A few days ago the UN agency in charge of keeping track of cancer risks listed meat and processed meats as to some degree or another likely to cause an increase in cancer risks. I wrote about that here. More recently. I was interviewed by Joshua Holland on the Politics and Reality Radio show about that story. Here is the interview for your listening pleasure:
See what I did there?
As you know, the UN WHO International Agency for Research on Cancer has listed Red Meat as Group 2A (probably carcinogenic to humans) and processed meat at Group 1 (causes cancer).
And everyone is upset. The most common reaction to these listings is to criticize WHO. The least common reaction to these listings is to learn what the listings are, what they mean, what they mean to you, to the meat industry, to cancer research, and all that. Here, I will try to provide some perspective on some of this.
WHO is probably more likely to list something as cancer causing
It is probably true that the WHO IARC is somewhat biased, in that they are more likely to attribute possible carcinogenic effects to things than other similar groups. There are many substances and behaviors listed by WHO as possibly or probably cancer causing that are not similarly identified by, for example, the US EPA. This does not mean that WHO IARC is more likely to be wrong. It just means that your reaction to a possible agent being listed by WHO should be to understand this bias, but not to assume you know what the bias means. If every single cancer-watching agencies was biased in one direction, we’d have a problem. If all cancer-watching agencies always drew the same exact conclusions form the disparate research, we’d have a conspiracy. If the range of cancer-watching agencies produces a reasonable range of decisions, we’d have real life.
Here is something you should keep in mind when comparing across agencies. Many US federal agencies are led and staffed by industry experts. Where do you get industry experts? From the industries these agencies regulate. Where did the industries get them? They got them from PhD schools, where they quite possibly paid for their higher education with grants from the industry and worked in labs paid for in part by those industries, while working on grants from the industry. This is likely more a thing in the US than in other countries that contribute expertise and do research. It is also true that US regulatory agencies are notably biased in the opposite direction of WHO.
US regulatory agencies will be staffed by well meaning well trained people who know a lot about how the industry works. That is a good thing. US regulatory agencies will be staffed by people who owe their careers to the industry, and are likely to have warm fuzzy feelings about the industry. That is likely to lead to some bias.
On the other hand, in other parts of the world, wooish thinking seems to permeate science and governmental agencies more easily. If you look at the research and regulations, related to EMF risks (like power lines and cell phones and such) you’ll see a gradient where some areas of Europe have both evidence (from research) suggesting EMF-health risks and regulations related to this, and other areas of Europe where the evidence shows now risk, to the US where we by and large don’t regulate EMF using these risks as factors. A sensible view of the research tells us that EMF does not have the alleged health risks.
The reason this is important is that WHO is an international body, so we are going to see a range of industry-fuzzy vs. woo-fuzzy fringes surrounding a hopefully larger and sensible scientifically oriented core. This is also important because of this: if every regulatory or research agency or institution in the world really were funded by the industries they study, and no other research was done by anybody, problems will arise. So go ahead and be annoyed at WHO, but also appreciate this relationship.
It is not about how bad the cancer risk is
As a substance or behavior moves from Group 3, through Group 2B and 2A, to Group 1, this does not mean that it is thought to be increasingly cancer-causing. What it means is that the certainty that the substance or behavior cases cancer, no matter how small the effect, has increased. A given agent may increase the risk of a certain kind of cancer by 50%, which sounds bad, but the original probability of cancer being caused by that agent may be tiny. So, in effect, a tiny risk has been increased to a tiny risk. According to WHO, “The classifications reflect the strength of the scientific evidence as to whether an agent causes cancer in humans but do not reflect how strong the effect is on the risk of developing cancer.”
This is not about your bacon
I find it amusing that the Internet Reaction to these listings is so widespread and negative, even angry, and at the same time so poorly informed. This is amusing because we are just coming off a way over the top Bacon Worship phase.
I stopped eating bacon about four months ago. Do you want to know why? Because of all the pictures of bacon, excessive bacon, things made out of bacon, bacon being fetishized and revered like it was a god or something, on Facebook and elsewhere. I got tired of bacon. I was reminded of a friend’s comment. He was raised in a Kosher household. He told me, “I don’t have any food taboos, I don’t keep kosher. But if I walk into a house where someone is cooking ham, I want to throw up.”
(OK, I did have a BLT the other day. But it was hard.)
The point is, do think about the nature and cause of your reaction, if you are having a hissy fit about WHO and meats. Are you objecting to the WHO IARC criteria, which you’ve carefully studied and understand, or are you simply being sensitive about your stupid bacon fetish? Think about it.
Some food research is probably inherently wrong
I just want to throw this in. If you feed human food, especially cooked food, especially food not made of raw grains, to rats and mice, they might get sick, while a human being fed the same things won’t. Why? Because humans invented cooking possibly as long as two million years ago, and have adapted to cooked foods which seem to cause nasty problems for some lab animals. And humans and their ancestors have always eaten at least some meat. And we are not rodent granivores. So, I don’t know how much animal evidence is being used to change the groups for meat and processed meat, but I personally prefer to disregard rodent data on human diet. It seems to be almost always misleading. Just sayin’
Just so you know, here are the IARD Groups
Group 1: The agent is carcinogenic to humans. This category is used when there is sufficient evidence of carcinogenicity in humans. In other words, there is convincing evidence that the agent causes cancer. The evaluation is usually based on epidemiological studies showing development of cancer in exposed humans. Agents can also be classified in Group 1 based on sufficient evidence of carcinogenicity in experimental animals supported by strong evidence in exposed humans that the agent has effects that are important for cancer development.
Group 2 This category includes agents with a range of evidence of carcinogenicity in humans and in experimental animals. At one extreme are agents with positive but not conclusive evidence in humans. At the other extreme are agents for which evidence in humans is not available but for which there is sufficient evidence of carcinogenicity in experimental animals. There are two subcategories, indicating different levels of evidence.
Group 2A: The agent is probably carcinogenic to humans. This category is used when there is limited evidence of carcinogenicity in humans and sufficient evidence of carcinogenicity in experimental animals. Limited evidence means that a positive association has been observed between exposure to the agent and cancer but that other explanations for the observations (technically termed chance, bias, or confounding) could not be ruled out.
Group 2B: The agent is possibly carcinogenic to humans. This category is used when there is limited evidence of carcinogenicity in humans and less than sufficient evidence of carcinogenicity in experimental animals. It may also be used when the evidence of carcinogenicity in humans does not permit a conclusion to be drawn (referred to as “inadequate” evidence) but there is sufficient evidence of carcinogenicity in experimental animals.
Group 3: The agent is not classifiable as to its carcinogenicity to humans. This category is used most commonly when the evidence of carcinogenicity is inadequate in humans and inadequate or limited in experimental animals. Limited evidence in experimental animals means that the available information suggests a carcinogenic effect but is not conclusive.
Group 4: The agent is probably not carcinogenic to humans. This category is used when there is evidence suggesting lack of carcinogenicity in humans and in experimental animals.