you describe, you are only controlling for the linear effect of that thing.
It seems to me that this problem is totally fatal for large-scale epidemiological studies with many factors, of which many are sure to have nonlinear effects.
Well put. I ultimately view observational studies as hypothesis generators that can spur research into more targeted questions all the way down to the biochemical level.
Yes, science is really hard, and it’s a good point by Oster, but you’ve got to think about the idea that the folks who conducted this study know as well how hard science is, and for them to publish this anyway means they (and their reviewers) did a pretty good job dealing with this issue (and many others).
None of this is conclusive to the point where no further study is necessary, but I’m guessing this study will make some institutions think/rethink their guidance on coffee consumption.
> for them to publish this anyway means they did a pretty good job
The standard shouldn’t be “we did the best we can” for the sake of publishing. It should be “is what we’re doing useful”.
> I’m guessing this study will make some institutions think/rethink their guidance on coffee consumption.
This is the major issue with all these kinds of studies. The absolute last thing they should be doing is influencing public policy. Data that’s more or less garbage but you treat it like it’s solid because it’s “science” is harmful.
I'm sorry but I completely disagree; the standard absolutely should be "we're doing the best that is currently possible to determine how things work". Asking for more is entitled and completely misunderstands the nature of science.
We need to have a way to figure out what to tell people to do, and we're doing that, whether you like it or not, with imperfect information.
Also not for nothing, this data is not "more or less garbage". This is about as good as we can do in science right now, and honestly your tone is pretty terrible. It sounds like you want religious levels of certainty and you feel you deserve that.
Science doesn't get much more certain than this (and this is far from very certain in any sense), there is no "better" way to do things that the researchers just lazily didn't follow here, and your suggesting that such is the case is ignorant and selfish. You should feel bad for what you've written here.
A decades long rigorously controlled RCT in human nutrition science is practically impossible. Even if it were possible the scientist would still have to choose variables to control for in their population selection.
You don't get points for trying. If observational 'scientists' can't discern something about the world which stands up to scrutiny then they are wasting everyone's time, including theirs.
>but you’ve got to think about the idea that the folks who conducted this study know as well how hard science is, and for them to publish this anyway means they (and their reviewers) did a pretty good job dealing with this issue (and many others).
What makes you say that about this paper specifically? Certainly in general there are career incentives for authors to publish papers which are not very conclusive, and we know that relatively useless observational studies do get published.
I'm kinda "done" with observational studies. It seems like for the last 10 years that's all we get. And every time the studies come out they contradict that last one. When are we going to see the actual coffee atoms attack bad viruses and shit (kinda a joke but seriously, when are we going to have that visibility into exact pathologies).
My family has a history of all kinds of diet/exercise related issues. Diabetes, kidney issues, heart disease. It's sort of funny if you search up diets useful to avoiding and or living with these problems you'll generally find it's the diet we all know. Eat lots of vegetables, eat whole grains(Wilfred Brimley told me to eat my oatmeal, that SOB was right), if you eat meat do so in portioned moderation, eat fruits but not to excess.
I don't really know anyone personally who doesn't know what they're doing bad to themselves. When I order a salad and my buddy orders a butter seared steak and fully loaded baked potato (after he ate a whole pack of sour patch kids at the movie), and I don't say anything, but he says "You've got to enjoy your life!" I know he knows. Because I've done that, and I knew. I'm no Sporty Spice but if more salad than steak, and more water/tea than soda/beer, means I don't have to go to a regular dialysis appointment I'd consider that a tick under "enjoying life," personally. But if I could eat the steak and potato and candy and just offset it with more coffee - by god, that's the ticket.
> means I don't have to go to a regular dialysis appointment
I'm going to copy a comment I made regarding Type 1 Diabetes on another post about a year ago. It's relevant because what you're saying, though very true, comes down to immediate effort versus delayed impact. I think people who fail to control their diabetes largely do so for the same reason people fail to control their diets...
> I am going to make a weird, but IMHO apt, comparison to Type 1 Diabetes. T1D is an attritional disease caused by the pancreas's inability to produce enough/any insulin and the list of complications is long and deadly. As someone who has lived with the disease for decades what makes the disease particularly insidious is immediate effort versus delayed impact. The disease affects everything...every single part of every single day. Eating, sleeping, exercising, traveling, finances...everything. And to be on top of everything is extremely effortful. However the impact of not taking enough insulin, of not checking blood sugars frequently enough, or living with high blood sugars, is delayed. Today's transgressions may not be punished for decades. It is no shock to read about poor therapy adherence when the effort is immediate (and constant) and the effect is delayed (and therefore hypothetical). I see the same issue - immediate and constant effort coupled with long term hypothetical effect - with protecting one's privacy. Obviously one should do the right thing. But many won't.
Salad's funny because it can mean anything from "lean chicken breast on lettuce and tomato with a tiny bit of balsamic and oil, 200 cal at 60% protein/20% carbs/20% fat" to "mayonnaise potato and bacon, 1000 cal at 10% protein/20%carbs/70% fat," and pretty much everywhere in between.
Not to nitpick what you're saying, anyone on HN who orders a salad is probably thinking about what's in it, but it's worth pointing out that the category is so broad that it can be deceptive for anyone who doesn't read the fine print. I read an article the other day complaining that a 324 cal Subway 6-inch didn't taste as good and wasn't as filling as a 685 cal Sweetgreen salad bowl.
> to "mayonnaise potato and bacon, 1000 cal at 10% protein/20%carbs/70% fat,"
I never thought about something like that being considered salad... but maybe I'm the weird one? Also, whoever orders that knows that this is not healthy right?
As a Californian, I always have to remember that in other parts of the country salad dressing is applied much more liberally. Asking for light dressing in Chicago yields a similar result to asking for heavy dressing in LA.
I agree with this sentiment. Health studies are basically an oscillation between different diets these days. I never know when a new study will come and debunk yesterday's fad diet.
Some of the contradictory ones are the most interesting. Such as the contradictory studies with coffee consumption, which eventually pointed to filtered vs. unfiltered coffee giving different results (so studies done on populations drinking mainly filtered coffee differed to populations drinking mainly unfiltered). I also find it is worth looking closer. The headlines in the papers might be contradictory, but a closer look indicates the studies are actually measuring different things and they are not contradictory at all, perhaps even reinforcing.
Coffee is a strange one though. I think I've only seen 'coffee is good' in recent years, but I'm wary because I don't expect 'coffee is bad' studies to get the same sort of publicity.
That kind of work is hard, expensive, and likely to be fruitless. And in the case of many softer sciences it would more or less remove the need for the field (in their current forms). Sociology is a band aid until we understand biology better.
That being said I agree with you entirely and we shouldn’t shy away from hard problems because of this.
>That kind of work is hard, expensive, and likely to be fruitless.
Don't forget that the "fruit" for scientists is fame, not the truth. Anything that can get headlines and conference talks is a good thing, regardless of whether or not the methodology even makes sense.
>Don't forget that the "fruit" for scientists is fame, not the truth.
This is a pretty shocking thing to say. It's not true whatsoever for the field of physics. Is there a particular field or a particular experience you're reacting to? I think I'm overreacting to how general your statement is.
Feynmann's classic "Cargo Cult Science" for anyone who hasn't seen it yet. And for those of us who think it should be read and re-read at least annually and the time has come:
It's a 5 minute read. Arguably the 5 most intellectually productive minutes we can spend. (Well at least for me, anyway).
