你的生活方式,你的基因和癌症.doc

Your Lifestyle, Your Genes and Cancer New research explores the complex interactions that cause our most dreaded disease. A look into some of the steps you can take to reduce your risk. By Robert A. Weinberg, Ph.D., and Anthony L. Komaroff, M.D. | NEWSWEEK Jun 23, 2008 Issue Weve known for a long time that a high-fat diet, obesity and lack of exercise can increase the risk of developing heart disease and type 2 diabetes, two conditions that affect millions of Americans. What we are finding out now is that those same lifestyle factors also play an important role in cancer. Thats the bad news. The good news is that you can do something about your lifestyle. If we grew thinner, exercised regularly, avoided diets rich in red meat (substituting poultry, fish or vegetable sources of protein) and ate diets rich in fruits and vegetables, and stopped using tobacco, we would prevent 70 percent of all cancers. The strongest evidence of the importance of lifestyle in cancer is that most common cancers arise at dramatically different rates in different parts of the globe. Several cancers that are extremely common in the United States—colon, prostate and breast cancer—are relatively rare in other parts of the world, occurring only 1/10th or 1/20th as often. Equally striking, when people migrate from other parts of the world to the United States, within a generation their cancer rates approach those of us whose families have lived in this country for a long time. Even if people in other parts of the world stay put, but adopt a U.S. lifestyle, their risk of cancer rises; as Japanese have embraced Western habits, their rates of colon, breast and prostate cancer have skyrocketed. What is it about our lifestyle that raises the risk of many types of cancer? The main culprits seem to be the Western diet, obesity and physical inactivity. While weve known about the importance of tobacco and cancer for more than 50 years, we are just beginning to understand how diet, a healthy body weight