Dietary patterns and lifestyle are important considerations in this discussion.
This week's news of the link between colorectal cancer and processed meats from the International Agency for Research on Cancer (IARC), the cancer research agency of the World Health Organization, has certainly caught the attention of the media, and likely most people who enjoy bacon, sausage, ham, deli meats, jerky (all processed meats), or red meats. I can't say it is news to anyone in nutrition science, however. Several years ago published research demonstrated that high temperature cooking of red meats, as in barbequing and frying; increased the risk of producing carcinogenic compounds, especially when consuming blackened meats. Additionally, nitrates and nitrates used in preserving processed meats may form carcinogenic compounds.
Processed Meats and Cancer Risk
What is new is the IARC has published a review of research showing the amount of cancers per year they calculate will be caused by consumption of processed meats. They state 34,000 deaths per year are caused by processed meat consumption, which equates to eating 50 grams (roughly 2 oz., the size of 2/3 of a deck of playing cards) per day. Eating this amount daily raises an individual's risk of contracting colorectal cancer by 18%. They cite the increasing consumption of processed meat worldwide as a cause for concern, since traditionally plant and seafood proteins have been the main source of dietary protein.
Red Meat and Cancer Risk
As for red meat, the IARC did not find consumption causes cancer, but a positive association, so more research is needed. Certainly red meats provide complete protein, iron, B vitamins and zinc, all essential nutrients. The U.S. Dietary Guidelines from 2010 and the new Scientific Report of the 2015 Dietary Guidelines Advisory Committee (we are still waiting on USDA and the Department of Health and Human Services to finalize the research into the 2015 U.S. Dietary Guidelines) focus on unhealthy and recommended healthy dietary patterns. A registered dietitian/nutritionists (RDN) can then use this updated summary of nutrition research as a basis for nutrition education and population diet recommendations. Individualized nutrition recommendations are made on a person's diet and medical history, family health history, and lifestyle habits (i.e. exercise, stress levels) along with current nutrition research-based recommendations.
What is a Healthy Dietary Pattern?
To put this study into perspective, if a person consistently or frequently eats 2 ounces of processed meats daily, has a family history of colon cancer, does not exercise regularly, is overweight or obese, and eats little fruits, vegetables, or whole grains, it would be advisable to make some changes to reduce their risk of colon cancer (as well as type 2 diabetes, heart disease, high blood pressure and stroke). The healthy dietary patterns promoted by the Dietary Guidelines continue to include meat, but most Americans consume much more than the recommended amounts (such as 6 oz. per day of protein for a 2000 calorie eating plan). Also to improve health, the Dietary Guidelines recommend we increase our consumption of seafood, beans, nuts, seeds as protein sources, and low fat dairy. Increasing fruits, vegetables, and whole grains, with their high sources of fiber, have also been positively associated with decreasing colorectal cancer risk, as have a healthy weight, daily moderate exercise, and calcium. For more information, contact the American Institute for Cancer Research. See also our Penn State Extension Nutrition, Diet and Health programs to find more ways to make you and your family's dietary pattern and lifestyle healthier.