New News on The Red Meat/Processed Meat Cancer Risk

There is a well-established link between consumption of processed meat and cancer risk, particularly risk for colorectal cancer. Now, the link has been made more explicit, with the World Health Organization (WHO) stating that these foodstuffs can cause cancer, based on an evidence review by 22 scientists, the details of which were published in the journal, The Lancet. The link between consumption of red meat and cancer was less clear, but is considered probable.

This story has gotten a lot of press in the popular media. See here and also here and also here. A summary from these stories is:

The World Health Organization has deemed that processed meats — such as bacon, sausages and hot dogs — cause cancer.

In addition, the WHO says red meats including beef, pork, veal and lamb are "probably carcinogenic" to people.

A group of 22 scientists reviewed the evidence linking red meat and processed meat consumption to cancer, and concluded that eating processed meats regularly increases the risk of colorectal cancer. Their evidence review is explained in an article published in The Lancet.
 
The conclusion puts processed meats in the same category of cancer risk as tobacco smoking and asbestos. But this does not mean that they are equally dangerous, says the International Agency for Research on Cancer (IARC) — the agency within the WHO that sets the classifications. And it's important to note that even things such as aloe vera are on the list of possible carcinogens.

In a Q & A released by the IARC, the agency says that "eating meat has known health benefits," but also points out that the cancer risk increases with the amount of meat consumed. As we've reported, studies show that the heaviest meat eaters tend to have the highest risk.

The IARC says high-temperature cooking methods (such as cooking meat in direct contact with a flame) produce more carcinogenic compounds. However, the group says that therewere not enough data "to reach a conclusion about whether the way meat is cooked affects the risk of cancer."

Susan Gapstur of the American Cancer Society (ACS) says the society recommends "consuming a healthy diet with an emphasis on plant foods and limiting consumption of processed meat and red meat."

The recommendation, Gapstur tells The Salt, is based on research. For instance, a systematic literature review on colorectal cancer published in 2011 by the World Cancer Research Fund found a statistically significant, 16-percent increased risk of colorectal cancer associated with each 100 grams of red and processed meat consumed. As the ACS points out, this is an amount of meat roughly equivalent in size to a deck of cards.

There is of course controversy, some of which comes from groups labeled “a powerful lobbying industry.” Thus:

…the panel decision was not unanimous, and is expected to face criticism within the United States, where processed and red meat still forms the base of most meals, and is backed by a powerful lobbying industry.

The National Cattleman’s Beef Association, the national trade association that represents U.S. cattle producers, put out a press release soon after the WHO announcement that — not surprisingly — questions the findings. “Most scientists agree that it is unrealistic to isolate a single food as a cause of cancer from a complex dietary pattern further confounded by lifestyle and environmental factors,” the association says in the release.

“The available scientific evidence simply does not support a causal relationship between red or processed meat and any type of cancer,” Shalene McNeill, executive director of human nutrition at the National Cattlemen’s Beef Association said in the release.

In addition, more critical comments are:

"Scientific evidence shows cancer is a complex disease not caused by single foods and that a balanced diet and healthy lifestyle choices are essential to good health," writes Barry Carpenter, president of the North American Meat Institute, in a statement on the new WHO classification.

Carpenter says it's important to put this new classification in context. "IARC's panel was given the basic task of looking at hazards that meat could pose at some level, under circumstance, but was not asked to consider any off-setting benefits, like the nutrition that meat delivers or the implications of drastically reducing or removing meat from the diet altogether," the statement concludes.

I myself would trust more the scientists performing the evidence study, and the physician making the recommendations, than groups that have a vested economic interest in meat consumption, particularly consumption of red meat.

I myself eat red meat rarely, getting the vast bulk of my animal protein intake from chicken, turkey, fish, eggs, and dairy (all in moderation). As far as processed meat, I may have a breakfast sandwich a couple of times per month that has turkey sausage, but that’s it. My typical everyday diet does not include red or processed meat.

In my opinion, the wise choice is moderation. Eating red meat every day, or even multiple times per week, is in my opinion unwise given these data. Eating processed meat, such as bacon and lunch meats, more often than a few times per month is also unwise.

Note that cancer risk is directly related to the amount of these meats consumed. Keep in mind also that the definition of “processed meat” varies. Some would consider canned fish (tuna, salmon, etc.) to be “processed meat.” I eat those frequently; obviously I am not putting them in the same category as stereotypical processed meat like bacon or ham. Others specifically exclude canned tuna or salmon from the list, as I do, since the canning process, and addition of minimal amounts of salt, is not equivalent to the smoking, curing, or salting processes used for the foods typically considered “processed meats.” And of course, fish meat is not considered “meat” per se in the sense used by nutritionists, who focus on the flesh of land animals and birds.

Therefore, canned fish (in water, not oil!) should be considered different from eating a slab of bacon; eating such fish is considered healthy (but note certain types of tuna can have higher levels of mercury).

Update: list of red and processed meat.
Actionables: Eat less red meat and processed meat.