I’m sure you’ve all heard by now about the latest press release from the WHO (World Health Organization) evaluating the carcinogenicity of the consumption of red and processed meat. Now that the dust has settled and everyone has developed their own opinion on the matter, let’s look at it from a Sports Dietitian’s point-of-view.
To summarize, on October 26th WHO released a statement based on a meta-analysis completed by Chan, Lau, Aune, et al (2011) claiming the following:
“Processed meat was classified as carcinogenic to humans (group 1), based on sufficient evidence in humans that the consumption of processed meat causes colorectal cancer…” and “The consumption of red meat as probably carcinogenic to humans.”
Although the pathology of why red and processed meat causes cancerous cells is not clear, they believe that it has something to do with the nitrogenous compounds that are broken down from both red and processed meat in the gut. This can cause damage to cells in the bowel and increase the risk of cancer cells to develop (Chan et al, 2011). Processed meats are rich in nitrate preservatives while red meat has an abundance of heme that can become nitrosylated, and essentially cause harm similar to that of meats rich in nitrate preservatives.
Although it is a bold statement to claim that processed meat causes cancer, I don’t know what the big uproar is all about because this isn’t exactly new information. It’s been well established in the literature that processed meats have been linked with increased incidences of colorectal cancer. In 2007, an international panel of experts reported that high intakes of red and processed meat convincingly increases the risk of colorectal cancer (Chan et al, 2011). Recommendations for reducing red and processed meat have been around even since the 50s. In fact, dietary recommendations through organizations such as the Canadian Cancer Society and Dietitians of Canada have supported this for years. A quote from a handout created in 2008 from The Global Resource for Nutrition Practice:
Limit red meat (beef, pork, lamb and goat) to no more than 500 g (16 ½ oz) cooked weight per week…. eat very little, if any, cured or smoked meat. If you choose to eat processed meat at all, save it for special occasions like ham at Christmas or the occasional hot dog at a hockey game.
Oh and if you’re shocked, yes red meat isn’t just from beef! And processed meat includes things like ham, bacon, sausages, and basically any deli meat you can dream of.
Although this information may cause bacon lovers to shed a tear and pigs around the world to snort with joy, take this information with a grain of salt. Risk is relative. The experts established that a 50 gram portion of processed meat eaten daily increases the risk of colorectal cancer by 18% (Chan et al, 2011). The risk is still quite low. The chances of developing cancer from chronic cigarette use is still much greater, even though they are placed in the same carcinogen risk group.
Through all this negativity however, I think there are some positive aspects about the statements made by WHO. This might be an eye opener to individuals who are on a low carb kick for weight loss or for those trying to “eat clean”. There has been this big push in the health and fitness industry to consume more protein, often animal-based. Individuals might think twice before chowing down on 300g of deli meat for a snack and maybe opt for making a fresh salad with lean baked meats or choose vegetarian sources of protein. Nitrates aside, processed meats are excessively high in sodium and saturated fat. And reducing animal meat consumption is not only beneficial for your health, but also a more environmentally friendly way of eating.
Although there is an association with red meat and colorectal cancer, red meat still has some valuable qualities. It is a great source of iron, zinc and B12 for instance. And don’t forget that in sports nutrition, it’s a beautiful pairing of complex carbs with lean protein that leads to the gains in athletics, not simply protein alone.
At the end of the day, the general rule of thumb still remains the same. I don’t see the dietary guidelines changing drastically, because they have already been promoting this very thing; choose fish, seafood, poultry, and vegetarian sources of protein such as tofu and beans more often, limit your red meat to a couple times a week, and save yourself that thick cut of bacon for next time.
Emilie Trottier, Registered Dietitian, Sports Dietitian
Chan, D. S. M., Lau, R., Aune, D., Vieira, R., Greenwood, D. C., Kampman, E., & Norat, T. (2011). Red and Processed Meat and Colorectal Cancer Incidence: Meta-Analysis of Prospective Studies. PLoS ONE, 6(6), e20456. http://doi.org/10.1371/journal.pone.0020456
2008. Eating guidelines for cancer prevention; meat, nitrates and barbequing. Canada: The Global Resource for Nutrition Practice.