The study, published recently in the journal PLoS One found that obesity seems to increase the likelihood for developing precancerous growths called colorectal polyps, according to new research that offers fresh insight into colon cancer risk.
In this study all the men underwent colonoscopies. In addition, the team noted BMI scores, waist measurements and leptin levels for all participants.
Roughly four in 10 of the men were found to be obese (with a BMI of 30 and up), with 78 percent falling into the category of either obese or overweight. Also, when focusing on the overweight/obese group, the team found that 30 percent had more than one polyp.
After cross-referencing overall results, the investigators determined that men who were obese faced a 6.5 times greater risk for having three or more colorectal polyps than those who were lean (with a BMI under 25).
Obese men were also found to face an almost eight times greater risk than lean men for having at least one polyp as opposed to none.
What’s more, polyp risk seemed to rise incrementally with body fat status. Specifically, polyp risk was seen to rise by a factor of nearly three when lean men were compared to overweight men. And risk went up again by the same amount when comparing overweight men to obese men.
Importantly, the team also found that having higher levels of the fat hormone leptin was similarly associated with having a higher risk for developing polyps.
Precancer cells, like you find in a polyp, are very sensitive to leptin. Leptin increases with fat cell size and number. So in a laboratory setting and with animals we’ve seen that leptin makes these early cancer cells grow.
Obesity has been associated with several types of cancer, colon cancer just being one of them. So whatever the exact mechanism is behind why excess body fat seems to promote colon cancer risk, this work continues to demonstrate the importance of maintaining a healthy body weight and, therefore, eating a healthy diet.