Higher coffee intake may be linked to lower prostate cancer risk | Hacker News Reader

Higher coffee intake may be linked to lower prostate cancer risk

bmj.com

39 pointsrustoo39 comments

What is the value of such weak claims, other than possibly stimulating a research entity to execute a rigorous experiment? Or as marketing fluff for companies that would benefit from making such claims? Or confirmation bias for those of us who suspect we drink too much coffee?

Words like 'may be' (the information is not conclusive)

and 'linked' (we don't know if it's causal)

make this (in my view) un-newsworthy.

There is an important role for research that sets up further research. Without these exploratory studies, it is difficult to determine where to make a larger investment in a more rigorous study.

You'll note that most papers are rather explicit about this, though this is often underplayed by journalists. The article does say this:

> Further research is still warranted to explore the underlying mechanisms and active compounds in coffee.

> If the association is further proved to be a causal effect, men might be encouraged to increase their coffee consumption to potentially decrease the risk of prostate cancer.”

Exactly this. Science/research is largely incremental.

Despite us knowing that correlation does not equal causation for forever, these weak studies keep getting funded and popping up.

The only finding you could make with such a study is to disprove something. If the hypothesis was that coffee prevented cancer, and you found no correlation between coffee and cancer, then that would _disprove_ the claim.

I understand the common person being sucked into these alluring study titles, but it's disappointing that scientists keep producing this kind of empty work.

I try not to shun incremental research because I understand there is value in it. Unfortunately, a large portion of it is frankly very uninteresting and these 'may be' sort of weak links are a necessity to continue research and progress by appeasing the purseholders.

Often these sort of results are picked up by journalists and overemphasized but there are inherent pressures for researchers, their supervisors, and everything up the finance food chain to do the same sort of marketing as well. You have to make sure the people who pay the bills have some sort of progress report that shows improvement and ROI.

The current way of coping with this pressure is showing small promising incremental updates on low risk studies regularly and then doing the interesting research with any slack time you have to hopefully discover the next real breakthrough or leap. Breakthroughs are often non-incremental and are the real allure of research and science, at least to me.

Unfortunately, society doesn't like seeing big risks taken, resources spent, and little to show beyond the, still quite valuable, knowledge of "this didn't work." The vast majority of researchers hate small incremental research and much prefer to use their creativity to take larger incremental leaps or even paradigm/perspective shifting leaps. If we want to stay ahead of the world in terms of research we need to be willing to take bigger risks and accept failure on those risks. Scientific progress is largely at the mercy of the business and economic culture it's conducted within.

I would guess they crop up repeatedly because they are cheap to fund. Fewer funders who want to put a bunch of money and time into a long, expensive study that may produce nothing. Instead fund 10 cheap studies that might produce a headline :(

Publication, future citations, and career advancement.

I agree, and that seems to be the majority of science-related content here on HN.

Shut up and let me enjoy my sixth cup of coffee.

;)

Sadly we have to suffer with articles like this until the coming paradigm shift to better publishers.

I recently downloaded my Ancestry.com DNA data, and started looking at it with the help of SNPedia:

https://www.SNPedia.com

One of the neat things I found is that I have genetic markers for increased coffee consumption:

https://www.snpedia.com/index.php/Coffee

I drink at least a few cups a day and so does my dad, so confirmation bias does the rest.

That makes me wonder if drinking coffee (amoungst other foods) is truly causal in decreasing prostate cancer, as opposed to heavy coffee drinkers having other correlated biomarkers (in particular ethnic correlations) that help dodge it.

Anyways, I’m not trying to disparage this study, I just think it’s neat that we’re somewhat predisposed to like certain foods from birth.

How are you identifying your genetic variants in the DNA data? I'm still learning how to do that, so any pointers are appreciated.

