Recent results from a study titled “A Prospective Study of the Effect of Bowel Movement Frequency, Constipation, and Laxative Use on Colorectal Cancer Risk”, published in the American Journal of Gastroenterology, suggest that the type of laxative a person takes could be a factor associated with the risk of developing colorectal cancer (CRC).
Previous data have hinted on the link between laxative use and increased risk in CRC development, however, the existing epidemiologic studies have proven inconclusive.
With this clinical gap in mind, the research team, led by Jessica Citronberg, a predoctoral fellow at Fred Hutchinson Cancer Research Center in Seattle, analyzed the association between CRC incidence and constipation, 10-year non-fiber laxative use, and fiber laxative use by means of questionnaire among 75,214 participants of the VITamins And Lifestyle study.
Patients were followed from the time of questionnaire (2000–2002) until 2008 for CRC incidence, with a total of 558 cases of CRC reported.
The results demonstrated that individuals who used fiber-based laxatives at least four days a week for four years were 56% less likely to develop colorectal cancer than those who didn’t.
On the contrary, people who used non-fiber laxatives five or more times a year had a 49% increased risk for colorectal cancer. However, nosignificant associations between bowel movement frequency or constipation and CRC risk were observed.
“I was just surprised to see such a strong association between laxative use and colorectal cancer risk. I didn’t expect the results to be as strong as they were,” Dr. Citronberg said in a Hutchinson Center news release.
This is the first study to specifically examine the association between fiber or bulk laxatives and colorectal cancer risk.
In the authors’ opinion, soluble-fiber laxatives may confer some of the protective effects thought to exist in dietary fiber. The consumption of dietary fiber can then help reduce colorectal cancer risk by diluting carcinogens in the stool, boosting the growth of healthy bacteria in the colon, and increasing stool transit time, this way reducing the amount of time carcinogens are in direct contact with the colon.
Nonetheless, the study has some limitations, and as such, more research will be necessary before clinical conclusions can be taken regarding laxative use.
“I wouldn’t necessarily jump the gun and say because of this study people should stop taking stimulant laxatives. I think the better route to go would just be to have a healthy diet. I guess the takeaway is there’s no association between bowel-movement frequency, constipation and colorectal cancer risk, but we did see an association with laxative use. While the study results suggest that non-fiber laxatives increase your risk and fiber laxatives decrease your risk of colorectal cancer, more research is needed”, Dr. Citronberg concluded in the press release.