The media has been buzzing with news that the World Health Organization just classified red meat, especially the processed kind, as a carcinogen.
One theory as to why this is the case points to the iron in meat, which interacts with nitrites (added as preservatives) in a way that creates carcinogens in your body during digestion. This explains why processed meat is carcinogenic but still does not explain why unprocessed meat, with no added nitrates, can increase risk for cancer and other diseases.
However, the study was comprehensive enough that consumers should be taking inventory on the amount of meat they are eating on a weekly basis. The 22 scientists who came up with these concerning results about the correlation between meat consumption and cancer drew evidence from two major studies: the Health Professionals Follow-up Study and the Nurses’ Health Study.
These studies observed more than 100,000 subjects who voluntarily completed questionnaires about the frequency and quantity of their meat consumption compared to other food groups. These volunteers were surveyed for decades to follow their health trajectories throughout their lifetimes, and found that the more meat a subject ate, the more likely they were to contract cancer or another disease that might lead to premature death.
Michael Pollen discusses both of these studies in his bestselling book, “In Defense of Food,” where he famously wrote, “Eat food. Not Too Much. Mostly Plants.” This is a sentiment that many, if not all of the scientists involved in this new carcinogen classification have expressed.
“Limiting [red meat] consumption to two to three times per week would be wise,” said Marji McCullough, Strategic Director for Nutritional Epidemiology at the American Cancer Society.
Completely eliminating meat from your diet is not recommended by the study in any way. In fact, The Lancet, where the official paper was published, states that red meat contains “high biological-value proteins and important micronutrients such as B vitamins, iron, and zinc… ARC’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.”
There is much critique of this study because the World Health Organization included so many potentially carcinogenic foods in its risk assessment list, including aloe vera and coffee. This made the risk of meat consumption seems almost inconsequential.
However, the risk that meat poses is significant in these studies and should be considered by the public at large despite the fact that popular media may have created unheeded hype about this new classification.
The W.H.O has found 800 peer-reviewed studies that show associations between meat consumption and cancer risk. A report published in 2011 by the World Cancer Research Fund found a 16 percent increased risk of colorectal cancer with each daily dose of 3.5 ounces of red or processed meat. 3.5 ounces is about the size of a deck of cards, a fraction of the realistic serving on most American plates.
This year, the IARC (International Agency for Research on Cancer) says that approximately 1.8 ounces of processed meat eaten on a daily basis increases the risk of colon cancer by nearly 18 percent.
Anahad O’Connor, a writer for the New York Times, shares some doubt about the validity of a correlation between meat consumption and cancer. He writes, “Of the more than 900 potential carcinogens the W.H.O. has evaluated since 1971, it has determined that only one—a nylon-manufacturing chemical found in drinking-water supplies—is ‘probably not’ carcinogenic.”
However, O’Connor also notes that even if a moderate amount of meat does not cause cancer, it is harmful to environment and should be a controlled substance for that reason alone. “By no means am I a staunch defender of red meat,” said O’Connor. “It has a greater impact on the environment than any other food in our diet: an estimated 20 percent of all greenhouse gases are attributable to raising animals for food.”
If you choose to uphold the absolutist values of compassion and sustainability that vegan or vegetarianism encompass, you will do the environment and farm animals a favor by compensating for the dramatic overconsumption of the average American meat-eater. However, according to the scientists behind these studies, no one has to completely cut meat out of their diet to achieve optimal health.