Vegetables Fight Diabetes and Colon Cancer

Two studies in the December 2003 American Journal of Clinical Nutrition add more evidence against fatty meats, dairy products, and eggs, while supporting the health value of vegetable-rich diets. In the first report, Michigan State University researchers analyzed data from the third National Health and Nutrition Examination Survey, conducted by the Centers for Disease Control and Prevention. They identified two prevalent dietary patterns: One, which they termed the “Western” pattern, was heavy on processed meats, eggs, red meats, and high-fat dairy products, while the other, called the “American-healthy” pattern, emphasized green, leafy vegetables, salad dressings, tomatoes, other vegetables (e.g., peppers, green beans, corn, and peas), cruciferous vegetables, and tea. Blood tests showed that the more people followed the “Western” pattern, the more problems they had with blood-sugar control. They had higher blood concentrations of glycosylated hemoglobin, insulin, and C-peptide, and lower concentrations of folic acid.

In the second report, the antioxidant lycopene showed power to prevent colon cancer. Lycopene is the red pigment in tomatoes, watermelon, pink grapefruit, pink guava, and papaya. Researchers in Stuttgart, Germany, studied people undergoing colonoscopy, and compared those whose colon examinations turned out to be normal to those whose examinations revealed adenomatous polyps—the kind that often lead to colon cancer. Those with the precancerous growths had, on average, 35% lower blood levels of lycopene, as well as somewhat lower blood levels of beta-carotene. The results suggest that loading up on healthy fruits and vegetables, especially lycopene-rich varieties, can help prevent colon cancer. Previous studies have linked lycopene to reduced risk of cancers of the prostate, lung, and stomach.