A bowl a day of whole-grain cereal reduces risk of heart failure by 28 percent; a bowl every week by 14 percent, according to a study recently published in the Archives of Internal Medicine. Brigham and Women's Hospital and Harvard Medical School researchers Luc Djoussé, MD, MPH, DSc, and J. Michael Gaziano, MD, MPH, evaluated the association between whole-grain breakfast cereal intake and the incidence of heart failure among more than 21,000 participants from the Physicians' Health Study I.

This, the first study to specifically establish an association between breakfast cereal and reduced risk of heart failure, also stated that heart failure is the leading cause of hospitalization among the elderly population in the United States. The FDA allows a whole-grain claim on foods containing at least 51 percent whole grains by weight that are low in fat and saturated fat. But the study classified cereals with at least 25 percent whole grains or bran by weight as whole-grain. The primary dietary mechanisms contributing to the benefits of whole-grain cereals include slower digestion and satiety.

"It has to be whole-grains—anything containing 4 or more grams of fiber per serving," said Djoussé. "The transit of whole grains through the digestive tract is slower, and the release of glucose into the blood stream is slower. Consequently you are less likely to be hungry shortly after eating whole grains, and therefore less likely to gain weight or develop insulin resistance, thereby avoiding some of the major risks for heart failure." Additional benefits include the LDL cholesterol-lowering properties of fiber and the blood pressure-lowering effects of the minerals potassium and magnesium found in whole grains.

But Djoussé was careful to say a breakfast bowl of bran by itself is no panacea. It's just one part of maintaining a healthy diet and lifestyle. "Anyone eating whole grains also needs to avoid other heart health risks such as smoking and consuming trans fats," Djoussé said. "They also need to exercise regularly and stay on blood pressure medicine if they have high blood pressure."

Djoussé also cautions against over-eating whole grains or diluting the effects with refined carbohydrates. "Watching calories is important too," said Djoussé. "We recommend half a cup to one cup per serving, but not more than that. It's also important to use skim or low-fat milk and not add any refined sugars because they negate any potential benefits of the whole grains. People who like a sweetened taste can add a piece of fruit but not refined sugars."