AICR’s launch of Third Expert Report – Diet, Nutrition, Physical Activity, and Cancer: A Global Perspective, came with a set of new ten Cancer Prevention Recommendations. After reviewing the vast volume of research examining the links between diet, weight and physical activity, and cancer prevention and survival, one of the recommendations from experts in the field is to be a healthy weight. It says, “Next to not smoking, maintaining a healthy weight is the most important thing you can do to reduce your risk of cancer. Aim to be at the lower end of the healthy Body Mass Index (BMI) range.”
The greater the extent of overweight and obesity, the greater the risk of cancer. Obesity affects at least one-third of Americans, raising their risk for cancer. Too much body weight is linked to at least 12 types of cancer.
AICR grantee Dr. Jay H. Fowke of Vanderbilt University is leading a study to investigate links between various measures of obesity and prostate cancer. For more than 10 years, Dr. Fowke and his colleagues have been creating a study group of high-risk patients.
These men have high-grade prostatic intraepithelial neoplasia, or HGPIN, a condition where abnormal cells line the ducts in the prostate gland. These abnormal cells may develop into tumors, although it is not known exactly how this happens or what lifestyle factors might make it more likely.
The study is considering a number of factors, body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR) and percent of body fat calculated by bioelectric impedance, where a harmless amount of electrical current is sent through the body.
Many Risk Factors to Measure
Studies of obesity and cancer are complicated by the fact that obese individuals often have other risk factors that are each known to be associated with increased cancer risk, including low levels of physical activity and exercise and diseases that are linked with increased cancer risk, such as diabetes.
In addition, Dr. Fowke explains, fat tissue in the body is thought of as “something akin to an additional adrenal gland” because it releases a number of hormones and messenger molecules into the body.
Dr. Fowke’s group is measuring the blood levels of substances that are markers of inflammation. They will look for associations between these markers, obesity and the rate at which men with HGPIN develop active prostate cancer.
Dr. Fowke says, “We think obesity affects the development of advanced prostate cancer. We don’t know why, exactly, but we think it involves inflammation.” Obesity increases the risk of disease of all types, so maintaining a healthy weight by eating a healthy diet and being physically active for at least 30 minutes each day is still the best approach to reducing one’s risk for cancer.