On Monday the World Health Organization’s International Agency for Research on Cancer (IARC) will release their evaluation of the cancer risk associated with red and processed meat. The findings, leaked to the press, will reportedly support AICR’s analysis of the research on this issue and our recommendation to limit red med meat and avoid processed meat.
updated statement: Diet–Cancer Experts Welcome WHO Report on Meat and Cancer
Here at AICR we haven’t had a chance to read the full IARC report yet. When we do, we’ll update this blog post with our reaction.
In the meantime, here is what we know for certain:
- Research shows a clear and convincing link between diets high in red meat and risk for colorectal cancer.
- Research shows a clear and convincing link between even small amounts of hot dogs, bacon and other processed meats to colorectal cancer.
The IARC report may be new, but the evidence showing a link between red meats and colorectal cancer is not news. For years we have been recommending that Americans reduce the amount of red meat (beef, pork, lamb) in their diets and avoid processed meats like bacon, sausage, hot dogs and cold cuts. This advice grows out of our report, Food, Nutrition, Physical Activity and the Prevention of Cancer: a Global Perspective and our recent report on colorectal cancer, This report, part of the Continuous Update Project, analyzed the global scientific research into the link between diet, physical activity, weight and cancer.
What you eat can play a big role in preventing colorectal cancer, with research showing that fiber-filled foods lower risk; red and processed meats increase it. Now a study hones in on how diet can affect risk, showing that swapping a high-fiber healthy diet for a low-fiber western-style diet alters gut bacteria and signs of inflammation that may play a role in colon cancer.
The study is published in Nature Communications and it adds to a growing body of research on how our bacteria – our microbiota – play a role in cancer risk.
For the study, researchers flipped the diets of 20 African Americans and 20 South Africans for two weeks. All the participants had colonoscopy exams before and after the diet swap.
The Americans were served African-style foods, almost quadrupling their fiber intake to an amount equal to over 3.5 cups of beans. At the same time, they cut their calories from fat in half. Africans went the opposite direction, dramatically cutting their fiber and upping their fat intake.
After two weeks on the African diet, the Americans had less markers of inflammation in the colon while those same markers increased among the Africans eating the less healthy diet. There were also opposing increases and decreases of the compound butyrate, which forms from digesting fiber and is linked to lowering colon cancer risk. The American group was producing more butyrate; the Africans on the American diet less. Continue reading
Following at least two healthy behaviors that are key AICR Recommendations, such as eating a healthy diet and being active, lowers the risk of colorectal cancer to some degree, with the more you follow the lower the risk, suggests a new study that highlights the importance of practicing multiple healthy behaviors.
Published in BMC Medicine, the study joins a growing body of independent research that investigates how AICR Recommendations for Cancer Prevention link to reduced risk of specific cancers, survivors, and mortality. Here are some of those other studies.
This latest study was conducted among 350,000 Europeans ages 25 to 70. They are part of the large European Prospective Investigation into Cancer and Nutrition (EPIC), which spans 10 countries. When people joined EPIC they gave information about their diet, smoking, activity and other lifestyle habits. Continue reading