9 Colorectal Cancer Risk Factors You Can Control—and 7 You Can’t
Updated: Mar. 07, 2019
While colon cancer is the second most commonly diagnosed cancer in Canada, it's often preventable—if you know how to reduce your risk.
You can control obesity
Over five million Canadian adults have obesity, according to statistics from Obesity Canada. Along with heart disease and diabetes, these conditions are directly linked to an increased risk of colon cancer. “Studies have shown that as countries have more Western diets, their rates of colon cancer increase,” says Heather Yeo, MD, colon and rectal surgeon at Weill Cornell Medicine. While obesity can be hard to control, it is possible with the help of medical and surgical intervention to manage weight. These are the 10 most common types of cancer in Canada.
You can’t control your family history
Family history and genetics account for about 15 percent of patients with colon cancer, according to Anton Bilchik, MD, PhD, professor of surgery and chief of gastrointestinal research at John Wayne Cancer Institute at Providence Saint John’s Health Center in Santa Monica, California. For this reason, any individual who is diagnosed with colon cancer under age 50 should undergo a workup for the presence of these genetic mutations. “These tests are simple to perform and easily available by performing a blood test,” Dr. Bilchik explains. “If the gene is present, then closer surveillance is needed for family members.” Always keep in mind, these spots are common to ignore when checking for cancer.
You can control your fibre intake
Diets high in fibre from fruits, vegetables, whole grains, nuts, and legumes can be protective against colorectal cancer. “Soluble fibre, which is fermented by gut bacteria, leads to the production of short-chain fatty acids like butyrate, which have anti-cancer properties in the colon,” explains Shilpa Ravella, MD, gastroenterologist and assistant professor of medicine at Columbia University Medical Center. She recommends including as much fibre in your diet from whole plant foods as possible. Find out which 15 foods have the ability to detox your body naturally.
You can’t control a family history of colorectal polyps
A third of patients diagnosed with colorectal cancer have a family member with a history of colorectal cancer or colorectal polyps, according to Samir R. Shah, MD, colorectal surgeon at Lexington Medical Center in West Columbia, South Carolina. “Generally you want to start the screening process ten years prior to the youngest age of the affected family member,” he says. “If you’ve ever had polyps, your risk of colorectal cancer is higher than an individual without any history of polyps, so it is crucial to continue surveillance with regularly scheduled colonoscopies or accepted forms of screening.” Don’t miss 15 cancer symptoms women are likely to ignore.
You can control the red and processed meat in your diet
Research links a diet high in red and processed meats to an increased risk of colorectal cancer. “Heme iron, nitrates, nitrites, and other potential carcinogens found in meats that have been pan-fried, barbecued, seared, and cooked at high temperatures—including beef jerky, corn beef, ham, bacon, sausage, and other cured meats—are the cause,” says Cedrek McFadden, MD, colorectal surgeon and clinical assistant professor of surgery at the University of South Carolina School of Medicine Greenville. “It should be noted, however, that this absolute risk of consumption of red and processed meat is small and only occurs with the daily consumption of these foods.” In other words, most experts say you should limit your servings to one to two a week.
You can’t control your age
Like most diseases, colorectal cancer risk increases as you age. The likelihood of a diagnosis increases after the age of 40 and rises sharply after age 50, says Eyal Meiri, MD, interim chief of medical oncology at Cancer Treatment Centers of America in Atlanta. “The concern of late, however, has been the increasing incidence of colorectal cancer in young adults,” he says.
You can control whether or not you smoke
Cigarette smoking is responsible for a myriad of illnesses, many of which are fatal, and colorectal cancer is one of them. In fact, research shows that the risk of colon cancer jumps 19 percent in women smokers and 8 percent in male smokers. “Some studies show even a few cigarettes a day can increase your risk for colon cancer, let alone other malignancies, so just don’t start,” says Dr. Shah.
