An observational study of 10,469 cereal-eating physicians between 1982 and 2006 revealed that the 79 percent who ate whole grain cereals (defined for this study as at least 25 percent oat or bran content) experienced less heart failure than the 21 percent who ate refined cereals.
Those who chewed on whole grain cereal seven or more times weekly had a 28 percent reduction in risk of heart failure. Those who ate them two to six times weekly were 22 percent less likely to experience heart failure. Even a single bowl once a week lowered risk by 14 percent. The study’s lead author, Dr. Luc Djoussé of Harvard Medical School, commented, "There are good and powerful arguments for eating a whole-grain cereal for breakfast. The significant health benefits of whole-grain cereal are not just for kids, but also for adults.”
Source: American Heart Association, March 2007