Although study results vary, there is convincing evidence that regular intake of red meat (beef, pork, or lamb) and processed meat (ham, bacon, pastrami, salami, cold cuts, hot dogs, sausage, etc.) increase the risk of developing colorectal cancer. Chicken does not seem to have the same effect or risk.

Research from Europe on 478,000 men and women showed that those who ate the most red meat (around 5 ounces or more a day) were about 33% more likely to develop colon cancer than those who ate less than an ounce a day on average. The study also showed that eating chicken did not increase or decrease their risk. However, a high intake of fish seemed to reduce colon cancer risk by about 33%.

An American study (looking at 148,610 people between the ages of 50 and 74) showed the effects of long-term meat consumption. Like the UK research, eating a lot of red meat (as well as processed meats) was linked to a substantial increase in the risk of colorectal cancer. On the other hand, long-term intake of a high fish and poultry diet appeared to be protective and decrease risk of colorectal cancer.

Smoked and high-temperature cooked meats

Population-based studies have found that eating a lot of fried, well-done, or barbecued meats is associated with more colorectal, pancreatic, and prostate cancer.

Harmful chemicals are formed when meats, such as beef, pork, fish, or poultry are cooked using high-temperatures. This is generally done by pan frying, deep frying, or grilling directly over an open flame. Similar harmful chemicals are also formed during charring or smoking of meats, such as barbequing. These chemicals that are produced are believed to cause DNA (genetic) changes that could promote cancer.

Recommendations from experts

In 2007 the World Cancer Research Fund/American Institute for Cancer Research issued dietary guidelines recommending limiting red and processed meats, including smoked meats. Additionally, the World Cancer Research Fund/ American Institute for Cancer Research Continuous Update Project (WCRF/AICR CUP) recently released recommendations based on a review of 1,012 published studies. These new guidelines are unique in that they correlate the average amount of meat eaten daily with the risk of developing colorectal cancer.

Findings: Ounces of intake and the associated colorectal cancer risk:

  • 2.5 ounces of red meat per day (about 18 ounces/week) minimally increased risk
  • 3.5 ounces of red meat per day (24.5 ounces/week) increased risk by 17%
  • 7 ounces of red meat per day (49 ounces/week) increases by 34%

Processed meat carries an even higher risk:

  • 3.5 ounces per day increases risk by over 36%
  • 7 ounces per day increases risk by 72%

Try to limit processed meats, like hotdogs and cold cuts. And remember, while you want to limit high-temperature cooked meats, be sure that they are cooked to the proper temperature for food safety. And like with everything in the diet, remember, moderation is key.

Read more about colon cancer screening and prevention from David Carr-Locke, Chief of Digestive Diseases and Co-Director of the Center for Digestive Health at Beth Israel Medical Center.