Calgary, AB – The Canadian Cattlemen’s Association (CCA) has reviewed the monograph, Carcinogenicity of consumption of red and processed meat, as published today in The Lancet, which summarizes the International Agency for Research on Cancer (IARC) Review of Red Meat and Processed Meats. The Working Group charged with the review classified consumption of red meat in Group 2A, or “probably carcinogenic to humans,” which refers to a degree of certainty of causation. It is important to note that IARC conducts hazard assessments, not risk assessments. That means they consider whether meat at some level, under some circumstance could pose a risk. IARC has found hazards in about half of the agents it has reviewed.
In reaching the 2A classification, the Working Group’s review of 800 existing epidemiological studies from around the world “concluded that there is limited evidence in human beings for the carcinogenicity of the consumption of red meat,” and that “…no clear association was seen in several of the high quality studies and residual confounding from other diet and lifestyle risk is difficult to exclude.”
The IARC monograph reported that colorectal cancer was their principle focus relative to red meat and that “a meta-analysis of colorectal cancer in ten cohort studies reported a statistically significant dose–response relationship, with a 17% increased risk (95% CI 1·05–1·31) per 100 g per day of red meat.” The American Society of Clinical Oncology (ASCO) has estimated that “a person with an average risk of colorectal cancer has about a 5% chance of developing colorectal cancer overall.” By this estimate consuming 100 gram per day of red meat would increase the risk of colorectal cancer by just under 1% in absolute terms. The meat industry has previously estimated that on average Canadians consume approximately 50 grams of fresh red meat or half this amount. Accordingly, if there is an increase in the potential risk of colorectal cancer from red meat consumption, by these estimates it is small and must be considered relative to the very significant nutritional benefits that red meat provides.
While meat’s very significant nutritional benefits are not considered directly in the IARC evaluation, they did note that “Red meat contains high biological value proteins and important micronutrients such as B vitamins, iron (both free iron and haem iron), and zinc.” The World Health Organization has previously stated that 2 billion people – over 30% of the world’s population – have anemia, many due to iron deficiency. Beef is among the best food sources of well absorbed iron. Meat has long provided an important source of nutrients for Canadians and the industry takes pride in providing high quality beef products to consumers.
There are many theories why red and processed meat may be linked to cancer however it’s important to note that no scientific consensus has been reached.
Canadians hear a great deal about what foods we should eat and the perspective from the scientific community can change over time. Certainly cancer is a complex disease with many contributing factors including age, genetics, and lifestyle. As with so many aspects of daily life achieving the right balance for your individual circumstance is key and we continue to recommend to Canadian’s that they follow the Government of Canada’s Food Guide.
If consumers are concerned about the formation of compounds potentially associated with cancer risk while cooking beef there are a number of simple things that can be done to reduce potential risk while enhancing the eating experience. Approximately half of Canadians currently cook beef steaks to medium-well or well-done. It is known that cooking to lower levels of doneness can enhance tenderness and juiciness while also reducing the formation of substances which may increase cancer risk. When there is a need to cook beef to a spe¬cific recommended temperature, such as for burgers or mechanically tenderized beef, using a digital thermometer is helpful to ensuring that overcooking does not occur. Flipping burgers or steak more often can easily be accom¬plished and helps the meat to cook more evenly while avoiding overcooking at the meat surface. The use of mar¬inades can be effective, especially those that contain beer or wine, citrus juices like lemon or spices such as garlic or onion. These substances can prevent the formation of certain chemicals or counteract their presence.
The full IARC monograph, which details methodology, will be published at a later date in 2016. The CCA will review the monograph and methodology comprehensively at that time.