As with all diseases, prevention is the best medicine when it comes to colorectal cancer.
Colon cancer and rectal cancer, typically grouped together as colorectal cancer because they are both diseases of the large intestine, affect approximately 1 in 20 Americans.
Colorectal cancer is the fourth most common cancer in the United States (excluding skin cancers) and the second most common cause of cancer-related death, after lung cancer. The National Cancer Institute estimates that around 140,000 people in the United States will be diagnosed with colorectal cancer each year.
Effective prevention, therefore, has a huge potential to improve the health both of individuals and the public as a whole.
Here are the most powerful ways to prevent colon cancer and rectal cancer.
1. Stay at a Healthy Weight
Men and women who are overweight or obese are more likely to develop colorectal cancer.
The danger seems to be especially high for men, especially those who amass extra pounds around their midsection.
Rising obesity rates in the United States also seems to be linked to increasing rates of colorectal cancer among younger people.
A study published in October 2018 in the journal JAMA Oncology tracked the health of over 85,000 women for 22 years and found that the higher a woman’s body mass index (BMI), the greater her risk of developing colorectal cancer before age 50. (1)
The study found that women ages 20 to 49 who were considered overweight or obese had up to twice the risk of developing early-onset colorectal cancer, compared with women who reported the lowest BMIs.
RELATED: The Anti-Cancer Diet: Foods That Prevent Cancer
2. Exercise More — the Harder, the Better
Regular, moderate exercise — exercise that slightly increases your heart rate — such as brisk walking, lowers the risk of colon cancer and rectal cancer.
But vigorous exercise appears to offer the biggest benefit.
A National Cancer Institute study of over 1.4 million people, published in June 2016 in the journal JAMA Internal Medicine, found that higher levels of physical activity, compared with lower levels, were associated with a 16 percent lower risk of colon cancer and a 13 percent lower risk of rectal cancer. (2)
The American Cancer Society offers tools to help people who want to become more physically active, including a target-heart-rate calculator that helps you determine whether you are reaching workout goals.
Related: 10 Amazing Benefits of Exercise
3. Rethink Your Diet (Hint: Up Produce Intake)
Numerous studies have confirmed that diet plays a role in many colorectal cancers.
Eating red meat (beef and lamb) and certain processed meats (such as sausage and hot dogs) seem to raise colorectal cancer risk, so it makes sense to limit these foods. Diets that are high in fruits and vegetables seem to lower colon and rectal cancer risk. To prevent disease, up your intake of produce.
A number of large studies have suggested that dietary fiber can reduce colorectal cancer risk. Researchers are continuing to explore this connection.
RELATED: What Is the Best Diet for Cancer Prevention?
4. Avoid Drinking Alcohol to Excess
Moderate to heavy alcohol use has been linked with a higher risk of cancers of the colon and rectum.
Evidence for this is generally stronger for men than women, but studies have found a connection in both sexes.
The American Cancer Society suggests limiting alcohol to two drinks a day for men and one for women. (3)
5. Don’t Pick Up a Cigarette
Most people know that cigarette smoking raises lung-cancer risk but are less aware of its connection to colon cancer and rectal cancer.
6. Take Aspirin or Another Nonsteroidal Anti-Inflammatory — but Only With a Doctor’s Okay
There is good evidence that people who take aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Motrin, Advil) and naproxen (Aleve), lower their risk of colorectal cancer.
Still, it’s necessary to balance the potential benefits with the possible side effects, some of which are quite serious, such as stomach ulcers.
Physicians generally do not recommend NSAIDs to patients who are at average risk. Talk to your doctor to see if you are a good candidate for these medicines.
RELATED: Risks of Daily Aspirin Use May Outweigh Benefits in Healthy Older People
7. Have Regular Colon Cancer Screening
Screening tests aim to identify colorectal cancer in individuals who don’t have typical symptoms, such as bloody stool or abdominal pain.
They may be able to spot colorectal cancer at its early stages and can identify precancerous colorectal polyps (abnormal growths). There are two kinds of screening tests: stool-based tests and visual exams.
Stool-based screening tests analyze feces samples for occult (hidden) blood or abnormal sections of DNA. Samples are fairly easy to collect at home and return to a doctor’s office or medical lab. But testing must be done fairly frequently, even as often as every year.
There are a number of different colorectal visual exams, but the gold standard is colonoscopy. During this procedure, while a patient is sedated, doctors examine the inside of the colon and rectum via a device inserted through the anus: a long, flexible tube with a tiny video camera at the end. Prior to this procedure, patients need to clean out the colon and rectum, a process that involves drinking a powerful laxative solution.
During a colonoscopy, doctors can remove and biopsy any polyps they find, leading to a determination of whether a growth is cancerous, precancerous, or benign.
Removal of polyps detected through screening is one reason colorectal-cancer death rates have been dropping over the past few decades.
Colorectal screening also offers the advantage of detecting and treating colorectal cancer while it is still localized, meaning it hasn’t spread beyond the large intestine. Cancer caught and treated in this early stage has a five-year survival rate of roughly 90 percent.
Unfortunately only a little more than one-third of colorectal cancers are identified at this stage. One of the problems is that many people who should be undergoing screening tests aren’t having them.
The U.S. Preventive Services Task Force, which sets policy for Medicare and private insurers under the Affordable Care Act, recommends that colorectal screening for people at average risk begin at age 50.
But in May 2018, the American Cancer Society revised its guidelines and shifted its recommendations from 50 to 45, after a review of data showing increasing incidence of the disease among younger people.
In an article published in June 2017 in the American Journal of Gastroenterology, the American College of Gastroenterology suggested that African Americans at average risk begin screening at age 45 because of high rates of colorectal cancer in this group. (4)
People who are considered at high risk, such as those with a family history of the disease, who have a prior history of cancer or polyps, or who carry certain known genetic mutations known to increase cancer risk, may also want to start screening at an earlier age. A physician can help people with these kinds of histories decide on an appropriate age for screening.
One advantage of colonoscopies is that they can be done far less frequently than stool-based tests. People at average risk generally need be screened this way only once every 10 years.