More than one million people are diagnosed with cancer in the United States each year. The link between diet and cancer is not new. In January of 1892, Scientific American printed the observation that “cancer is most frequent among those branches of the human race where carnivorous habits prevail.” Numerous research studies have since shown that cancer is much more common in populations consuming diets rich in fatty foods, particularly meat, and much less common in countries with diets rich in grains, vegetables, and fruits. One reason is that foods affect the action of hormones in the body. They also affect the strength of the immune system. While fruits and vegetables contain a variety of vitamins, minerals, antioxidants, and phytochemicals that protect the body, research shows that, by contrast, animal products contain potentially carcinogenic compounds that may contribute to increased cancer risk.
In 1997 a landmark document titled “Food, Nutrition and the Prevention of Cancer: A Global Perspective” was released by the World Cancer Research Fund and the American Institute of Cancer Research. This 670-page report by an international panel of experts reviewed more than 4,500 scientific studies and summarized the effects of diet on the most common cancer sites. These are their findings:
Increased Cancer Risk: Smoking, Alcohol use, Meat and dairy product consumption, Animal fat/saturated fat, Total fat, Grilling and barbecuing (red meat, fish, chicken), Salt and salting (e.g., as a food preservative), Obesity, Inactivity, Exposure to hazardous materials
Decreased Cancer Risk: Vegetable consumption, Fruit consumption, Carotenoids (protective substances in orange, yellow, red and green vegetables and fruits), Vitamin C, Fiber, Whole grains, Physical exercise
How powerful are these steps? Simply eating more vegetables and fruits could eliminate about 20% of cancers. By also avoiding animal products, we could easily double this number, preventing two of every five cancers. Regular exercise and maintenance of appropriate body weight can decrease cancer risk by approximately an additional 10%. Avoiding tobacco brings this figure up to roughly 70%. The remaining contributors to cancer risk include excess sun exposure, pollutants, occupational and environmental contaminants, and, to a much lesser extent (2 to 3%), genetics.
The latest studies and legal issues surrounding cancer and diet are published in Good Medicine, the quarterly magazine of Physicians Committee for Responsible Medicine. The Winter 2007 issue reports on the lawsuit filed by PCRM over carcinogens found in grilled chicken from seven chain restaurants. PCRM has gone to court under California’s Proposition 65 that states consumers must be warned about products that contain known carcinogens. The latest news is that the USDA has come to the defense of the restaurants, and not the consumer.
Source: “Healthy Eating for Life, Food Choices for Cancer Prevention and Survival” from The Cancer Project, Physicians Committee for Responsible Medicine, and Winter 2007 Good Medicine, http://www.CancerProject.org or http://www.pcrm.org