Now that ESP, paranormal, telekinesis research is thoroughly dead, (exposed by magicians like James Randi?), psychology still remains mired in it all. To the credit of a minority in that field they're having a go at getting it back to science and I wish them all the luck in the world. https://en.wikipedia.org/wiki/Replication_crisis
My understanding is that for vast amounts of "What food is healthy, what kills you." Research, epidemiological studies is all we have. They're obviously limited, easy to get wrong, easy to fool yourself (and you're the easiest person to fool!) The supply of identical twins, who are willing to commit to life long diet differences with rigor and make all the same choices outside of the study is, well, kinda low.
The statistics being used for these things is still under active development and being improved. Can it ever be done properly? Well I guess so. I think we're pretty clear on the smoking, cancer, heart disease, stroke link nowadays, right? And those studies have to have been similar.
It's interesting that scientists have to raise funding, publish or perish and so on to even have a career at all making them part P.T. Barnum. Fenymann, for all he didn't need to do that because of the different era, reflected "glory" from Los Alamos etc. really was capable of putting P.T. Barnum to shame while at the same time being the most devout adherent to and proselytiser of scientific principle & purity. So good and so lucky he could keep his hands clean?
Is there no academic misconduct in physics nowadays? None? I'd believe you if you told me so & why.
its not just fame, University 'Research' Centers are completely overrun with politics. I noticed after mapping diabetes, obesity, and excessive alcohol consumption that high levels of obesity almost perfectly overlapped with diabetes, except in areas with excessive alcohol consumption. I brought it up during an ideation session, but it was immediately dismissed as 'SES (socioeconomic status) must account for it, don't look into it further. when I lied and said these are higher levels obesity which is correlating with soda consumption, they wanted to write a paper / grant.
its leading to junk science, and large swaths of people are losing faith in what we are labeling as science.
Observational studies should only be used to conclude "maybe we should investigate this" - as in what you're asking for. Maybe let's try to elucidate some biological/chemical pathway that may be responsible for such a significant observed result. Or maybe let's find some confounding factors and learn why!
But pop science news interprets it as a causation.
Would we be ever able to conduct such a study? We'd need to have clones bred for that purpose since birth in exactly the same conditions - and even if we had that, you'd never be sure it would transfer well onto people living free lives. So, these weak observational studies are all we have.
Note that observational data can come in strong flavor as well, as in natural experiments, but I’m not holding my breath on a quasi-random decades-long coffee shortage striking half of any population soon. There’s always a chance a situation of this kind is ongoing somewhere though I guess?
This got long, so, here's a TL;DR: Observational studies on humans are basically the best you're gonna get for most purposes. Other animal models (primates, dogs, rodents) have problems, but rodents are the best compromise. By using rodents to screen new interventions, we actually end up benefitting humans sooner than if we'd just started with people in the first place.
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Right. IMO anyone criticizing observational studies on humans needs to overcome the idea that it's hard to do controlled studies on humans, and when it is possible (e.g. vaccine trials), the studies don't last very long, because you can't really control peoples lives that long and there tends to be significant attrition over time.
Theoretically, chimps would be the next best thing, but experimenting on chimps is ethically questionable as well, and they also live a long time. That's great for chimps, but not so great for biological studies where you want to observe the effects of an intervention over an entire lifecycle. Monkeys would be the next best thing after chimps, but experimenting on monkeys has the same issues as with chimps.
Among common experimental animals, that basically leaves dogs and rodents. Dogs are relatively large and hard to deal with compared to rodents, and their relatively long lives (compared to rodents) makes them difficult to selectively breed. Even if we modified the embryos using CRISPR or something to include genes that were of interest, a dog's gestation period is about 3 months whereas for rats and mice it's about 3 weeks. Likewise, Beagles (one of the more common experimentally used dogs due in part to their relatively small size and friendly disposition) live for about 12-15 years, whereas wild-derived mice and rats both live around 2-4 years in captivity. The general public is also much less concerned when rodents get euthanized as part of an experiment than when dogs do. Whether that should be the case or not is somewhat debatable, but, nonetheless it is. It's all a big trade off between fidelity and logistics, but shouldn't an audience like HN's consisting of a disproportionate number of software people compared to the general public actually appreciate that? ;)
So, rats and mice a really the only reasonable choice if you need to experiment on a live mammal in less time than it takes to actually get a PhD. But, then that triggers the chorus of "in mice" replies we see to pretty much every biomedical article on preclinical research here. And, there are undoubtedly interventions that would work on humans that don't work on mice, just as there are many interventions that work on mice but don't transfer to humans. We miss out on those, but the ones that do make it through rodent trials and into humans got there by a process that weeds out a lot of things that couldn't possibly work, which ultimately means humans benefit sooner by starting with mice than if we just used people in the first place.
This is a fundamentally wrong rule because, as we have learned, researchers and reviewers basic competence has come into play repeatedly. The further you get from quantitative physics, the worse it gets.
That said, if you are going to criticize something based on the idea "this result doesn't agree with my preconcieved notions so I'm going to say that their sample size was too small, the effect size was too small, or they made some sort of incorrect calculation, and conclude the paper can't be trusted", you owe it to yourself to read the paper carefully enough that you can make the determination they made a major error.
Unlike most people, I read the conclusion, then the methods section. For most papers I can't get enough from the methods section to conclude that I trust the authors to make their claim, because most methods sections are missing major details on how the corrections/controls were made.
Should we also look at final code assuming the programmer and their code reviewers lack basic competence? Or do we assume they made a best effort given their abilities and may have still made mistakes?
I believe the latter, and the rule I mentioned also leads to that assumption. Otherwise, why read the studies at all? But that's not what people here do.
> missing major details on how the corrections/controls were made
I also make an assumption that some corrections/controls are so obvious within their field of study that they aren't worth documenting - that it's only "average joe" readers who assume they aren't being done.
It is, in a way, akin to asking why programmers didn't document how their JWT is secured.
I don't compare software engineers and scientists by the same metrics. The important thing about a code review request is that it contains everything required for me to reproduce the effects of the code change in my own hands. Science does not require that- instead, the methods is typically the "least descriptive and helpful representation of what was done" (especially in the case of very complex biological experiments) and can't be reproduced with nontrivial effort.
BTW I've definitely gone into code reviews assuming the programmer lacks basic competence and been right. Other times, I've had to rollback other people's code (or stop a rollout) because an ostensibly genius programmer who made a change (and got a review from a starry-eyed junior) wasn't using their basic competence or testing their change at all.
Bad example. While the tokens themselves can only be secured in a handful of ways, JWT auth implementation is notoriously tricky. Even the official docs of some well known packages promote insecure practices such as storing tokens in browser localStorage.
There is a big difference between "here is what I think the authors did wrong" and "I did not read the paper, but did they even account for <obvious thing>?".
The former is perfectly fine and encouraged. The latter is incredibly rude and derails discussions.
Relatedly, you took the rule incredibly literally just so you could critize a strawman...
> Unlike most people, I...
Yes, yes, you a very smart and everyone else, in particular me, is an idiot...
Considering the average quality of software, I'd say people in the tech industry are quite low in the pecking order of who can criticize whose professional competence...
As someone who reads a lot of published research, no, that is a terrible rule and a lot of garbage gets published. Both historically and now there is no shortage of bad science that gets published, or good science that gets really misreported.
Studies don't have value just because they are a study.
Put another way, just because Cosmo publishes an article doesn't mean it's true - but Cosmo does also publish true articles.
Plenty of studies are great and move our understanding forward. More studies answer a very narrow - but important - question. Some studies are just inconclusive, but have value too.