You can’t control a history of inflammatory bowel disease
“Those suffering from inflammatory bowel disease (IBD), including Crohn’s disease or ulcerative colitis, tend to have chronic inflammation in their colon and intestines, which can increase the risk of colorectal cancer,” says Dr. Ravella. “The increase in the risk of colon cancer begins several years after the initial diagnosis and is especially pronounced in patients with large areas of the colon affected, the longest disease duration, and in those with active inflammation.” For this reason, all patients with IBD should talk to their gastroenterologists about when to start screening for colon cancer. Plus, don’t miss these 10 rampant cancer myths you need to stop believing.
You can control how much alcohol you drink (and how often)
Too much alcohol is another vice that can have severe health consequences including colorectal cancer. One analysis of studies found that heavy drinkers raised their colorectal cancer risk by 37 percent compared to non-drinkers, and even light drinkers had a 7 percent increase in risk. “Particularly, alcohol use is associated with younger onset of colorectal cancer that is usually found in the left side of the colon,” says Dr. Meiri.
You can control how often you eat garlic and onions
Allium, a substance found in garlic, onions, shallots, chives, scallions, and leeks seems to lower the risk of colorectal cancer, likely by defusing carcinogens and interrupting blood supply to tumours. Research published in the Asia-Pacific Journal of Clinical Oncology matched 833 people with the cancer to the same number of healthy people of about the same age, sex, and other demographics. After comparing diets, the researchers found that people who ate plenty of allium-containing vegetables had 79 percent lower risk of colorectal cancer, compared to those whose diets were largely allium-free. “It is worth noting that in our research, there seems to be a trend: The greater the amount of allium vegetables, the better the protection,” said senior author Dr. Zhi Li of the First Hospital of China Medical University in a news release. Load up on these other 22 foods proven to help fight cancer.
You can’t control your race and ethnicity
“African Americans have the highest risk of developing and dying from colorectal cancer, with a 20 percent higher mortality, as well as a higher stage of disease at presentation,” says Dr. McFadden. “I suspect these differences are related to genetics or more aggressive tumour biology and/or lower rates of screening.” Additionally, he points out that with many doctors believing this is a disease of “older white men,” many African Americans may not learn preventive strategies. The recommendation for African Americans is to begin screening colonoscopies at 45 years of age.
You can control your physical activity level
The U.S. Department of Health and Human Services recommends that adults get at least 150 minutes of moderate physical activity a week—a goal that too few of us reach on a consistent basis. As Dr. McFadden points out, people who are more physically active lower their risk of colorectal cancer and their chances of developing breast cancer, heart attacks, diabetes, and stroke. “This increase in physical activity tends to also reduce obesity, which also can reduce the risk of colorectal cancer,” he adds. Make sure you know these 5 exercise strategies to reduce your risk of injury.
You can’t control your transplant status
According to Dr. Ravella, patients who have received an organ transplant, such as a kidney, can have a higher risk of developing colorectal cancer because of the risks that come with long-term use of drugs that suppress immunity. For this reason, she recommends that such patients discuss more frequent screening with their gastroenterologist.
You can control your aspirin use
In recent years, the U.S. Preventive Services Task Force has found the practice of taking daily aspirin can reduce the risk of colorectal cancer by 40 percent in high-risk patients. However, Dr. Yeo points out that aspirin can increase the risk of gastric bleeding—yet patients need to use it consistently for long periods of time to show improvement. Discuss your colorectal cancer risk and potential side effects of aspirin with your doctor before taking it routinely. You should also reconsider your habits if you’ve been doing these things you think prevent cancer—but don’t.
You can’t control exposure to abdominal radiation as a child
Childhood cancer survivors who got radiation treatment can be at increased risk of colorectal cancer, notes Dr. McFadden. “An increase in risk is also seen in patients who have had radiation for treatment of prostate cancer or cervical cancer,” he says. “This finding leads to recommendations to begin screening for colorectal cancer… at a young age in these patients (either ten years after radiation or at the age of 35).”
You can control getting screened
Experts believe that screening is one of the most important things people can do to reduce their colon cancer risk. “There are a number of screening tests, including colonoscopy and stool-based tests, that are available,” says Sonia Kupfer, MD, internist and gastroenterologist at the University of Chicago Medical Center. The Canadian Cancer Society recommends that individuals aged 50 to 74 years old have a stool test done every 2 years. In the meantime, check out which Canadian provinces have the highest cancer rate.
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