This is a bit shocking and I'll get downvoted for it but:
Not to mention that red meat is a class 2 carcinogen (Source: WHO). And processed meat, is a class 1 carcinogen, right up there with Plutonium, according to the World health organization.
That statement is factually correct but worded in a way that suggests a misunderstanding of the WHO classification system. "The lists describe the level of evidence that something can cause cancer, not how likely it is that something will cause cancer in any person (or how much it might raise your risk)."
> This is a bit shocking and I'll get downvoted for it but:
Not to mention that red meat is a class 2 carcinogen (Source: WHO). And processed meat, is a class 1 carcinogen, right up there with Plutonium, according to the World health organization.
I downvoted you not because of what you wrote, but because what you wrote is directly refuted by your (unlisted no less which I find intellectually lazy) source.
Processed meat being a class 1 carcinogen doesn't mean that plutonium = read meat! It simply means there is a likely link between it and cancer. Not that they are equivalent. This statement is scaremongering at best, unsupported by the classification. Also "cancer" is vague, the WHO organization, IARC, listed colorectal cancer as the specific cancer.
And for red meat being a class 2 carcinogen, they listed as probably not that its known.
From their FAQ:
This recommendation was based on epidemiological studies suggesting that small increases in the risk of several cancers may be associated with high consumption of red meat or processed meat. Although these risks are small, they could be important for public health because many people worldwide eat meat and meat consumption is increasing in low- and middle-income countries. Although some health agencies already recommend limiting intake of meat, these recommendations are aimed mostly at reducing the risk of other diseases. With this in mind, it was important for IARC to provide authoritative scientific evidence on the cancer risks associated with eating red meat and processed meat.
Note that phrase: "Although these risks are small"
If you want to paint red meat with a broad "bad for humans and whatnot" brush. At least get your facts straight. I can't look at the paper cause its behind the elsevier paywall but it should be here for anyone that can get it.
I bet the 18% more chance of colorectal cancer listed in the study amounts to for 500 people instead of 4 getting cancer, maybe 5 do now. One of my biggest pet peeves with all of this is the focus on whatever number is higher without contextualizing it.
My back-of-the-envelope numbers are close to yours, but I think a very big caveat is the confidence of these associations from epidemiological studies. 18% percent is quite low by most standards. Most epidemiological studies expect 100%-400% to draw strong correlations. Smoking, by example, is in the thousands of percent increase risk.
"In adequately designed studies we can be reasonably confident about BIG relative risks, sometimes; we can be only guardedly confident about relative risk estimates of the order of 2.0, occasionally; we can hardly ever be confident about estimates of less than 2.0, and when estimates are much below 2.0, we
are quite simply out of business." [1]
The estimate of 1.18 would probably be regarded as low. While the numbers we calculated may be nothing to sneeze at, I think we should be extremely cautious about our confidence in interpreting those values to real-world conclusions.
The 18% and 4/5 in 500 is just an example I pulled out of my butt. I didn’t do a scihub search to find the study but 18% is pretty weak. It’s also more for an assessment at a personal level how much risk you could expect as an individual, which most people care about. Even if that means 600k more cancer patients than before, you’d have to compare that against the null hypothesis to even see if you’re still in the territory of what random chance could arrive at.
An example I can off the top of my head remember is related to how much risk there is for women to have children post 40. It is a 100% increase in birth defects. From 0.5% to 1.0%, sounds bad right? Well its out of like 100 000 people and was based off of 1600’s era French women. Always take studies like this with a grain of salt and look at the numbers to assess personal risk.
Making lifestyle changes purely off of these studies is premature in my opinion. But you do you.
Not to mention that red meat is a class 2 carcinogen (Source: WHO). And processed meat, is a class 1 carcinogen, right up there with Plutonium, according to the World health organization.