You should read studies. You should evaluate the quality of studies as part of integrating them and their conclusions. At the same time just because something was "a study" or got published doesn't make it true or good or useful, anymore than being written in blue ink makes something truthful.
The value of science is that it does not require faith.
If someone were advocating making policy decisions based on astrological charts, I would read and comment in such threads despite not trusting astrology on a fundamental level.
I personally would go quite as far as to say that purely observational studies have as much predictive value as astrology, but "observational studies are as reliable as astrology" is a better first-order approximation of my opinions than "observational studies are as reliable as large-n randomized controlled trials".
A specific form of bad research which could be at play here: The researchers programmatically searched the space of possible control variables to include until they came up with a model which maximized the apparent effect size for coffee, so they could publish an interesting & widely cited paper that looked good on their resumes.
With N different control variables to either include or ignore, that's 2^N possible sets of control variables. Odds are decent at least one of those regressions has a large effect size for coffee.
I would trust this sort of research more if instead of publishing a particular set of control variables obtained by an unspecified method, the researchers chose 100 of those 2^N possible sets of control variables at random, then published the average effect size from the 100 resulting regressions. Ideally they would make the code to reproduce this average effect size publicly available, so anyone could easily replicate using another 100 randomly generated regressions.
> On Reddit's /r/science board, there's a base rule that "criticism of published work should assume basic competence of the researchers and reviewers".
Since most studies/publications cant be replicated, I'd say basic competence is not warranted.
I don't think it's questioning anyone's competence to suggest that a single scientific result might have confounding factors. This is one study done by one team. If the result was repeated in several studies, all coming at it with different viewpoints then I'd start to believe the result. In this particular case though, there seems to be new research coming out every few months saying coffee is good or bad for you. If the results look like that then it's hard to put much weight on any single one of them.
> I don't think it's questioning anyone's competence to suggest that a single scientific result might have confounding factors
Honestly - I do. Basic competence in creating a study would definitely include identifying confounding factors that are directly relevant to the study being conducted. It's a basic part of the scientific method - both in creating the hypothesis and creating a test against that hypothesis.
I don't think reddit and in particular /r/science should be held aloft as a beacon of reason and good thinking. The pseudo science and junk that is regularly upvoted there proves that they should more frequently question the basic competence of the researchers and reviewers.
> And before someone asks "But what if it's .. instead?": Yes, they controlled for lots of things:
I'm no experiment designer but I fail to see how you can control for variables when the field of the experiment is "life". There are an unlimited number of variables, wouldn't you find tonnes of meaningless correlations ?
The set of variables is unlimited and the focus of the study is so precise that I have a real hard time to understand how meaningful these results can be.
> there may be other lifestyle factors contributing to that lower mortality risk among people who drink coffee, like a healthy diet or a consistent exercise routine.
Yeah no shit. Or like getting 8+ hours of sleep, or winning the genetic lottery, or working at a desk instead of on a construction zone, &c.
If it's all self reported it's kind of garbage to begin with, I know people who think they eat healthy diets, they don't
So, in the abstract, they say they controlled for "lifestyle" but then the researchers are paraphrased in the article as saying "This is an observational study, which means the data cannot conclusively prove that coffee itself lowers the risk of dying; there may be other lifestyle factors contributing to that lower mortality risk among people who drink coffee, like a healthy diet or a consistent exercise routine."
On the one hand I get what they're saying about their own study design, on the other hand, it might be good to get more info about lifestyle vs lifestyle.
That's because 99% of the time when a study says "we found an effect in Y even after we controlled for X" it just means that they included X in their multi-variate regression and error analysis in their study of Y. "controlled for" sounds like it has something to do with ruling out the effect of something from causality, but it doesn't.
That effect size is the very thing that strains credulity. How did we miss it for the centuries we've been drinking coffee? How do I not notice the effect when I vary my coffee intake?
> 171,616 people is a big cohort, mortality is clearly measurable, and the observed effect is really large.
This should be a criteria for posting studies in general - large cohort, controls for every known factor, clearly measurable outcome like all-cause mortality, and large observed effect.
It’s a pattern detected in the UK Biobank dataset. I assume by a study you mean an experiment – it wasn’t one. The dataset is longitudinal, which helps a little, but there’s still a big jump from associations to causal links.
Right. So this is simply beating up some dataset until a news-worthy pattern appears. Add in self-reported and this is more wishful-thinking than it is science.
Did they compare against what the non-coffee drinkers were drinking instead? It's not surprising that coffee is substantially healthier than cola, but is it statistically healthier than tea or water?
I don't know any more about this study than is in the links. The NYT reporter covers some of that, though:
> Scientists don’t know exactly what makes coffee so beneficial, Dr. Goldberg said, but the answer may lie in its antioxidant properties, which can prevent or delay cell damage. Coffee beans contain high amounts of antioxidants, said Beth Czerwony, a registered dietitian at the Cleveland Clinic’s Center for Human Nutrition in Ohio, which can help break down free radicals that cause damage to cells. Over time, a buildup of free radicals can increase inflammation in the body, which can cause plaque formation related to heart disease, she said, so dietitians recommend consuming foods and beverages that are rich in antioxidants.
> There’s also the possibility that coffee drinkers tend to make healthier choices in general. They might opt for a cold brew or a cup of drip coffee instead of a less healthy source of caffeine, like an energy drink or soda, Dr. Goldberg added. “If you’re pounding Mountain Dew or Coca-Cola or Red Bull or all these other drinks, they have tons more sugar, all the artificial stuff — versus coffee, which is a generally unprocessed food.”
(Side note: if someone else read this and started drinking coffee because of it, they'd probably be replacing an existing beverage choice as well. IOW, even if substitution effect was the cause or a contributing factor, people acting on the conclusions may still see the effect – and certainly would at public-health scale.)
As someone who also heavily uses UK Biobank in my research, I would just encourage people to think about this effect size and ask whether it's plausible. If true, coffee has a more powerful effect on your risk of all-cause death than any drug for most diseases. It's wildly implausible. The results are confounded. There is no causal anchor.
Agreed, this doesn't pass the sniff test at all. Makes me think of this article[1]:
> Your estimate will be wrong for a silly, almost tautological reason: if you can only detect large effects, then any effect you detect will be large. If you keep looking for an effect, over and over again, until finally one study gets lucky and sees it, that study will almost necessarily give a wild overestimate of the effect size.
My point is that most drugs don't work this well for your disease, if you are diseased. If this result were mechanistically true, then we could instantly prolong human lifespan dramatically.
But my point is that when you're healthy, the mortality risk is so low, that it doesn't take much to make it even lower.
Even more impressive result, exercise reduces all cause mortality by 40%:
> Using a large nationally representative sample of US adults, we found that those who engaged in both aerobic and muscle strengthening activities consistent with the recommended 2018 physical activity guidelines for Americans showed a reduced risk of all cause mortality (40% reduction).
But that doesn't follow. It's conditional. More accurate follow would be "instantly prolong human lifespan dramatically AS LONG AS YOU DON'T GET DISEASED"
Example: having a fire extinguisher in your house decreases risk of losing your house in a fire by 30% before a fire. But if your house is on fire I bet it's much much lower. There are two different populations, two different distributions.
Luckily, there is no signal for harm from coffee, so we can randomize a bunch of healthy people and see if there is an effect. Personally, I'd want to see a higher quality of evidence before spending my time on it, but if people believe it, this is one of the most important studies in the history of human health waiting to be written.
While it’s closer to speculation than science, past discussion of health benefits from coffee focused on antioxidants. Coffee, green and black tea, and cocoa have relatively high antioxidant content[1], particularly after adjusting for quantity consumed.
