Nutrition Notes: Cut colon cancer risk

A new blood test for colon cancer risk may be on the horizon that measures levels of C-reactive protein (CRP), which is produced by the liver during periods of acute inflammation. High levels of CRP in the blood are regarded as an inflammatory marker. They are also associated with a greater risk of heart disease. A new study now links this inflammatory marker with the risk of developing colon cancer.

The study, recently published in the Journal of the American Medical Association, found that levels of CRP were significantly higher in people who developed colon cancer up to 11 years later compared to people of similar age, sex and race who remained cancer-free. Laboratory studies already show that inflammation can promote the conversion of noncancerous colon cells to cancerous forms.

If increased CRP levels correlate with greater colon cancer risk, then weight control becomes much more important. Even being overweight (not necessarily severely obese) raises CRP levels. Excess body fat releases substances that promote inflammation. In addition, when fat accumulates in the liver, that organ produces inflammatory substances as well. Inflammation, however, is not the only reason to avoid excess weight. Scientists already consider overweight a risk factor for colon cancer because of the elevated levels of the hormone insulin that often come with excess body fat.

A healthy diet appears to be an effective way to reduce inflammation throughout the body, thus lowering colon cancer risk. A balance of different types of fat seems to be an especially useful prevention strategy. Consuming enough omega-3 fats — abundant in fish and fish oils, flax oil and certain nuts and seeds — reduces production of enzymes that stimulate inflammation. Some scientists believe that antioxidants and other substances in fruits and vegetables might help control inflammation, too.

A healthy diet that fights inflammation is the same as one that helps prevent cancer. An excellent choice is a mostly plant-based diet. High in fibre, this diet has healthy kinds and amounts of fat, when eaten in portions suitable for your calorie needs. Such a diet provides cancer-fighting nutrients, while it helps control weight, along with inflammation and hormones like insulin. Physical activity is another important way to fight off chronic inflammation, as well as reduce cancer risk.

“Nutrition Notes” is provided as a public service by the American Institute for Cancer Research, 1759 R Street, NW, Washington, DC 20009