Higher Mushroom Consumption Associated with Lower Cancer Risk | Hacker News Reader

Higher Mushroom Consumption Associated with Lower Cancer Risk

sciencedirect.com

83 pointsanjel46 comments

I understand an observational study is the best you can get, but self-selection on mushroom consumption seems an impossible to correct variable. My stereotypes would expect elevated-mushroom eaters to consume more raw food, salads, etc.

I think I remember study that compared the population in mushroom growing regions of Japan with other regions that didn't grow or eat as many mushrooms. I think they showed a similar result in cancer risk reduction, especially for the farming families with the highest consumption.

There are also studies that show the possible mechanisms behind the effect. One is PSK (used in Japan and originally isolated from shiitake) and another is turkey tail. Both are used to treat cancer by improving immune response in conjunction with other treatments.

I eat cooked mushrooms with nearly every dinner. Definitely don't have much in terms of raw foods and rarely eat salad.

Could still mean you eat less red meat and/or processed meats for dinner? Also talking about populations and trends

You cook your own meals, which is unfortunately a huge step above many many people.

Also probably spend more time outdoors/hiking

A month or two after I started drinking a Reishi mushroom powder tea every morning, a decades-old chickpea-sized lump on my calf I'd long accepted I'd take to the grave with me completely disappeared. There's now a divot left behind where it used to be, covered by the brown patch of skin that slowly developed throughout the years.

Totally unscientific anecdata. It's just the introduction of Reishi tea that was the obvious new variable I could correlate with the change trying to understand why this happened. When I searched "reishi tumor" on google there were piles of results... shrug

Here's a photo of the divot, still surprised this thing is gone, almost had it surgically removed when it first appeared in my 20s:

https://pengaru.com/~vc/tmp/reishi-turns-lump-to-divot.jpg

I would like to see alongside the results of all corresponding "Higher X Consumption Associated with Lower Cancer" metastudies, where X is every other healthy food infatuation over the ages (Vitamic C, Mediterranean diet, Spinach, Broccoli etc).

For sure there might be some benefit for some types of cancer or other diseases, but the constant barrage of marginal results about different food categories does not help create confidence.

Somewhere in the background there is a hugely profitable supplements industry with dubious impact.

It's self-reinforcing. Because there is a subset of the population that reads health news and acts on it, they both:

A: exercise, sleep 8 hours, avoid ultra-processed foods

B: take whatever the latest anti-cancer fad supplement is

Behavior A actually helps, while B is probably neutral. But studies will show that all the B behaviors will be associated with lower cancer risk, because they're also associated with A behaviors.

So this entire class of studies (looking for associations between foods and health) is complete crap.

Unless you control for other variables which isn't outlandishly unlikely in a scientific study

There's also the look-elsewhere effect[1][2] to contend with.

[1]: https://xkcd.com/882/

[2]: https://en.wikipedia.org/wiki/Look-elsewhere_effect

I still wonder what Paul Stamets was alluding to about crimini mushrooms and cancer risk on his episode of the Joe Rogan podcast where he seemed unable to talk freely

As per reddit, so take it with a grain of redd salt:

"What he doesn't want to say out loud in plain English is that agaratine containing mushrooms LIKE PORTABELLOS when consumed RAW are highly CARCINOGENIC while some compounds in white button mushrooms can help prevent and treat breast cancers agaratines can cause cancer, they are heat unstable so if cooked it's not a big risk but raw like they are served often in salads really could be causing cancer. If someone like Stamets came out and said that point blank he could be sued for making radical claims..." [0] Its reddit though and far less hand wavy for the reddit poster to also note agaratine also degrades rapidly when stored and is only theorized to be carcinogenic, the proof of which remains to be shown.[1]

[0]https://www.reddit.com/r/mycology/comments/qm3dag/can_anybod...