I haven’t seen any breakdowns of how the average person ingests antioxidants, but it’s not like everyone eats 3 oz of blueberries a day :-) Beverages might be a major source.
Again, this is pretty close to speculation, but it’s not nothing.
Note that there is a suspected link between anti-oxidants and cancer. The mechanism is pretty simple: oxidative stress is a warning system to the cell that initiates various repair mechanisms, up to apoptosis. Too much anti-oxidants suppress this warning system, thus allowing a damaged cell to go on.
Yours is perfectly fine speculation for a message board. I just think that the result is likely confounded, and there is no reason to reach for a biological mechanism when the study wasn't causal in the first place.
I assume this would fall into the confounding part: culturally we see coffee as a drug that can have adverse effects, and will make efforts to limit its consumption when health deteriorates.
For instance, I would expect people to not drink coffee if they have chronic stomach illness or are under a pretty strict diet, or heavily medicated. This could heavily skew results of how long heavy coffee drinkers tend to live.
As Bayesians, shouldn't this effect size cause us to update in the direction that coffee is good for health, even if we think confounding contributed to the large effect size?
Seems to me that a likely reason for a large effect size is both a causal effect of drinking coffee and confounding, added together.
As an analogy, suppose you and I are talking about a Hollywood star who has made a lot of money. I say: "The star is probably a good actor." You say: "I would just encourage people to think about this wealth level and ask whether it's plausible. The star is probably just physically attractive." Of course, the wealthiest Hollywood stars tend to be both good actors and physically attractive.
Why is a large effect size more plausible for some unspecified confounder than it is for coffee? I think some research suggests coffee induces benefits akin to caloric restriction (autophagy) among other good things: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4111762/ Should we really have a prior that an unspecified confounder can have such a large effect size? How common is that?
>Compared with nonconsumers, consumers of various amounts of unsweetened coffee (>0 to 1.5, >1.5 to 2.5, >2.5 to 3.5, >3.5 to 4.5, and >4.5 drinks/d) had lower risks for all-cause mortality after adjustment for lifestyle, sociodemographic, and clinical factors, with respective hazard ratios of 0.79 (95% CI, 0.70 to 0.90), 0.84 (CI, 0.74 to 0.95), 0.71 (CI, 0.62 to 0.82), 0.71 (CI, 0.60 to 0.84), and 0.77 (CI, 0.65 to 0.91); the respective estimates for consumption of sugar-sweetened coffee were 0.91 (CI, 0.78 to 1.07), 0.69 (CI, 0.57 to 0.84), 0.72 (CI, 0.57 to 0.91), 0.79 (CI, 0.60 to 1.06), and 1.05 (CI, 0.82 to 1.36). The association between artificially sweetened coffee and mortality was less consistent. The association of coffee drinking with mortality from cancer and CVD was largely consistent with that with all-cause mortality. U-shaped associations were also observed for instant, ground, and decaffeinated coffee.
Positive health effects from drinking sugar-sweetened coffee make me think it's not just confounding, since I wouldn't expect health-conscious people to drink sugar-sweetened coffee. But I'm suspicious regarding the "less consistent" association for artificially sweetened coffee. That makes me think that there is just too much noise in the data to know for sure, or perhaps artificial sweeteners are actually bad for you?
> As Bayesians, shouldn't this effect size cause us to update in the direction that coffee is good for health, even if we think confounding contributed to the large effect size?
If you apply this thought process to alcohol (given what we know now), what would you conclude about this approach to updating your priors based on implausible observational data?
Another nutritional epidemiology study with an absurdly large effect size that is almost certainly due to confounding factors.
Yes, the researchers did an admirable job trying to control for confounders. Doesn't matter. Confounding factors for health are impossible to adjust for, whether it's healthy user bias or nutritional choices or a million other possible factors. There's just no way to take this sort of causality seriously when humans are living infinitely complex lives. Stop wasting money and do an RCT.
Also, traditional media is still embarrassingly bad at communicating correlation vs causation. How does this get past a science editorial board.
You can't do RCTs on something as common as coffee consumption.
What you can do is mendelian randomization studies. There are genes which influence bitter taste which seem like obvious candidates: If coffee tastes like pure quinine to you, you're probably drinking less of it than you otherwise would.
A quick search shows that there have been M.R. studies on coffee, and they do suggest the relationships between coffee drinking and various good health outcomes aren't causal, just like the ones on alcohol. At this point, we should be suspicious of any "U-shaped" effect curves of extremely common and popular habits.
Yes, but go to the Cochrane library and try to get sensible analysis on anything that doesn't have a few RCTs under its belt, and Cochrane just shrugs.
>There’s also the possibility that coffee drinkers tend to make healthier choices in general. They might opt for a cold brew or a cup of drip coffee instead of a less healthy source of caffeine, like an energy drink or soda, Dr. Goldberg added. “If you’re pounding Mountain Dew or Coca-Cola or Red Bull or all these other drinks, they have tons more sugar, all the artificial stuff — versus coffee, which is a generally unprocessed food.”
It sounds like we need a study comparing people who rarely drink anything but water vs coffee drinking vs energy drink/soda drinking.
It sounds like they didn't cover lifestyle factors, but I'm wondering if you even could. Over 7 years, does 170,000 participants means people lying or not remembering things properly cancel each other out? or would the data be too muddied to tell.
I'm a habitual coffee drinker and I can tell you with a high degree of certainty that I almost never drink non-diet soda, and haven't for at least 7 years. It's pretty hard to just forget behaviors that are habitual for you.
While true for habits, I eat cake like maybe 3 times a month four months out of the year? I never drink soda, but I couldn’t tell you what my consistent sugar/fat/cholesterol intake is, it varies with the seasons/stress, etc. is it better than average? Worse than average? I dunno. Same with exercise.
Also I'm a no-coffee but energy drink (Bang usually) drinker and my energy drinks have either 0-3 grams of sugar... I drink water all day long, no sodas, etc. I'm sure 280 grams of caffeine can't be that great for me, of course.
I wonder if it's because coffee as an appetite suppressant causes colorific reduction in people - effectively, they eat less. Fasting has recently been proven to also lower mortality risk by a large amount.
> Coffee suppresses your appetite because it contains chlorogenic acids which are a type of phytochemical compounds that help control hunger pangs and suppress your appetite. Because of this, you don’t need to drink caffeinated coffee to integrate it into your weight loss program; decaffeinated coffee will do just fine.
A lot of people that don't drink coffee have heart issues. Even ones that don't know they have those kinds of issues don't drink coffee because it makes them feel bad. It's typically the heart doing uncomfortable things for them.
And since they already have heart issues - ding ding ding. Correlation. It's not that coffee is making people healthier, it's just a substance that is addictive that people that don't have heart issues drink.
- Is sweetened coffee also adding creamer? I don't know of many people who take coffee with sugar but no cream. They usually go together.
- Were coffee preparation methods at all considered? I don't know if everyone in the trial was being served the same coffee or if respondents prepared coffee in whatever manner they liked and just reported how much coffee/how sweet they made it. Different methods may require more or less sweetner, so the guy who takes it black might be e.g. doing a Chemex/pourover, while the guy doing cream and sugar might be going through a standard drip. A third might be doing a French Press. The extractions from those methods will be wildly different.
That's certainly the conclusion I was expecting to read, yet the study found that sweetened coffee drinkers also had a lower mortality rate than the general population (albeit slightly less of an effect than with the unsweetened group).
Yep. Sweeteners have a terrible impact on the body because they produce an insulin response despite not being sugar in your bloodstream needing to be flushed.