SNPedia has a paid service that can do it for you:

https://promethease.com/

I personally didn’t trust them with my data so instead you can just search for specific SNPs from your DNA file. For example, the coffee one is this one:

https://www.snpedia.com/index.php/Rs2472297

So you search your dna file for rs2472297 and then check which combination you have, e.g., you see “C T” which is slightly associated with coffee consumption. You can probably write or find a script that does this for you.

I've been wondering lately whether decaf provides any of the supposed health benefits that some have attributed to regular coffee.

In at least some cases, the answer appears to be "yes":

https://www.sciencedirect.com/science/article/pii/S019701861...

https://www.tandfonline.com/doi/full/10.1080/10408398.2018.1...

But not in all cases:

https://content.iospress.com/articles/journal-of-alzheimers-...

I've wondered the same, and personally, I'm just assuming the health benefits come from B vitamins, antioxidants, etc, which would suggest decaf should also be beneficial.

Heck the benefit may come simply from the fact that the alternative to coffee for many people is soda pop.

Fantastic point, that's certainly the role it's played in my life!

There are antioxidants in coffee, which I have read previously are suggested as potentially reducing cancer risk by mopping up oxidative molecules in your body. When it comes to the colon cancer risk reduction, caffeine may have a role by increasing the rate at which food moves through the intestines, basically washing out waste faster that would otherwise interact with the cells in the lining of the colon to cause cancer.

Here's a way to interpret data:

Chad drinks 0 coffees per day - he is a surfing instructor and has sex with a different girl every day. Sooner or later he gets some virus that causes cancer.

Bob, the computer programmer, has a stressful job and drinks 10 coffees per day. No sex. This means no human papiloma virus that later causes prostate cancer.

Does coffee have anything to do with HPV? Not really..

Good. One of the more common types of cancer, although next week it will be the #3 cause https://www.mayoclinic.org/diseases-conditions/prostate-canc...

> Each additional daily cup of the brew was associated with a reduction in relative risk of nearly 1%, the findings indicate.

This feels like a reference to that Futurama episode where Fry drinks 100 cups of coffee

https://imgur.com/gallery/uoKqLRm

The study doesn't mention caffeine, but I'm curious if it's a factor.

Caffeinated drinks make me need to pee more often than non-caffeinated drinks. I'm curious if that reduces the amount of time that the bladder cells are exposed to oxidative stress from urine.

Here are a couple of papers about supposed mechanisms:

Regarding caffeine: https://pubmed.ncbi.nlm.nih.gov/16709440/

Regarding coffee polyphenols: https://pubmed.ncbi.nlm.nih.gov/16709440/

> Each additional daily cup associated with reduction in risk of nearly 1%

lol. okay. This presents the relationship as if it's a linear function without an upper bound or diminishing return, which seems suspect. I doubt that. [1]

More holistically speaking, let's approach this with some skepticism. Did they control for wealth? Is coffee predominantly consumed by people with better access to healthcare and who can afford better medical treatment? A priori, I would believe that is generally the case.

Maybe they should specifically study the relationship between coffee consumption and prostate cancer in relatively lower income populations that still drink a lot of it, like truckers.

__________

1. Though I would believe their analysis technically indicates it, especially if they only did the bare minimum of statistical work and simply tested for a linear relationship...

Countless studies have shown coffee consumption to be beneficial to human health, often topping out at some ridiculous amount of consumption (i.e. benefits go right up to 6-8 cups/day), including the many studies that look at what I myself really care about, all cause mortality.

At some point "skepticism" becomes denial.

Here is an example study: https://pubmed.ncbi.nlm.nih.gov/31055709/. I could link them all day.

Key except: "An inverse association between coffee consumption and all-cause mortality was maintained irrespective of age, overweight status, alcohol drinking, smoking status, and caffeine content of coffee."

Most studies do in fact attempt to control for the types of factors you mention.

Did this particular study control for that, is what I asked, because this particular study is what's on the front page of HN.

Also, "countless" studies have shown negative correlations between coffee and human health. [1] So which is it? Oh no, it looks like coffee is also positively linked with coronary heart disease and Parkinson's!