[1]Schulzová, V.; Hajslová, J.; Peroutka, R.; Gry, J.; Andersson, H. C. (2002). "Influence of storage and household processing on the agaritine content of the cultivated Agaricus mushroom". Food Additives and Contaminants. 19 (9): 853–62. doi:10.1080/02652030210156340. PMID 12396396. S2CID 23953741. (https://sci-hub.se/10.1080/02652030210156340)

In general, the rule of thumb is to never eat any mushrooms raw. But there are a few exceptions, including button mushrooms. I won't eat raw mushrooms, except maybe truffles (if you really cook truffles then what's the point?).

I think you mean button mushrooms are no exception.

They are a common exception. I wouldn't eat them raw though.

Portabellos and button mushrooms are the same damn thing.

And they are both currently, wide spread exceptions. Food safety bodies do not require them to be cook, their raw use is widespread, some mushroom experts still say it is ok, etc. The status quo has not yet changed.

> "... If someone like Stamets came out and said that point blank he could be sued for making radical claims..."

By... who? The mushrooms, for libel?

(Also, what on earth is going on with r/mycology? Impressive amount of conspiracy theory nonsense voted up there.)

As the reddit comments state, "big portabello." Mushroom farming is a big business, even for Stametz, and widespread, predictably alarmist media coverage about the yes but no nature of carcinogens in criminis wouldn't be good for business. So he did a less than optimal job of steering clear of the issue on Rogancast. And everyone picked up on it, except for news media, so far...

I mean, scientists, public commentators, regulators have been calling out agribusiness over tobacco, sugar, meat, alcohol for over a century at this point. It slightly stretches credibility to imagine that someone complaining about mushrooms on a podcast would be the breaking point.

Paul Stamets is a great story teller, but he’s regarded as a quack among the scientific community. Going on Joe Rogan and alluding to some conspiracy that would bring him harm for warning people of the truth about eating mushrooms is particularly silly, because in doing so he communicated the warning he supposedly had to hide. Are we supposed to believe the conspirators they would harm him are okay with him telling everyone to avoid portabello mushrooms as long as he doesn’t reveal why?

Well, hopefully my not smoking will help cancel out my refusing to ever eat a mushroom.

Even champignons? Chanterelle?

I said what I said.

I really don't understand why people would read your comment and recommend you eat mushrooms. I'd suggest smoking them, for a laugh, but geez. When an adult says they don't eat a thing, leave them be.

I know, it seems weird. But there are people who don’t eat plants, and people who don’t eat any meat, so not eating any fungus makes about as much sense.

That’s too bad. Is it the texture you don’t like? I know a lot of people don’t like mushrooms. I love them!

A good cream of wild mushroom soup with some crusty bread is one of the best meals on a damp, chilly autumn day! Drizzle some extra virgin olive oil over the soup! That is just heaven in a bowl!

I read the headline and immediately thought of ways I’d could sneak mushrooms past my mushroom-disliking child.

For him it’s the texture, so we might be looking at some cream of mushroom soup.

My toddler doesn't like mushrooms — except on pizza. I think it's partly the texture, and partly because it's masked by the rest of the pizza flavor.

I learned to love them. I always liked the taste so I either mashed them or didn't eat the mushrooms itself in a sauce. With time I learned to like the texture as well.

Except Champignons which I still dislike. They have the worst texture of nearly all food I ever tried.

So maybe also try avoiding Champignons

Isn't "champignon" just French for "mushroom"?

Honestly, a great deal of that texture can be hidden simply by chopping them small and adding them to meals that have bits of a similar size.

Some homemade vegetarian meat substitutes are mostly lentils and finely chopped mushrooms. I've seen it for a burger, "meatballs", taco filling, and one that I make is a sausage roll - I just use the filling in bread dough.

You can also hide texture by adding them to ground meats that you are using in other things. Sauces also hide texture and you can add them to a variety of soups.

Got a good recipe to share?

https://www.youtube.com/watch?v=5qRexHDwfds

Unreal good.

Cheers!

Me and my SO love a creamy chanterelle sauce to chicken breasts and roasted potatoes. We often add pan fried cremini mushrooms alongside, so darn good!

And in "wild" stews, ie with elk, deer or similar meat, forest mushrooms is a must.