> - Were coffee preparation methods at all considered? I don't know if everyone in the trial was being served the same coffee or if respondents prepared coffee in whatever manner they liked and just reported how much coffee/how sweet they made it.
It was not a controlled trial, it's an observational study. They had a few hundred thousand people fill in a questionaire (up to 5 times in different seasons) about their diet (sweetened/unsweetened/type of coffee consumption were only a few of the many questions). They registered the answers and compareed a few years later how many died, with statistical controlls for different observed characteristics between drinkers and non-drinkers.
I do not know if coffee habits in the UK have changed in the past 25 years since I lived there, and I fully expect that they have with the rise of Starbucks and other "gourmet" coffee chains, but a lot of UK coffee consumption was instant coffee granules, at least during the 1980's and 1990's. That would be an interesting piece of data to observe, what kind of coffee were these people drinking? Instant? Ground? Pods?
> Baseline demographic, lifestyle, and dietary data from the UK Biobank were used
This data is from the UK where coffee is still significantly less popular than tea. Would be interesting to see the mortality risk of coffee vs tea drinkers though.
I always wait for my coffee or tea to cool down a bit before drinking it for this very reason. Doesn't make it any less enjoyable, I don't understand how people develop a tolerance to scalding hot and won't even finish anything less. Such a weird cultural preference.
Even better on a hot day is iced coffee! Something about letting it end up at room temperature for a while alters the taste but if it just goes straight on ice it's kinda sweet on its own.
> I don't understand how people develop a tolerance to scalding hot
It's the same as with repeatedly touching hot things with your hands: The nerves deaden and eventually very hot stuff doesn't feel as hot anymore. For your mouth, this is not so handy I feel. I occasionally make mistakes that burn me quite badly, but I can't really tell when it's happening because my memory of a bad burn feels way worse than the reality currently does.
Edit: Actually it's not so handy on your hands either.
Isnt the British method of preparing tea and coffee to load it up with milk and cream immediately? Makes it so you can drink quickly and don’t have to wait for it to cool off.
(Source: am American and have watched one or two YouTube videos of how to prepare tea the British way)
>Isnt the British method of preparing tea and coffee to load it up with milk and cream immediately?
I feel like the potential health risks of doing this every day might be worse than the health risks of cancer caused by exposure to hot liquids, even if it's something as small as a bit of increased weight gain. (Especially since you can just wait for it to cool down a bit.)
The study found natural sweeteners also had a decrease in mortality (but artificial sweeteners did not - but probably because people choosing those already have health risks).
I get the sense after living in a country which produces incredible coffee for a while that it's about quality.
Like they're just covering up the bad taste.
You have to pay like 20$ a bag to get something that isn't bitter in North America. Here if you want bad coffee at a low price I guess you can buy instant?
I don't think green tea drinkers are putting many additives in there.
It definitely varies wildly. Some methods of decaffeination might leave as much as one-third of the coffee still in the beans.
I'm a regular coffee drinker (and not caffeine sensitive), and I do get a placebo boost from decaf, but without any noticeable effects from actual caffeine.
I’ve heard that sometimes ordering decaf will get you a caffeinated drink and that a lot of places disregard or don’t pay enough attention to that particular request. I have no source or any numbers though.
That's a smart thing to do - just ask for hot water at starbucks (if you're out of the house of course) and slip in a decaf tube. It would probably be free.
Yeah I throw up every time I drink coffee. I mean I don’t want to admit it but that’s probably a sign that somethings wrong which is a problem. I saw a doctor today and he said “something something interesting parasympathetic system”.
If you have issues with caffeine, decaffeinated coffee is often off limits as well. Decaffeinated coffee isn't caffeine free coffee. There's a limit to the process.
Also, if you have issues with caffeine and have never drank coffee before, why ever start? It seems like a thing you could just never do and be fine with.
Not to mention, what if the problem isn't with the caffeine, but something else in the coffee. Decaf doesn't fix that.
The latest word is that this is where the previous idea about a cup of wine a day being good for you came from (it's not). Studies pursuing this question generally did not sufficiently control for the fact that people regularly drinking alcohol are in a state of health where they can regularly drink alcohol. It's not as easy to control for as it sounds because somebody might defer for reasons tied to possible health issues, but without even knowing it. Instead, just like you're talking about here simply not liking how it makes them feel.
This is an interesting study. As someone who only drinks sweetened coffee, I will start stirring in some unsweetened coffee in order to get the health benefits.
Perhaps I'm reading the summary of numbers wrong, but it looks like at 1.5-2.5 cups a day, the hazard ratio was 0.69 for sweetened coffee drinkers vs 0.71 for unsweetened coffee at 2.5-4.5 cups a day.
With confidence intervals on those, about the same even if the number of cups is different, but odd that 1.5-2.5 cups per day unsweetened comes out worse than sweetened.
A study described in the Dorito Effect took millions of grocery receipts and analyzed them. Turned out people who had wine in their carts also had an overall healthy selection of food at checkout. The customers who bought beer stuffed their carts with all kinds of junk.
So there is that. So much for "a glass of wine a day is good for your heart".
Another well-documented problem with the "glass of wine good for your heart" studies was that the groups that didn't drink wine usually included teetotalers, who had likely already damaged their bodies in the past with alcohol abuse, and had since sworn off.
I'm bad at reading scientific papers, could someone clarify this please? It says in the results:
> Compared with nonconsumers, consumers of various amounts of unsweetened coffee (>0 to 1.5, >1.5 to 2.5, >2.5 to 3.5, >3.5 to 4.5, and >4.5 drinks/d) had lower risks for all-cause mortality after adjustment for lifestyle, sociodemographic, and clinical factors, with respective hazard ratios of 0.79 (95% CI, 0.70 to 0.90), 0.84 (CI, 0.74 to 0.95), 0.71 (CI, 0.62 to 0.82), 0.71 (CI, 0.60 to 0.84), and 0.77 (CI, 0.65 to 0.91); the respective estimates for consumption of sugar-sweetened coffee were 0.91 (CI, 0.78 to 1.07), 0.69 (CI, 0.57 to 0.84), 0.72 (CI, 0.57 to 0.91), 0.79 (CI, 0.60 to 1.06), and 1.05 (CI, 0.82 to 1.36).
It explicitly says that the all-cause mortality for unsweetened coffee was lower, that's pretty clear. But then it just gives (Confidence Interval?) numbers for "the respective estimates for consumption of sugar-sweetened coffee" but doesn't say if it lowers all-cause mortality, is that implied as well? Or are those numbers just confidence intervals without giving an assessment?
You're not bad at reading science papers, I suspect you have not picked up the techniques to read science papers. Imagine you're staring at a long and complex Bash script. And you don't know Bash but you do understand other programming languages. You understand the shape of what's there, but not the details.
Now also imagine that the self-same Bash script is written in the tersest style possible without any consideration to how accessible it might be for the reader. That's most science papers.
Once you understand how a paper is to be read, and different papers, e.g. medical, or observational (like this study) or computer science, will have differing common styles between them.
So you're not bad at reading science papers. It is simply that nobody bothered to show you the techniques yet.
Correct, ">3.5 to 4.5" / "0.71 (CI, 0.60 to 0.84)" means "we're 95% confident that people who had 3.5 to 4.5 unsweetened coffees per day had 60-84% the risk of mortality of baseline (average 71%)".
There's also a wide range of sugar amounts you can add to coffee. I add only about 1/3 cube of sugar to a cup of coffee to slightly offset the bitterness, where I see other people sometimes toss in 3 cubes (which tastes awful to me).
