According to the National Cancer Institute, colon cancer occurs in approximately 2 percent of Americans, and your risk of colon cancer increases with age. Many medical, genetic and lifestyle factors, such as diet, can increase your risk of developing colon cancer. While red meat does not directly cause colon cancer, a diet high in fat, and particularly high in red and processed meats, might increase your risk of colon cancer.
Background
Colon cancer occurs in the lower part of your digestive system and usually begins as small collections of cells known as polyps, which are initially very small and do not cause symptoms. Over time, polyps can develop into cancer. Symptoms of colon cancer can include diarrhea or constipation, rectal bleeding, abdominal cramping or gas, weakness, fatigue and weight loss. Screening for colon cancer by colonoscopy, a test that allows a gastrointestinal specialist to directly view your intestinal tract, can allow for the early detection of polyps or cancer. This screening is recommended every 10 years beginning at age 50 for most people.
Possible Association
According to Harvard Medical School, a meta-analysis of multiple studies of meat consumption demonstrated a 28 percent increased risk of colon cancer with high consumption of red meat, and an increased risk of 20 percent with high consumption of processed meat. Two 4 oz. portions of red meat per week should be safe, but limiting red meat -- as well as processed, cured and salted meats -- will help you avoid an increased risk of cancer. Foods that might lower your risk of colon cancer include fruits, vegetables, whole grains and fish.
Possible Mechanisms
Chemicals known as heterocyclic amines are produced when meat is cooked at high temperatures and might play a role in cancer. Additionally, a high-meat diet results in high levels of N-nitroso compounds, chemicals that might cause cancer, in the stool. N-nitroso compounds cause DNA changes in the cells lining the colon of people consuming this high-meat diet. Consuming a high fiber diet while eating a lot of red meat results in the production of an intermediate number of these compounds.
Considerations
Your personal risk of colon cancer depends on many factors other than red meat consumption. If you are over age 50, are African-American or have had colon cancer in the past, your risk of colon cancer is higher than the average person's. Other medical conditions, such as inflammatory intestinal conditions, diabetes and obesity, also increase your risk of colon cancer. In addition to red meat consumption, alcohol use and a low-fiber diet are other dietary risk factors. Discussing your individual risk of colon cancer with your physician will enable you to make an appropriate plan for screening and prevention.
