Colorectal Cancer News
Underweight Also at Increased CRC Risk
A new study funded by the United States National Cancer Institute has found that underweight people are at about an equal risk for colon cancer as those who are overweight. The study, which involved more than 50,000 people, found that those with a body-mass index (BMI) of 21.5 to 24.4 – largely to be considered the ideal weight - only 89 out of 100,000 had colon cancer. The number increased slightly for those with BMIs of 18.5 to 21.4 and 24.5 to 27.4, as the number of cases went up to 103.
By contrast, for those with BMIs of 18.5 or less – usually considered underweight - the incidence shot up to 119, 33% higher than those within the ideal BMI. Among those with a BMI of 27.5 or above, the incidence of colon cancer was 130, about 46% higher than the ideal group.
Researchers were quite surprised at the findings, and hypothesized that the higher risk for the underweight group could be caused by “oxidative DNA stress,” or mild inflammations common in the underweight. These inflammations damage the immune system and allow cancer cells to multiply. This is different than in the overweight. It is believed that those in the overweight group have more insulin in their system, which may decrease the body’s ability to prevent tumors.
While the group also looked at rectal cancer, there was not a noticeable difference between the groups.
Hui, Lu. Skinny people also face colon cancer risk: study. Xinhua News Agency. 2011 May 3.