That's about an order of magnitude difference right there.
> Those who drank 1.5 to 3.5 cups of coffee per day, even with a teaspoon of sugar, were up to 30 percent less likely to die during the study period than those who didn’t drink coffee. Those who drank unsweetened coffee were 16 to 21 percent less likely to die during the study period
Eh? So having sugar in the coffee was better than no sugar? am I reading this wrong?
This effect makes me very curious, because yeah I wouldn't think adding sugar would be better, but one effect could be that - if people are really only using a teaspoon of sugar, maybe people who are able to moderate the sugar intake in coffee are good at moderating diet in other ways as well? I drink black coffee, but, it's not that I'm being healthful, it's I like the dark strong flavor of coffee, and that desire for "strong flavors" means I don't always make the best health choices in other areas.
Yea I thought that was worded a little confusingly as well, or at least my intuition is confusing me versus what was written.
I also wonder if it's just increased consumption of water via coffee that is helpful here. They're saying it's not the caffeine so would it then just be the residue from the beans soaking in the water?
If you've had health (&/or weight) issues it is common to adjust your diet, eg to cut out excess sugar. Making the switch to no sugar in coffee is pretty easy and likely to stick (even if doughnuts come back). If you've never had health issues you keep putting your teaspoon of sugar in your coffee and don't think about it.
I've been a caffeine user for my whole life - started drinking energy drinks as a kid, took caffeine powder/pills in college for studying, drank a lot of coffee at work - and I've stopped about a month ago.
I find that caffeine made me anxious, so much that all the energy wasn't even worth it anymore, as I couldn't focus on anything from anxiety. After stopping, my anxiety has went down so much that I feel I'm able to do much more work then before, even if I'm doing it slower, because I can just relax and focus on what I need to do, without being distracted by every single intrusive thought I have and without the crash that inevitably comes every day after caffeine wears off.
I don't care about "health benefits" of coffee, to be honest. Caffeine is a crappy drug (for me), so nowdays I only save it for situations where I have to stay awake for longer than I usually can.
The study covers this, as does the NYT article. From the article: "The mortality risk remained lower for people who drank both decaffeinated and caffeinated coffee."
I've always had issues with focus, and first year of college was overwhelming. I cut out all unnecessary time sinks, and I've found that I lack enough "focus" in a day - at some point I'd just read, but be unable to engage with any words I'm reading.
Caffeine pills helped me study for longer, however, the tolerance made me take more and more until at some point I was taking up to 2000mg of caffeine a day. I was barely functioning from anxiety, but I managed to be amongst better students on my year.
At work we have an espresso machine, so it's very easy to just "grab a cup" when I feel tired while working on an important task. It wasn't strange for me to drink 5-6 cups per day.
Nowdays, I'm only drinking coffee if it's a social event, and I keep a hard limit of one cup per day.
I recently quit caffeine, too. It is interesting how I was so habituated with the rush of it that I didn't consider the anxiety. Now whenever I consider having some tea I tell myself, "I really want to become extremely anxious" and so far it hasn't been worth it to take any tea after that.
Not to criticize but... I've read so many (abstract of) studies on coffee and tea with such marginal conclusion on all sides that I'm pretty convinced the real state of thing is: at normal consumption level they are nor good nor bad. That's is.
Yes. The claim is that all-cause mortality decreased. So coffee makes it less likely that you died from stroke, heart disease, cancer, infectious disease, Alzheimer's, car accidents, drowning, drug overdoses, natural disasters, suicide, etc..
Crazy to see that Annals of Internal Medicine prominently highlights "metrics" for the article including "Picked up by 215 news outlets." Are academics supposed to be like Buzzfeed writers now, chasing media instead of peer citations or lasting impact in practice?
I drink anywhere between 0-5 cups of black coffee a day. By cup I mean a standard size coffee cup you'd find in any store. Sometimes I'll throw in a cappuccino (double espresso) because I'm feeling like having one. So far I've lived through studies telling me I will live shorter, and studies telling me I will live longer.
There seems to be an unhealthy neurosis/anxiety built up around staving off death as long as possible - the number of articles on HN, companies started around longevity by people who are, to put it bluntly, scared shitless of dying, is disturbing. You can't lower your risk of dying. If enjoy a cup of coffee, then enjoy a damn cup of coffee regardless of what studies say.
Its not so much the dying for me, but losing out on some living because of some poor choices. Im always greatful for the scoop on how to live longer, and your prescription to just not worry about it and enjoy whatever would not work for me, as I'd take too many opiates, smoke, and stop exercising which would shorten and narrow my life.
Of course you can. Moderate exercise unambiguously makes this risk lower. Of course, even with much lower risk today you will eventually die. Perhaps this is what you meant.
Those who drank 1.5 to 3.5 cups of coffee per day, even with a teaspoon of sugar, were up to 30 percent less likely to die during the study period than those who didn’t drink coffee.
I wish coffee studies would report results in ounces (or better, ml) instead of ambiguous "cups"
The Coffee industry uses 6 ounce cups, the USA standard "cup" is 8 ounces, and the imperial cup is 10 ounces (the study was based on UK data).
I drink around 12 oz of coffee a day and I drink it out of a single large coffee cup, is that 1 cup, 2 cups, 1.5 cups, or 1.2 cups?
It is a study on self reported data. They won't know how strong the coffee was, or even the size of the cup. Or if the teaspoons of sugar were heaped or flat.
Curious how well they were able to control for economic factors. How are they not sure it’s not
“People who can afford to buy lots of coffee can also afford other lifestyle ingredients that lead to longer life, relatively.” ?
Latter Day Saints and Adventists don”t drink coffee, and yet they get to brag about better than average longevity too. But that too could just be a canary for economic indicators.
Even if a real causal relation between coffee consumption and longevity was proved, I feel that the benefit of that finding would be limited as long as the actual mechanism isn’t understood. Few people who don’t like drinking coffee will start drinking it because of that, and those who like coffee drink it anyway (they’ll just feel even better doing so, maybe).
The culture around me is to drink black coffee or lattes. No added sugar or cream. Most people in my office space who seem to drink coffee as their hot beverage of choice.
There’s not a lot of chatter about coffee being healthy or unhealthy. The only unhealthy thing that people tend to want to avoid is being unable to sleep due to drinking too much of it or too late.
Another cultural thing is to joke about the first cup of joe being mandatory if you want to wake up properly (at the office). In that light it makes sense to not really consider whether it is healthy or unhealthy; it’s as if your body needs it anyway so you either gotta get it or sleepwalk through the day.
Caffeine is habit forming. If you're in the place where you "have to" have a cup of coffee every morning just to feel OK you can probably get over it after about two weeks of abstinence. Probably the hardest time is the second day.
Habit forming? This is obviously a physical dependence like any other drug. There are thousands of case reports on /r/decaf outlining a recovery period of months and years with horrible side effects like anhedonia, panic attacks, sleep issues, brain fog, cramping. The hardest day is day 2?? You honestly believe that is sufficient payback for the years of being buzzed up and artificially interested in boring and pointless office work by drinking this poison?
> a recovery period of months and years with horrible side effects like anhedonia, panic attacks, sleep issues, brain fog, cramping
These are all anecdotes - I don't believe there is actual evidence for this being the case. With such reports, it is frequently the case that there are other factors that influence this as well (for example, getting off of multiple drugs at once or an external factor that influences quitting, but that also makes you sad). I'm not saying it absolutely can't take a while to feel normal again, but you should take this frankly histrionic type of reporting with a grain of salt.
Given no other type of input, you should expect to be average. On average, it takes a week or two to get over coffee and you may miss it for a while.
