Nutrition News: Weight and Cancer Risk
We all know being overweight or obese isn't healthy. In fact, most of us have tried - at some point in our lives -- to shed a few extra pounds. A recent look at weight and its effect on cancer should encourage all of us to keep trying.
Many people think that whether or not you get cancer is just luck of the draw. Or, that your chances are determined by genes you inherit from your parents. Being overweight or obese increases the risk for several types of cancer, including cancers of the colon, rectum, endometrium, liver, kidney, breast (in postmenopausal women), gallbladder, pancreas, and some parts of the stomach, ovary and esophagus. Obesity also raises the risk for developing advanced prostate cancer, according to Dr. Anne McTiernan with the Fred Hutchinson Cancer Research Center, Seattle, Wash.
But the good news is that some of these so-called "obesity-related" cancers can be prevented. It's never too late to reduce your risk for these cancers. When researchers followed people who intentionally lost weight, they discovered that weight loss reduced risk for breast and other cancers, particularly in women.
Tiermann and colleagues conducted a series of clinical studies, assigning people by chance to weight loss diets, exercise programs, or control groups. They found that reducing weight through either diet or exercise significantly lowers the following cancer risk factors:
--Estrogens and testosterone, which are risk factors for breast and endometrial cancers.
--Inflammation-related proteins, which increase risk for colon and other cancers.
--Proteins that control growth of blood vessels. By lowering these, tumors would have less nourishment to grow.
--Insulin, glucose, and related metabolic factors, which if left unchecked, cause overgrowth of many cells including tumor cells
--Oxidative stress, which results in normal cells being attacked, possibly inciting a cell to turn cancerous.
--Proteins made in fat tissue, which have been associated with increased cancer risk.