Q. Dear Dr. Baskett: I have heard about connections between obesity and cancer. Is there a relationship between the two?
A. Actually, studies do show growing evidence of a link between increased body weight and the risk for certain types of cancers. This does not mean an obese person will, with certainty, develop cancer.
However, there does appear to be a relationship between obesity and uterine, esophageal, kidney, colon, prostate, pancreatic and postmenopausal breast cancers.
For cancers of the breast, uterus and colon, the increase in cancer risk from obesity may be due to alterations in the metabolism of androgens, estrogens, and progesterone as well as insulin and insulin-like growth factor. The sex steroid hormones are known to regulate the balance between cellular differentiation, proliferation and apoptosis. In other words, these hormones affect how the cells grow, develop and die.
Remember, a consequence of obesity can be insulin resistance, which leads to an increase of insulin from the pancreas. Chronically higher levels of insulin and insulin-like growth factor inhibit cell apoptosis, which plays a crucial role in maintaining health by eliminating old, unnecessary and unhealthy cells. The human body replaces about a million cells each second. When programmed cell death does not work correctly, cells that should be eliminated hang around.
These older cells have greater potential to develop into cancerous cells.
Obesity increases the risk for developing gastro-esophageal reflux, otherwise known as heartburn. Chronic reflux can result in Barrett’s esophagus, a precursor for esophageal cancer.
The proportion of esophageal cancer cases secondary to reflux has been estimated to be more than 50 percent, and it increases with the intensity of symptoms of reflux.
So, it’s important to maintain a healthy weight and body composition for many reasons. One important caveat — BMI alone can be misleading. The ratio between lean body mass and adipose (fat) tissue can vary significantly between individuals with the same BMI. The ultimate goal is to have a lower BMI and little visceral fat. Work to achieve a healthy body weight and composition through appropriate calorie intake and regular exercise.
Your life depends on it.
Dr. Kathleen T. Baskett is medical director of the St. Vincent Healthcare Weight Management Clinic and author of “Moving Forward: The Weigh to a Healthier Weight.”