Diets High in Fat and Cholesterol May Raise Breast Cancer Risk

Previous studies have suggested that diet and obesity are important risk factors for cancer development. Philippe G. Frank, from Thomas Jefferson University (Pennsylvania, USA), and colleagues examined the role of fat and cholesterol in breast cancer development. The researchers utilized the PyMT mouse model, which is believed to closely parallel the pathogenesis of human breast cancer, to determine the role of dietary fat and cholesterol in tumor development. The team placed PyMT mice on a diet that contained 21.2% fat and 0.2% cholesterol, reflective of a typical Western diet. A control group of PyMT mice was fed a normal diet that included 4.5% fat and negligible amounts of cholesterol. Among the mice fed the fat/cholesterol-enriched chow, tumors began to develop quickly, the number of tumors was almost doubled, and they were 50% larger, as compared to the mice fed the normal chow.  To confirm the aggressive nature of the cancer in animals fed a cholesterol-rich diet, the researchers examined the levels of several biomarkers of tumor progression and found a signature of a more advanced cancer stage, compared to tumors that developed in the control group. Positing that: “These data provide new evidence for an increased utilization of cholesterol by tumors and for its role in tumor formation,” the researchers conclude that: “These results imply that an increase in plasma cholesterol levels accelerates the development of tumors and exacerbates their aggressiveness.”