We use mushrooms in other dishes too, but the above are our favorites.

HN may need another rule against posting "associated with"/correlation studies. Most are just publish-or-perish padding. Studies that show causal links are more rare but more meaningful.

Could someone help me understand how to interpret this line:

> Higher mushroom consumption was associated with lower risk of total cancer (pooled RR for the highest compared with the lowest consumption groups: 0.66; 95% CI: 0.55, 0.78; n = 17)

Specifically the “0.66; 95% CI: 0.55, 0.78; n = 17” line?

ChatGPT told me:

> The “pooled RR” of 0.66 indicates that the risk of cancer was 34% lower in the group with the highest mushroom consumption compared to the group with the lowest consumption. The “95% CI” represents the confidence interval, indicating the range within which the true risk reduction is likely to fall. In this case, it’s between 0.55 and 0.78. “n = 17” likely refers to the number of studies or datasets included in the analysis.

Is that accurate? The top line conclusion of this study was that eating more mushrooms was associated with a 34% reduction of risk of all cancers?

IANA statistician, but yes I believe that's correct.

The confidence interval means that it might not actually be 0.66, sample size n = only 17 after all, but (with 95% certainty) the true value for the population sampled lies within 0.55-0.78.

(threading along for a minor nitpick on above post)

Ya, correct enough.

> > Higher mushroom consumption was associated with lower risk of total cancer (pooled RR for the highest compared with the lowest consumption groups: 0.66; 95% CI: 0.55, 0.78; n = 17)

> Specifically the “0.66; 95% CI: 0.55, 0.78; n = 17” line?

For a given study with a cohort of A entities, and a count of events A_event, and a cohort of B entities, with count of events B_event; the A_risk will be A_event/A, B_risk will be B_event/B; and the risk ratio (RR) between the cohorts will be RR = A_risk/B_risk. [wiki gives a cursory math explainer: https://en.wikipedia.org/wiki/Relative_risk#Numerical_exampl...] If the RR here is lower than 1, whatever distinguishes cohort A from B is interpreted as reducing the risk.

The linked study does a systematic review of the literature. From that review, they ultimately find 17 studies which are suitably comparable under their criteria. Each of these 17 studies are observational studies over different sizes of cohorts (table 1 in linked paper characterizes the n for each study) that report their own risk ratios (figure 3 in the paper plots each of those RR), then they pooled those risk ratios with a random effects model to synthesize each of the different risk ratios between those studies into the single pooled RR within some confidence interval quoted above. ("pooled" because it's pooling the results from multiple studies.)

>sample size n = only 17 after all

The nitpick is that n=17 is referring to the number of papers pooled, not the population sampled in the underlying observational studies. (that number is higher than 17; lee et al in table 1/ fig 3 is n=112,991).

This chapter in "Doing Meta-analysis in R" gives a rundown on the mechanics of pooling effect sizes with random-effects models (as done in this paper): https://bookdown.org/MathiasHarrer/Doing_Meta_Analysis_in_R/...

Odds Ratios and Risk Ratios pop up in a lot of medical studies, there's a number of papers that can help clarify their differences and pitfalls (Viera here is a reasonable entry point: https://sma.org/southern-medical-journal/article/odds-ratios...)

Hope that helps ^_^

Oh god, this is terribly difficult to rid of hidden variables.

Mushroom consumption is probably also correlated in Western countries with higher social class, for example, but not in Eastern Europe. Or maybe it used to be but isn't anymore, the whole thing is ghastly to unpick.

Just a few months back there was a bunch of stuff linked here that was stating the possibility of certain cancers being fungal in origin.

Perhaps eating more fungus allows the body the protect itself from the cancer causing fungal infections?

I certainly am not a specialist...just spitballing

These kinds of associations can easily be, and frequently are, spurious. Unless someone can find a reason why mushrooms might prevent cancer, I don't think the result is helpful.

I wish we could know who funds these studies. Perhaps this one is from the mushroom marketing board..?

The Mario games knew all this time.

Reply on news.ycombinator.com