Tag Archives: cancer

Meat, Processed Meat and Cancer Risk: Interview

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:

WHO tells us about red meat and processed meat cancer risk?

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’

IARC Groups

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 โ€œinadequateโ€ 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.

Does Cell Phone Use Cause Cancer? No.

Josh Harkinson at Mother Jones recently posted an item called “Scores of Scientists Raise Alarm About the Long-Term Health Effects of Cellphones.” I like Josh’s work, but there are some problems with this article I want to point out, some of which parallel problems in the more general discussion of cell phone safety.

Before looking at the Mother Jones piece, here’s the bottom line: There is no known mechanism by which cell phone use can lead to cancer (usually, brain cancer is of concern). There have been many studies on this and related issues. They vary in quality and in what they look at. The studies that seem to indicate an increase in some kind of cancer with cell phone use would indicate a shift from a very very very unlikely chance of cancer to a very very unlikely chance of cancer. So if there is an effect reflected in this research, it is very small. The studies that seem to show a link are generally done by a limited group of researchers, use methodology that is not reliable and can not be used to attribute cause, and are situated within a literature that includes many studies that show no link. Different studies that may show a link between cell phone use and cancer often indicate a link to a different cancer. And, tellingly, brain cancer rates over recent decades are basically flat, cell phone use explosive. If cell phones increase the risk of brain cancer, it is a phenomenon that a lot of research has failed to clearly demonstrate, and if the effect is there, it is very small and entirely unexplained by physics or physiology.

Josh Harkinson discusses an important topic but does so that in a way is uncomfortably click-baity. (I assume this is in part the effect of the editors who chose the title and possibly the accompanying graphic). The title implies that science raises a concern (an alarm) and the article is accompanied by a doctored photograph of a woman using a cell phone; She is wincing as though suffering a health effect and red cell phone cancer-kooties are seeping into her head right there in the picture. The subtitle invokes the children: “Children in particular may be vulnerable.” And, the article begins with an appeal to the latant distrust, “Are government officials doing enough to protect us.”

The article stems from a letter signed by “195 scientists from 39 countries” who “have collectively published more than 2,000 peer-reviewed papers on the subject.” How many scientist deal with the topic of non-ionizing radiation (the kind of kootie stuff that emanates from your cell phone) interacting with tissue (what your head is made out of)? I’m not sure, but a Google Scholar search on the term “biological health effects non-ionizing radiation” yields over 14,000 results. There are probably tens of thousands of scientists who work in the general area of radiation-cell interaction. This is a huge and important area of research. Various kinds of radiation have health consequences. Radiation interacting with tissues is a widespread form of therapy and imaging (everything from x-rays to MRI). The properties of various kinds of radiation and the activity of molecules in cells is part of a lot of basic research in a lot of fields. Here in Minnesota, there are probably way over 200 scientists who routinely engage in research either about or relying on the basic physics and physiology of radiation-cell interaction. It is a big area, only some of which directly addresses health effects of non-ionizing radiation, but even that small percentage involves a lot of work, many research labs, a large number of scientists, and a lot of publications.

The letter and information about it can be found here. Watch the video. Note that the “scientists” are actually “scientist and engineers,” an unintended dog-whistle indicating the padding of consensus claim. The letter is not about people holding cell phones to their heads. It is about EMF in general (with a focus on cell phones), and suggests that the ambient EMF including power lines are the problem. This borders on Chemtrail like ideation. I strongly recommend you watch the video. Critically.

A letter with under 200 signers (across 39 countries) who claim to have published a couple of thousand papers on a topic is numerically weak. The reality and importance of anthropogenic global warming is a scientific consensus. Even so, climate science denialists have come up with lists and letters like this with much more impressive numbers, but thay amount to nothing. There are a lot of scientists out there. There are about seven million scientists. It is not hard to find a couple hundred who strongly believe something that many many more don’t accept as likely. Josh’s article does not address this context, and probably should.

That cell phones may cause cancer has been officially designated by the World Health Organization as “possible.” That sounds bad. But people need to understand, and Josh did not point this out, that the “possible” category includes anything where there is virtually any research indicating a possible link, even crappy research, and even if the research exists among a huge body of research that fails to indicate a link. There are many different categorizations of cancer risk, and different organizations maintain these definitions and lists. The International Agency for Research on Cancer, part of WHO, has these categories:

Group 1: Carcinogenic to humans
Group 2A: Probably carcinogenic to humans
Group 2B: Possibly carcinogenic to humans
Group 3: Unclassifiable as to carcinogenicity in humans
Group 4: Probably not carcinogenic to humans

Items in group one are really problems. They cause cancer and include such things as silica dust, Radon, Soot, Tobacco, and Thorium. Group 2A (Probable) is pretty long and includes a lot of nasty stuff with multi-syllabic names, as well as ultraviolet radiation. Being a hairdresser is a probable cause of cancer because of exposure to chemicals, as is working in a petroleum refinery, or being a shift worker involving changing time of work on a regular basis. These are things that we may want to worry about, but that people still argue about, but, as they say, probably are linked to cancer.

Group 2B, “possible,” the list cell phones are in, is very long, over 900 items, of which about a third are specifically considered possibly linked to human cancers (the others not linked to humans). This list also includes a lot of scary looking stuff, but for which there is insufficient research to actually make the link. Vinyl acetate is an example. It is a liquid precursor for a polymer used to make a lot of stuff. Wikipedia tells us, “On January 31, 2009, the Government of Canada’s final assessment concluded that exposure to vinyl acetate is not considered to be harmful to human health. This decision under the Canadian Environmental Protection Act (CEPA) was based on new information received during the public comment period, as well as more recent information from the risk assessment conducted by the European Union.” So that is an example of a scary sounding thing for which some research may have shown a cancer link but that was ultimately determined by at least one major agency to not be cancer causing. Potassium bromate. Used for a lot of things, it is in some of your food (baked goods mainly). It is banned in many countries, not in the US. In theory, it is broken down during baking. Coffee. Coffee has been some research indicating a link between coffee consumption and bladder cancer, but other studies show a reduced risk of intestinal cancer. Overall, the evidence for any of this is weak.

