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In January 2017, researchers reported that exercise is associated with a lower risk of death from metastatic colorectal cancer. Metastatic colorectal cancer is cancer of the colon or rectum that has spread to other areas of the body. This study found people who were physically active for four or more hours per week reduced their risk by 20 percent. People who exercised for at least five hours per week lowered their risk by 25 percent.
These results reinforce other data researchers have collected on how exercise affects the risk of colorectal cancer. Though we don’t fully understand why, exercise plays a role in the development of colorectal cancer—for people who may be at risk for the disease, people who already have it and people who have been treated for it.
Who’s at risk for colorectal cancer?
Several lifestyle factors can increase the risk for colorectal cancer, including:
- Diets high in red meat, such as beef and pork
- Diets high in processed meats, such as hot dogs and bologna
- Heavy alcohol use
- Obesity, particularly excess belly fat
Other factors can also increase the risk of developing colorectal cancer. These include:
- A history of inflammatory bowel disease, including Crohn’s disease and ulcerative colitis
- Family history of colorectal cancer or colon polyps (growths in the colon)
- Being African-American
- Having type 2 diabetes
Colorectal cancer tends to affect people in older age groups. That’s why we recommend people over 50 get a colonoscopy on a regular basis to lower their risk for colorectal cancer. Your doctor may recommend starting earlier if you have one or more of the above risk factors. For instance, we recommend African-Americans start getting regular colonoscopies at age 45. Though there are other tests available to screen for colorectal cancer, colonoscopy is still the best option for finding and treating the disease as early as possible.
Getting active to stay healthy
As we age, we tend to be less active and at higher risk for conditions like heart disease and diabetes, which can further limit our activity levels. But even a little exercise every week can lower your risk of colorectal cancer. Studies cited by the National Cancer Institute have found adults who increase their physical activity can reduce their risk of developing colorectal cancer by 30 to 40 percent compared to people who don’t exercise. That’s on top of the benefit researchers have found exercise has in people whose cancer has spread.
Modest amounts of moderate exercise can help. I tell patients that if they’re breaking a sweat for about 20 minutes at a time two to three times a week, that seems to be enough. Walking is a great way to do this. Some other examples of moderate exercise, according to the Centers for Disease Control and Prevention (CDC), include:
- Climbing stairs or using a stair climber
- Playing basketball
Research shows that people don’t have to do intense exercises to get these survival benefits. When it comes to lowering your risk of colorectal cancer, just getting up and doing something is important. If you can do more, that’s great! If you can’t, do what you can. Just make sure you’re doing something. And talk to your doctor about starting any new exercise plan, especially if you have conditions like heart disease, lung disease, diabetes or other serious conditions.
Exercise even helps after a patient has had surgery to treat colorectal cancer. The American Cancer Society notes that people who exercise regularly after being treated for colorectal cancer have a lower chance of the disease coming back, as well as a lower chance of dying from the disease. In addition, exercise has been linked to an improved quality of life and less fatigue after colorectal surgery. If you’re starting or resuming an exercise routine after colorectal surgery, be sure to talk to your doctor beforehand about the types of exercise you can do safely.
Controlling your colon cancer risk
I realize that getting active is easier for some people than others. By the time people are in their 60s and 70s, if they haven’t exercised regularly before, making that sort of lifestyle change can be tough. But I encourage my patients to do what they can to lower their risk for colorectal cancer. I let them know that even little changes in their activities or walking just a little bit can benefit them in the long term.
Older adults who have never exercised before may not know where to start. It can be intimidating to walk into the local gym and get started on a fitness plan. The National Institute on Aging has examples of sample exercises for older adults based on four key fitness areas: endurance, strength, balance and flexibility. Your doctor can also provide guidance on the types and amount of exercise you should do.
And exercise isn’t the only thing I advise people do to lower their risk. Other ways you may be able to reduce the risk of colorectal cancer include:
- Limiting red and processed meat in your diet
- Eating more fruits, vegetables and whole grain
- Avoiding excess alcohol
- Eating a low-glycemic-index diet
Take the first step
We need more research in this area of medicine to find out exactly why exercise lowers the risk of death from colorectal cancer and the risk of developing it in the first place. For now, though, the data show a clear link between the disease and activity levels.
You don’t have to live at the gym or train for marathons to reduce your risk for colorectal cancer. Take a brisk walk around the block once a day, or watch your favorite TV show while you walk on the treadmill. Every step is one you’re taking to live a healthier, more active life—and one free from colorectal cancer.