Colorectal cancer is the second-leading cause of cancer-related deaths in the United States. Because of the prevalence of colorectal cancer, research efforts have focused on controlling its development by identifying environmental factors that may be associated with its development. Once such risk factors are identified and large studies confirm these findings, individuals will be able to make certain changes in their lifestyle, such dietary choices, in the hopes of personally controlling their risk for developing colorectal cancer.

Researchers from England recently reviewed data from previous studies in an attempt to identify an association between body mass index (BMI), which measures whether a person is overweight, and the risk of developing different types of cancer.1 This data was obtained from Medline and Embase and included studies conducted between 1996 and 2007. Among these patients, both men and women who had a higher BMI (more overweight) had significantly increased rates of colorectal cancer compared with those with a lower BMI.

Because higher BMI has been linked with increased rates of several different cancers, more questions about diet have been raised. These include interest in foods that may have a protective effect against certain cancers. Research has indicated that diets high in fruits and vegetables appear to significantly reduce the rates of some cancers. On the other hand, high consumption of certain meats, namely those that are highly processed, fatty, or grilled, is linked to an increased risk of some cancers. Additional confirmation of these findings is warranted.

Further evaluation of the potential association between meat consumption and cancer risk was conducted by researchers affiliated with the National Institutes of Health. This study included approximately half a million people. When the study began, between 1995 and 1996, participants were aged 50–71 years. Food questionnaires concerning meat consumption were administered at the beginning of the study. Individuals were followed for more than eight years. Red meat included beef, lamb, or pork, while processed meats included bacon, sausage, and ham.

  • Risk of developing any type of cancer with highest red meat consumption was increased from 20–60% compared with lowest red meat consumption.
  • Colorectal cancer rates were increased by 20% among those who ate large amounts of processed meats compared with those who ate lesser amounts.

The researchers concluded that “…decreased consumption of red and processed meats could reduce the incidence of several types of cancer.”

Together these two studies provide further evidence that both weight and diet can significantly affect the risk of developing colorectal cancer.  Specifically, being overweight and eating large amounts of red and processed meats significantly increases an individual’s risk of developing colorectal cancer.  The good news is that diet and body weight can be controlled on a personal level. These findings give individuals even more reason to take control of factors in their life that impact their health.


1 Renehan A, Tyson M, Egger M, et al. Body-mass index and incidence of cancer: a systematic review and meta-analysis of prospective observational studies. The Lancet. 2008;371:569-578.