Your metabolic phenotype is how your body takes in and uses energy; it affects many aspects of health, including the risk of colon cancer in women. Here’s why.
Obesity is often associated with an increased risk for developing cancer. But according to a study from the Beijing Normal University in China, an unhealthy metabolism can risk colon cancer in women after menopause, even if they are a healthy weight.
The research found that postmenopausal women with a normal weight (measured by a body mass index of 18.5 to 24.9) and an unhealthy metabolic phenotype were nearly 50 percent more likely to develop colorectal cancer than those with a healthy metabolic phenotype.
What is metabolic phenotype?
Your metabolic phenotype is how your body takes in and uses energy, and it affects many aspects of health. Phenotype is influenced by a variety of factors, including genetics, environment, lifestyle, and the bacteria that live in your digestive system.
Though many things affect your phenotype, it is often measured based on features that can be observed, including body mass index, appearance, behavior, diet, glucose levels, and blood pressure.
Individuals are often considered to have metabolic syndrome if they have three or more of either high waist circumference, elevated blood pressure, elevated levels of triglycerides, high glucose levels, and low levels of healthy cholesterol. In the Beijing study, participants were placed in the unhealthy phenotype group if they had two or more of any of those conditions except high waist circumference.
Metabolic phenotype and colorectal cancer
The Beijing study, which was led by Xiaoyun Liang, MD, PhD, looked at over 5,000 postmenopausal women with a healthy weight, 33.7 of whom were considered metabolically unhealthy. After a mean follow-up time of 14.3 years, the metabolically unhealthy women were 49 percent more likely to develop colon cancer than the metabolically healthy group. They also found that women with metabolic syndrome had a twofold higher risk for colon cancer than those without metabolic syndrome.
“Even though poor metabolic health is usually associated with obesity, 30 percent of normal-weight adults are believed to be metabolically unhealthy worldwide,” says Liang. “Our finding that normal-weight U.S. women who are metabolically unhealthy have an increased risk of colorectal cancer… highlights how important it is for women to be aware of their metabolic health status, which can be assessed using standard clinical tests.”
Colorectal cancer includes colon, rectal, and rectosigmoid cancers. Which type is diagnosed depends on where in the body the cancer initially develops, though all three are related and many people will develop multiple forms of colorectal cancer as the disease progresses.
Colorectal cancer is the third most commonly diagnosed form of cancer for both women and men in the United States, according to the Centers for Disease Control and Prevention. It is also the second leading cause of cancer-related deaths in the U.S. Out of every 100,000 American women, 33.6 will develop some form of colorectal cancer in their lifetimes, and for 12.1 of those women it will be fatal.
Liang notes that her research had some limitations. Participants’ body mass index and metabolic health were measured only at the beginning of the study, so any changes that occurred were not taken into account in the results. The findings are also specific to postmenopausal women and cannot be generalized to apply to younger women or to men.
Still, Liang hopes the study’s results will help doctors identify women at risk for colorectal cancer early enough to reduce the number of lives the disease claims. “Recognition that normal-weight women who are metabolically unhealthy may have an increased risk for colorectal cancer,” she adds in the press release, “could result in more timely use of preventive interventions and reduce the burden of this deadly disease.”
Talking to your doctor about cancer risk
Identifying colorectal cancer early can prevent the disease from becoming fatal. This is usually done with a colonoscopy, a minimally invasive procedure that can find both tumors and precancerous polyps in the colon and rectum.
If you are a postmenopausal woman who shows signs of an unhealthy metabolism — including elevated fasting glucose, high blood pressure, or unhealthy cholesterol levels — you may want to talk to your doctor about your risk for colorectal cancer even if you are a healthy weight. Your doctor can order a colonoscopy for screening or advise you on lifestyle changes that will reduce your risk of developing cancer.
May 09, 2017
Janet O’Dell, RN