This is an area which benefits from more skepticism. Don't write off skepticism in an area filled with reproducibility issues and bad statistics as "denial".

1. https://scholar.google.com/scholar?hl=en&as_sdt=0%2C33&q=cof...

> Did this particular study control for that, is what I asked, because this particular study is what's on the front page of HN.

Where it or not it did, your comment certainly didn't add any useful information. Perhaps read the study and declare whether they control for the aspects you are concerned about? Bearing-less skepticism adds no value.

> Also, "countless" studies have shown negative correlations between coffee and human health.

I have never seen a study with negative correlation all-cause-mortality for coffee consumption. I'm sure one could exist, but it's a topic I've looked into a good bit, and I think it's pretty fair to stay the evidence for coffee overwhelms that against.

Funny enough, in your less-than-clever search on google scholar for "coffee disease", *literally* the first hit results reads:

"During follow-up, 102 men were identified as having PD. Age-adjusted incidence of PD declined consistently with increased amounts of coffee intake, from 10.4 per 10,000 person-years in men who drank no coffee to 1.9 per 10,000 person-years in men who drank at least 28 oz/d (P<.001 for trend)..."

Gee, in this study, which you apparently linked to support the idea that there are studies that imply negative health consequences associated with coffee consumption, coffee seems to be associated with a fivefold reduction in risk for Parkinson's Disease!

Did you really assume that any hit with both "coffee" and "disease" in it necessarily must be a study that concluded that coffee caused a disease?

And the one for coronary disease? What do you find for that one? How about all the other studies positively linking coffee to diseases? I admit your assessment of the Parkinson's study is correct, but that doesn't really detract from my overall point. You moved the goalposts by changing the bar to all-cause mortality. I think my broader point stands.

> And the one for coronary disease?

"Total coffee consumption was not associated with an increased risk of coronary heart disease or stroke." Are you even trying here?

> but that doesn't really detract from my overall point

Would anything? It is looking to me that, in your mind, nothing would detract from your overall point. That, to your self, your ideas are inviolate. Which is my overall point, and which our continued discussion has only strengthened.

> all-cause mortality

My very first comment referenced all-cause mortality, and I have be consistent this entire time. It's quite O.K. to have goal posts, and I haven't moved them at all.

> I think my broader point stands.

I'll take "I'm right because I say I'm right even though I'm wrong for $1000 Alex". I mean you didn't even blink when your link that you provided supported my point rather than yours? I don't get how you didn't pause for even a second to think "What if I'm the one wrong here?".

My father, who died in 2014 from Metastatic Prostate Cancer, would always nag me and tell me I drank too much coffee!

That being said, the connection here seems weak. Still, I won't feel bad about my coffee habit.

Tangent, but I'm sorry about your father.

I used to drink approx 5 cups of black a day... but now it messes with my digestive processes.

I'm off coffee completely. Black Tea works just fine for caffeine.

Basically every single medical submission is shot down as shoddy research. Maybe we need a separate site than Hacker News for medical research stories?

There is a lot of shoddy medical research. Particularly when it comes to supplements, food intake, etc. You have to realize that there are a lot of vested interests. The coffee industry is massive, and they would have you believe that coffee is a panacea. The first question to ask is: who funded this research?

Why? The research will continue to be shoddy no matter where it’s posted.

At this point I don’t know what isn’t linked to coffee

We know frequent ejaculation lowers prostate cancer risk,[0] and heightened stress levels increases how attractive we perceive others to be.[1] Could coffee be inducing stress that leads to increased sexual activity?

[0] https://www.health.harvard.edu/mens-health/ejaculation_frequ... [1] https://www.fpce.uc.pt/niips/novoplano/ps1/documentos/dutton...

Who is "we"? If you had maybe five other studies replicating that second result about stress and sexuality from the past 20 years, I might find it credible. I don't find one study on this topic from 1974 credible enough to believe it.

It's an offhand suggestive hypothesis made in good faith on an open message board to spur debate.

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