Group 2B listing is used when there is limited evidence of a cancer link and usually insufficient evidence for a cancer link in lab animals. Let’s put a finer point on it by looking at what the UN says about the 2A and 2B categories (emphasis added):

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. In some cases, an agent may be classified in this category when there is inadequate evidence of carcinogenicity in humans and sufficient evidence of carcinogenicity in experimental animals and strong evidence that the carcinogenesis is mediated by a mechanism that also operates in humans. Exceptionally, an agent may be classified in this category solely on the basis of limited evidence of carcinogenicity in humans. An agent may be assigned to this category if it clearly belongs, based on mechanistic considerations, to a class of agents for which one or more members have been classified in Group 1 or Group 2A.

So, if you want to be careful, avoid Group 2A items. They may cause cancer, and you should worry about them.

Group 2B: The agent is possibly carcinogenic to humans.

This category is used for agents for which there is limited evidence of carcinogenicity in humans and less than sufficient evidence of carcinogenicity in experimental animals. It may also be used when there is inadequate evidence of carcinogenicity in humans but there is sufficient evidence of carcinogenicity in experimental animals. In some instances, an agent for which there is inadequate evidence of carcinogenicity in humans and less than sufficient evidence of carcinogenicity in experimental animals together with supporting evidence from mechanistic and other relevant data may be placed in this group. An agent may be classified in this category solely on the basis of strong evidence from mechanistic and other relevant data.

If you focus on the word “cancer” Group 2B may be scary to you, but many items on this long list are those for which we simply can not say there is no research project ever done that showed a possible link.

Josh notes that “For decades, some scientists have questioned the safety of EMF, but their concerns take on a heightened significance in the age of ubiquitous wifi routers, the Internet of Things, and the advent of wearable technologies like the Apple Watch and Fitbit devices, which remain in close contact with the body for extended periods.”

This points to a possibly unintended side effect of unnecessary concern over non-ionizing radiation. Non ionizing radiation is radiation that does not alter matter at the sub cellular level in a way that can lead to cancer or other negative effects. See this writeup for more detail on this important difference. All radiation reduces in its strength dramatically with distance. As your smart phone and your wi-fi router exchange information (when it is using that pathway to interact with the internet) the energy that comes out of the box across the room and the energy that comes out of the smart phone in your hand, at the point of, say, your nose (a proxy for your brain that allows us to discount the effects of your skin, skull, and dura matter reducing the signal) are many orders of magnitude different. Conflating concern over a cell phone pressed to your head with concern for wi-fi routers is like conflating concern over drowning in a pool with concern over drowning in the vapor that evaporated from the pool that give you that dank feeling as you sit nearby drinking your iced coffee drink form a polyvinyl acetate cup.

Except there really is a demonstrable risk of drowning in a pool.

This is a problem because there is a movement to remove wi-fi from all public spaces over health concerns. That is crazy talk. I wish Josh had noted that in his piece. The people who signed this letter are those same people … who want to remove wi-fi from your coffee shop.

A very very small number of researchers want to move cell phones from Group 2B to Group 2A, but even as they are asking for this, continued research on the cancer risk of cell phones a) fails to produce a mechanism by which this can happen despite a great deal of knowledge about radiation-tissue interaction and b) continues to show a possible link only in studies that are inherently flawed in their methodology. Such studies, mainly case-control studies, rely on people recalling their use of cell phones. People with brain cancer are asked to recall their cell phone use, and matched randomly chosen people without brain cancer are asked to do the same thing. (Not all studies are done just that way but key studies of relevance here were.) That is a great way to get a preliminary look at a possible health issue, but it is simply not how the actual connection between a substance, a technology or a behavior and a health effect is made.

We understand a lot about energy-tissue interaction. If non-ionizing radiation from cell phones caused cancer, we would have an inkling of the mechanism. We don’t. Cell phone use has exploded in recent decades, brain cancer has not. If cell phones caused brain cancer, it would be a visible epidemiological phenomenon. It is not.

I’ve been told (and some checking on the internet has indicated this is maybe important) that some of the material used to make cell phones comes naturally along with some radioactive isotopes. It is possible that these isotopes are not always removed properly. I do not know this is the case, but it is an interesting idea. A while back a shipment of cell phone cases that happened to be radioactive was located (and refused). Holding a radioactive cell phone case to your head several hours a day may be a health risk, though again, I don’t know this to be a fact, it probably depends on all sorts of things. The cell phone-cancer link is so weak that it may be a result of research bias, random effects, recall bias, or some effect related to the use of the cell phone but not to the non-ionizing radiation.

Smart phones are becoming so ubiquitous that they could almost be considered a key trait of our species. It is smart to be smart about smart phones. Worrying about the cancer link is probably not exactly stupid, but it isn’t particularly smart either.


This video addresses many of the topics I touch on here, and more:

American Cancer Society

You’ll recall that I wrote something about the American Cancer Society and fundraising a few weeks ago (here). That was a response to something Greta Christina wrote, and now, Greta has updated us on the situation and has this post that you must read: Has the American Cancer Society Been Caught Covering Up a Rejection of Atheist Money?

If it really is the case that the beliefs (or lack thereof) of donors for medical care and scientific research is affecting the flow of money, this is a concern. Please go have a look at Greta’s piece and the piece she links to and add your comments!