Colorectal cancers, which encompass cancers of the colon or rectum, have been on the rise among young individuals globally since the 1990s. While the exact reasons for this increase remain elusive, potential risk factors identified by the Center for Disease Control include inactivity, obesity, low dietary fiber intake, alcohol consumption, tobacco use, and “Western dietary patterns” characterized by high amounts of red and processed meats, added sugars, and refined grains.
Due to the growing prevalence, the American Cancer Society revised its guidelines in 2018, recommending colorectal cancer screenings for average-risk individuals to begin at age 45 instead of the previous age of 50. A 2017 study highlighted that individuals born around 1990 faced double the risk of colon cancer and quadruple the risk of rectal cancer compared to those born in 1950. A recent study by the Salk Institute and UC San Diego, using mice, found that high-fat diets might elevate colorectal cancer risk by impacting the gut microbiome and increasing bile acids. However, the study’s findings may not directly translate to humans due to differences in microbiomes and bile acids between species.