Colorectal cancer has long been one of the more common types of cancer in both men and women in the United States, but, in recent years, it’s become alarmingly more prevalent. While the overall incidence of advanced-stage colorectal cancer has increased by eight percent from the mid-2000s to 2019, it’s jumped up 20 percent among people under 55, according to a recent study published by the American Cancer Society.
Colorectal cancer describes cancer of the colon (large intestine) and cancer of the rectum (the terminal end of the gastrointestinal tract located just before the anus), explains Kevin E. Woods, M.D., M.P.H., chief of Interventional Endoscopy, Gastroenterology and Nutrition at the City of Hope Cancer Center in Atlanta. “Colorectal cancer occurs when abnormal polyps form in the colon and/or rectum and develop into cancer over time,” he says. “We believe that, when healthy cells that line the colon become damaged or changed, mutations in their cell programming (DNA) create an environment for continued cellular growth in which the damaged cells are unable to stop dividing and form a precancerous polyp.” As the polyp grows, these cells can spread out and travel to other parts of the body.
A number of factors are known to increase the risk of this particular type of cancer. For example, persons of African American descent are more than 20 percent more likely to get colorectal cancer and about 40 percent more likely to die from it than other racial and ethnic groups, according to the American Cancer Society.
Some genetic variables, such as having the BRCA gene, familial adenomatous polyposis (FAP), or Lynch syndrome (hereditary nonpolyposis colorectal cancer), can also impact your risk. Family history, of course, is also a factor.
Patients with a history of inflammatory bowel disease (like large bowel Crohn’s disease or ulcerative colitis) also have a higher risk of developing colorectal cancer.
- ABOUT OUR EXPERTS: Andrew Moore, M.D., is a Chicago-based gastroenterologist. Rabia de Latour, M.D., is a double board-certified gastroenterologist and therapeutic endoscopist in New York City.
Why The Rise In Colorectal Cancer?
Given that colorectal cancer is generally considered to be a preventable disease, it’s alarming to see an increase in diagnoses and deaths, suggests Woods. Here, he and other gastroenterologists share their theories about why colorectal cancer is on the rise—and what to do to minimize your risk.
More older adults are getting screened—but younger adults are not.
“What we’ve seen since the early 1990s is an overall decrease in the incidence and mortality of colorectal cancer in older adults, which is largely due to the use of colonoscopy as a tool for both screening and prevention,” says Chicago-based gastroenterologist Andrew Moore, M.D. “Unfortunately, for adults under the age of 50, we’re seeing the opposite trend; the incidence of colorectal cancer among adults younger than 50 has nearly doubled since the mid-1990s.”
Also troubling: Since younger adults don’t fit the typical requirements that warrant earlier screenings, they’re more likely to be diagnosed with later-stage cancer, he says.
“If you do not have a family member in the first degree (mother, father, siblings, or children) with a history of colon polyps or cancer, you are considered average risk, which means you should be screened for the potential of a colon polyp or cancer at age 45,” Moore says. If you have a family history of colon cancer or carry any genes that increase your risk, advocate for earlier screenings. Typically, you’d start at age 40, or 10 years younger than the age of your youngest affected relative when diagnosed.
Obesity rates are increasing
One of the biggest risk factors for colon cancer, as well as many other types of cancer, is being overweight or obese. Unfortunately, nearly one in three (30.7 percent) and more than two in five (42.4 percent) of U.S. adults are overweight and obese respectively, according to data from the National Institutes of Health (NIH). “In the southern and midwestern United States, where we see the highest increases in early-onset colorectal cancer, there are also higher rates of obesity,” says Moore.
The connection here: “Obesity is linked to chronic inflammation and insulin resistance, both of which can promote the development of cancerous growths in the colon,” Moore says.
We’re eating more processed foods than ever
An ever-growing body of research has linked ultra-processed food to chronic illnesses, including cancer. For example, one study published in The American Journal of Clinical Nutrition found that increased highly processed food consumption was correlated to higher risks of obesity, heart disease, metabolic syndrome, and some cancers, including colon cancer.
Read More: ‘I Cut Out Added Sugar For 2 Weeks—Here’s What Happened’
One possibility here is that previous generations exposed to processed foods may have acquired genetic mutations that were then passed down to the current generation and are now contributing to this increase in colorectal cancer rates among young adults, Moore says.
Antibiotic use Is Off the Charts
Breakthrough research is starting to uncover a potential link between oral antibiotic use early in life and increased incidence of colorectal cancer at a younger age. The study, published in the British Journal of Cancer, looked at data from nearly 30,000 people and suggested that antibiotics may play a role in tumor formation in the colon. “While the mechanism is not entirely clear, it may be related to changes in the gut microbiome that result from antibiotic use,” says Moore. This is quite concerning, especially considering that global antibiotic consumption rates increased by 46 percent between 2000 and 2018. (Thankfully, you can take steps to support your gut while taking antibiotics, such as incorporating a high-quality probiotic supplement, getting plenty of rest, and minimizing sugar and processed foods.)
Access to healthcare is limited for many Americans
Unfortunately, disparities in access to healthcare and screening services are prevalent in the United States—and may be contributing to higher colon cancer rates in certain populations, explains Woods. For example, Black patients have a near-20 percent higher incidence of colorectal cancer, according to research published in the journal Surgical Oncology Clinics of North America—and this is due, in part, to a lack of access to quality healthcare. “Individuals with limited access to preventive care may be less likely to undergo screening or receive timely diagnosis and treatment for colorectal cancer,” he says.
How to reduce your colon cancer risk
Currently, average-risk patients have a four percent lifetime risk of developing colorectal cancer. And while this disease can affect anyone, there’s a lot you can do to lower your risk.
Clean up your plate
You know a healthy diet is important, but may not realize how intrinsic it is to reducing your risk of heart disease, type 2 diabetes, obesity, and several cancers (including colorectal cancer!), per the CDC. Start by focusing on eating a balanced diet rich in fruits, vegetables, whole grains, and lean proteins.
Rabia de Latour, M.D., a double board-certified gastroenterologist and therapeutic endoscopist in New York City, specifically recommends eating a diet high in fiber and low in saturated fats to promote digestive health and reduce inflammation. If you struggle to get enough fiber onto your plate, consider incorporating a fiber supplement. (Here are a few signs you’re falling short—plus helpful tips for making supplementing more enjoyable.)
It’s also wise to reduce your intake of known carcinogens such as red and processed meats, in addition to sugary foods and refined carbohydrates, which may increase insulin resistance, the CDC recommends.
Move more
Regular exercise—ideally the recommended 150 minutes per week, or about 30 minutes a day—can also lower your risk by helping you maintain a healthy weight and improving your digestion, notes Moore.
Read More: 14 Ways To Mix Up Your Favorite Workout Moves
Mind your vices
If you’re a smoker or frequent drinker, consider curbing these behaviors as much as possible. Excessive alcohol consumption (which is four or more drinks for women and five or more for men on a single occasion) is linked to an increased risk of colorectal cancer, per research from the Colon Cancer Foundation. Smoking, meanwhile, is associated with an increased risk of various types of cancer, colorectal cancer included.
Get screened
Last but not least, stay up-to-date with recommended colon cancer screenings. As noted earlier, average-risk individuals should start screenings at age 45. If you have a family history of colon cancer or advanced polyps, begin at age 40, or 10 years before the age of the immediate family member when they were diagnosed.
“Colonoscopy is very effective for both detecting and preventing colorectal cancer,” Moore says. “Those who get colonoscopies at the recommended screening intervals have a significantly reduced risk of developing colorectal cancer.”