Higher intakes of dietary fiber are associated with a reduced risk of colorectal cancer,[1][2][3] but it is unclear whether RS has a similar effect.
Some in vitro study and animal studies have suggested that RS could have a beneficial effect on colorectal cancer prevention (particularly related to butyrate production),[4] but clinical trials to date have not found any beneficial effect.[5][6] Interestingly, preliminary research suggests that RS supplementation might offset some of the potentially negative effects of red meat consumption on colorectal health. One study found that RS (40 g/day) supplemented alongside a high-red-meat diet (300 g/day) increased fecal levels of SCFAs and reduced the formation of DNA adducts in rectal tissue cells, compared to the high red meat diet alone. DNA adducts occur when a potentially cancer-causing compound (as can be found in some red meats or produced through their bacterial fermentation) binds to cellular DNA, which could induce cell mutations leading to cancer.[7]
Ultimately, clinical trials with larger sample sizes and longer durations will be required to better understand the relationship between RS and colorectal cancer prevention.