Your statement about "years" of coffee drinking is irrelevant. The amount of time you are on a drug has little to do with the amount of time the body needs to achieve homeostasis when you stop taking it.
Not true at all. For every 1 year you can expect 1 month extra to recover fully. Every drug withdrawal group has some variation of this with different figures. An example a guy who watches porn for 2 weeks will have a much shorter reboot than one who watched porn for 24 years. That second guy will go through 2 years of PAWS and has destroyed his hormonal system. Moving away from stimulations to stimulants, Coffee stops blood flowing through specific areas of the brain and increases it flowing through other areas thats why your experience of life changes while on coffee., this is even worse, its a physical drug , but it has also destroyed other types of glands like the adrenals. You are very naive and foolisj to think you can pay back the years of being buzzed up and not experience a depression for a long long time afterwards. You have to repay it all. Its the same for most drugs, weed affects the blood flow through other areas of the brain and long term this can cause irreversable damage.
3 of the top 5 posts of all time on that subreddit as an example are speaking in terms of "915 days caffiene free", "2.5 years caffee free" .. etc. These are the most dramatic and interesting stories shared there but the people there are obviously interested in long term case studies and these stories are popular for a reason. Nobody cares about "2 weeks" there everyone quickly realises this is a long slog to getting back to normal of months and years.
The interesting bit here is it seems even more beneficial to add a little sugar to your coffee. It doesn’t make much sense to me, considering all the negative news about sugar in general.
I drink coffee because it became part of my routine, then I got to enjoy it, and now it helps me focus while working.
One aspect I notice from my caffeine intake is that it helps me deal with stuff in general--nothing stresses me out. The downside is that I also feel positive things less as well, so I try to limit it to morning/mid-afternoon of weekdays. I can certainly see in my case living a life with less stress promoting longevity but with less richness of experience.
I don't think they do. Which is much better than correcting for variables and doing it badly.
Anecdotally, I am the only healthy person I know of in my group who voluntarily uses artificial sweetener. It seems to me that the use of artificial sweetener is strongly associated with health problems such as morbid obesity and diabetes: people who don't have to don't use them.
Regarding artificial sweetener itself being causal there is very little reliable data to support that. There does seem to be a link between Aspartame and (bladder) cancer but it has so far only been shown in animal models.
> It seems to me that the use of artificial sweetener is strongly associated with health problems such as morbid obesity and diabetes
Yeah. Cause and effect seems to be reversed here. I started using sweeteners because of my coffee consumption and watching the effect it was having on teeth. Later on cut the sweeteners completely, just because they don't taste as good as actual sugar, so why bother.
I don't think most are as bad as some people believe. A lot of it has probably to do with the notion that they are 'artificial'.
Well, no more so than pure sugar. Go chew on some sugar cane if you want something more "natural" :) Even that must be done in moderation.
I've cut down coffee intake by a lot, but still have a little bit.
For those of you that have quit completely - does the roller coaster stop? By that I mean... you have caffeine, feel productive, caffeine wears off, you feel unproductive, rinse and repeat.
Are you over all more productive or do the peaks and valleys just average out into nothing?
I have a weird habit of quitting for 6-12 months and then resuming drinking it. I've done so twice now (once when I was a bit younger, and the second time recently) and my impression is that overall everything is better when I do drink it. It tastes nice, the effects are nice and if you don't overdo it (i.e. increase your consumption above a normal threshold, like a small cup per day) it stays pretty nice forever. But this is just the case for me - I've heard plenty of people say that without coffee their life is better on average (more focus on average throughout the day).
tl;dr: Overall more productive. It's also more pleasurable.
> The mortality risk remained lower for people who drank both decaffeinated and caffeinated coffee.
Very interesting! I've seen this conclusion many times in the past decade+ but have yet for someone to call out the aspect of caffeine. I wouldn't suspect caffeine to result in lower mortality risk, but you never know
I forget the details, but a different study in recent years found that decaf and caffeinated did have different links. IIRC it was measuring both cancer rates and heart disease, and found positive correlation with both reduced for caffeinated coffee but only one for decaffeinated. And years before that, a study that found positive correlations with caffeinated coffee, but not straight caffeine, and not decaffeinated coffee, which indicated some sort of interaction with the coffee compounds and the caffeine in particular (very fuzzy on this one).
> The association between artificially sweetened coffee and mortality was less consistent.
Also, is unsweetened coffee black coffee, or could it be coffee + some type of creamer? I’m assuming it must be the latter because if they meant black coffee they would have said that.
>I’m assuming it must be the latter because if they meant black coffee they would have said that.
The authors seem to have Chinese names, a country with extremely low dairy consumption, so I wouldn't assume that. I'm from south america and never seen a coffee with creamer, had to look up what that means.
> I'm from south america and never seen a coffee with creamer, had to look up what that means.
I didn’t know what else to call it. It’s typically dairy or a dairy substitute but I’m also thinking of things like steamed milk in a latte, flat white, or cappuccino (those are global, no?).
What if people who drink coffee get more done, people who get more done are more fulfilled, and people who are more fulfilled live longer?
Edit: doesn't explain that the effect also worked with decaf. Maybe coffee contains other compounds and secondary metabolites which have health benefits
Quick Theory: The regular coffee drinkers are (on average) folks with more energy/time/money (which keeping up a coffee habit requires), or working (free & convenient coffee at the office), or other things that correlate with better physical & mental health.
> there may be other lifestyle factors contributing to that lower mortality risk among people who drink coffee, like a healthy diet or a consistent exercise routine
That must be for people who hate coffee, or hate themselves, or both. Even the cheapest grocery store brand ground coffee that comes in buckets sells for $0.4/oz which is about twice the price you mentioned. Anything worth drinking costs $1/oz where I live.
I’ll have a guess at the causation here: more coffee consumed => better code written => higher income => higher standard of living, correlated with better health outcomes.
People can argue about the design of the study all they want, but 170k people followed over 7 years is enough evidence for me that drinking black coffee is beneficial to my health.
Alternative interpretation: neither the coffee nor the caffeine is helpful.
Instead, coffee consumption is so pervasive that coffee drinkers are “normal” and many people that don’t consume coffee do so because it’s actually hurtful or uncomfortable … and that likely correlates to other weaknesses.
The same interpretation should be considered for all of those moderate drinking studies… I am quite certain nobody is getting a health benefit from alcohol.
> the data cannot conclusively prove that coffee itself lowers the risk of dying; there may be other lifestyle factors contributing to that lower mortality risk among people who drink coffee, like a healthy diet or a consistent exercise routine
...and controlled for in the study
> lifestyle, sociodemographic, and clinical factors
I would just caution people to understand that saying that something is "controlled for" in an observational study (which is something I do all the time, I'm not saying it's bad) is not the same as saying that we've eliminated confounders, leaving a causal effect.
Seems ridiculous to assume there aren't any health benefits from at least some types of alcohols at some levels of consumption. Just because the ill effects are better documented doesn't preclude the existence of benefits.
For the common person, the potential health benefits do not outweigh the potential damage -- especially when there are other ways to get the same health benefits with less risk. At least, that is the stance I believe the medical community has adopted.
yeah but just from mechanisms.. small organic solvent molecules aren't like, a promising target for antiaging treatments.. most solvents are bad for you, for obvious reasons, that is, they interfere with cellular chemistry and they have to be metabolized by the liver in large quantities. seems ridiculous to think alcohol would have any positive effects-- as a drug, it's just so shitty. I mean, you have to take 20g+ to get a physiological effect. The whole experience of having it in your system is dominated by the processes trying to get it /out/ of your system!
