It would seem that by now the force of the evidence behind the link between meat consumption and increased risks of colon cancer and early death is great enough to make a vegetarian out of us all.
The research goes back decades and decades, and by now involves vastly different populations in huge numbers, including women, men, and people of various ethnic backgrounds in Europe and America. The research tends to involve massive “cohort” studies, which track the eating routines of basically healthy populations of tens or even hundreds of thousands over many years.
In the 1980s, for instance, Harvard Medical School, with funding from the National Institutes of Health, did a study of 88,751 women all over the age of 34, concluding by 1990 that those women who consumed more meat and animal fat were positively associated with an increased risk of colon cancer. About 150 of them were diagnosed with cancer after six years. Meat consumption was also associated with breast cancer. Fish, skinless chicken, fiber, and fruits and vegetables were, as can be expected, associated with a decreased risk of cancer and better general health.
But recently the biggest study of all, from the European Prospective Investigation into Cancer and Nutrition (EPIC), released results from its own cohort study of over half a million Europeans. The massive research project followed people in ten different Eurozone countries for 13 years.
Though the results were similar, the standards were different. There was no discussion of vegetable consumption, but rather just a focus on red meat, processed meat, and their relation to what is known as ‘all-cause mortality.’
The study found that after 26,344 deaths (due to any cause) in 13 years, over 3% of them (about 790 people) could have been prevented if their processed meat consumption had been around 20g a day or less.
The studies do have some limitations.
Namely, time. Although these major studies involve enormous populations, it’s not feasible that they involve enormous periods of time. The studies were only able to keep tabs on the participants for a certain number of years, in this case 6 and 13. It may be that far more deaths could be associated with meat consumption given another ten or twenty years of study. In addition, other kinds of fat, vegetable fat for instance, may be seen after enough time to have a positive association with cancer and all-cause mortality as well.
In addition, the mechanism whereby fat, meat, or processed foods cause cancer is not known. The most recent study from EPIC, in fact, with its predetermined focus on processed meat (sausage, bacon, hamburger) of a generally low quality, should be understood to be as damning for the specific food processing methods (the salts and preservatives) as it may be for the meat itself.
Indeed, a piece from the BBC published about the study (which was originally published in the journal BMC Medicine) quoted Roger Leicester, consultant surgeon for the Meat Advisory Panel who said: “We need to know what the preservatives are, what the salt content is, what the meat content is…meat is actually an essential part of our diet.”
Not only that, but given the size and scope of the study it would not be possible to give a comprehensive analysis of the participants’ overall lifestyles, including other foods eaten, exercise, drug use, and other factors, and what affect that would have on cancer and mortality rates. Professor of medicine from the University of Zurich, Dr. Sabine Rohrmann, was also quoted by the BBC, saying: “Stopping smoking is more important than cutting meat, but I would recommend people reduce their meat intake.”
Rohrmann, among others in the medical and scientific community, have reservations about putting too much emphasis on meat-as-carcinogen for very good reasons. Lean meat happens to be a critical source of iron and protein, nutrients in the human diet which are hard to get elsewhere. So hard, in fact, that doctors perfunctorily prescribe iron supplements to newly pregnant women or women who are planning on getting pregnant, knowing from experience that the average woman won’t get enough meat in her normal diet.
What it Really Means
Despite the strong evidence, and the huge studies, it is actually not a fact that meat causes cancer. Even those responsible for undertaking the research would say so. What the majority of doctors recommend is less meat—not no meat—and absolutely no processed meat. Eating moderate portions of lean and unprocessed meats, along with healthy portions of fresh vegetables and grains, is balanced and nutritious, and puts the human body at no increased risk for cancer of any kind.
Even with the positive association of meat and cancer, the rates can’t be said to be incredibly high. Some meat-eating readers, and presumably many more people besides, would prefer a 3% chance of a colon cancer diagnosis to a life bereft of one of their favorite foods. Given the studies done on happiness, depression, and life expectancy, there could even be a positive association between the happiness that meat may inspire and an increased life expectancy.
But who knows how many years we’ll be waiting for the results of that cohort study.