Folks who drink alcohol should consider taking safer and more powerful drugs.
Bah. I try to limit myself to a 6 pack a week, well under guidelines, but alcohol doesn't have a dramatically bad effect on mortality until you're in the 20 drink / week range.
I don't think alcohol is somehow better than anything else, but I don't think it's that harmful either until you get well beyond the 14d / wk max recommendation.
There are plenty of other factors like meat consumption and exercise habits that have a bigger effect. I'm not giving up one harmless vice for an infinitesimal benefit. We're all going to die of something.
> The whole experience of having it in your system is dominated by the processes trying to get it /out/ of your system!
That is not exclusive to alcohol though. I am not extremely drug-savvy, but I do believe this is true for psilocybin mushrooms and a few other hallucinogenic plants/fungi.
> Folks who drink alcohol should consider taking safer and more powerful drugs.
This is often an issue with legality and sourcing for many, not to mention the cultural acceptance of alcohol by many cultures.
No, if coffee bothers your digestive system, you don't drink it. The reason it bothers your digestive system is you have other health problems that are undiagnosed/medicine doesn't understand yet. Those other health problems could contribute significantly to all cause mortality.
In fact, it says that decaf coffee also has that association, so that would mean it's not the caffeine.
It also says they don't make the same conclusion about artificially sweetened coffee (the study says it's "less consistent"—seems I need to pass the paywall to see the numbers on that). One wonders if they believe that the artificial sweeteners are killing people, or that they interfere with the benefits of coffee, or if they'd say this reveals that selection effects are strong here.
Bummer, I'm in my fifties now and used to love coffee but now I just don't really enjoy it that much. Mostly switched to tea, is there a study that tea is even better?
Hm, well actually, since someone posted the PDF above, seems you're right.
Decaf did quite well (although perhaps noisier due to smaller sample size).
I do wonder about some of those error bars and controls though. For example artificially sweetened coffee decaffinated at 1.5-2.5 cups per day seems to have a higher rate of death (1.11) - but artifically sweetened decaffinated at 3.5-4.5 cups has half the rate of death (0.52). By contrast black decaf at 3.5-4.5 per day does worse than that (0.66).
Anyway, if there's any significance to this, you're right that caffeine does not seem to play into it much in their stats.
I had the same thought. "Coffee is the Fountain of Youth" is not what they meant, eh? :) (Although I often joke that you can actually see me turn from a zombie into a live human being with that first sip in the morning.)
On another note, I always break sugar cubes in half and even a half is sometimes too much. I don't understand how people can drink coffee with 1 or even 2 cubes.
Yes, if you are having sleep problems they might tell you to cut back on coffee and other caffeine sources. Some people are particularly sensitive to caffeine and get jitters and have trouble sleeping. Most people do not have this problem and as long as they don’t drink coffee late in the day, it does not cause sleep problems.
These studies are known for excluding unhealthy people, especially those with heart conditions.
Edit: by "these studies", I mean caffeine, cigarettes/smoking, alcohol, coffee and generally any food or "health" study. If you don't know the exact make up of the test group, then I just assume it's rigged to get a certain result.
What is "These studies"? Are you referring to all studies? All observational studies? Something else?
While I can't debate "These studies" without knowing what you're referring to, this specific study provides a clear explanation of the study cohort and there's no sign that anyone was excluded or otherwise cherry-picked.
I updated my comment, I realize I was definitely vague in my criticism.
I've found that digging deeper into studies in the past that they would leave out people with heart conditions (specifically with caffeine studies) and not state that _anywhere_ in documentation. And this only came out from investigations.
Studies I've read in the past have claimed the same thing, yet still excluded people that would skew their results without reporting it.
I have a friend who does statistical analysis for a living, and we have a game where he points out the flaws that are only obvious to those that know statistics and research well, and us laymen are oblivious.
A medical doctor once told me "coffee must be good for you because I drink it!". It seems common that people just want science to agree with them, and they don't care how or why.
I can't prove my point on this article (not enough time/energy/will) but I have watched health articles for years and you can go back to news sites and find this same exact study done over and over, reported in news organizations as if it's new every time.
One stupid example, articles from just CNN going back to 2010 just on one page of search results:
Black coffee, even with a teaspoon or sugar has to be better than soda or the sugary monstrosities from Starbucks that are excluded from the study.
One can of coke contains 39g (~7 teaspoons) of sugar. This study seems to be less about the benefits of coffee but rather the health risks of sugar.
> This study seems to be less about the benefits of coffee but rather the health risks of sugar.
The control was not drinking coffee, and far lower all-cause mortality was observed in both black coffee and coffee with a tiny bit of sugar.
Or: Yes, adding a ton of sugar to anything is unhealthy, but this study provides far more information than that. Although it's observational, the observed effect is huge. From the study:
"Compared with nonconsumers, consumers of various amounts of unsweetened coffee (>0 to 1.5, >1.5 to 2.5, >2.5 to 3.5, >3.5 to 4.5, and >4.5 drinks/d) had lower risks for all-cause mortality after adjustment for lifestyle, sociodemographic, and clinical factors," [then repeats for lightly sugar-sweetened coffee, but not artificially-sweetened coffee].
"Nonconsumers" didn't factor soda drinking, energy drinking, etc. So it lumped people who were drinking larges amounts of sugar with people drinking little sugar(tea, water), and compared them to coffee drinkers, which are low to moderate amounts of sugar.
Coffee-flavored milkshakes / cups of syrup and foam and whipped cream and caramel.
They serve coffee also.
If you google 'starbucks unhealthiest drinks', you'll find references to stuff like 'cinnamon roll frappucino blended coffee' which apparently had 85 grams of sugar in its largest size and 510 calories. If you're familiar with the 'packets' of sugar people sometimes sweeten coffee or tea with, 85 grams is like 20 packets. The 'sweetened cup of coffee' referenced in the study referred to a coffee with about 5 grams of sugar added.
No one is forcing you to order a frappuccino. You do realize you can get drip coffee (actually pretty good) and espresso drinks without added sugar there, right?
I didn't take up coffee drinking until my late-20's. At first I took my coffee black, then I read how caffeine boosts the metabolism. This draws down sugar from the blood. To avoid a cortisol response, it's best to complement the caffeine in coffee with sugar.
This study seems to confirm that fake sugar is harmful. I have family who drink fake-sugar cola products - these don't help their weight. I've seen one person fall apart 'mentally' within 1/2 hour of drinking an electrolyte beverage made with sucralose and other fake sugar.
Ideally glucose is consumed with potassium, to avoid insulin release: milk, orange juice, potatoes, etc... Fructose does not stimulate the release of insulin.
"electrolyte beverages", e.g. gatorade, are generally not caffeinated. Why would somebody fall apart after drinking one without sugar? It's basically just water with food coloring and a bit of sodium and potassium.
Also, I've been taking caffeine pills for the better part of a decade, often on an empty stomach. There's no crash from the absence of sugar, the only sort of crash I get occurs a few days after each time I try to quit the stuff.
And before someone asks "But what if it's .. instead?": Yes, they controlled for lots of things:
> lower risks for all-cause mortality after adjustment for lifestyle, sociodemographic, and clinical factors
The patient data is from UK Biobank, which has quite a bit about each participant. While they can't control for everything (like factors that aren't documented), they can control for a lot - probably including whatever possible confounder someone jumps to.
Although it's still subject to the limitations of an observational study, 171,616 people is a big cohort, mortality is clearly measurable, and the observed effect is really large. It's worth paying attention to.