A new study suggests that eating a certain common food — available in any supermarket — helps people lose weight, and may actually help reduce a person's risk of developing diabetes. What is this food? Grapefruit.

According to a pilot study of one hundred obese patients at the Scripps Clinic in San Diego, those who ate half a grapefruit with each meal lost an average of 3.6 pounds over twelve weeks, compared with a control group who lost an average of only half a pound. Some patients lost as much as 10 pounds. After the meal, the "grapefruit group" also had lower blood levels of insulin, the hormone which regulates the mechanism by which the body metabolizes sugars from food.

The more efficiently sugar is metabolized, the less likely it is to be stored as fat in the body.

Problems with this metabolic mechanism are the hallmark of diabetes. Lowering insulin levels also makes people feel less hungry. High levels stimulate the hypothalamus in the brain, which causes feelings of hunger. High insulin levels also stimulate the liver to manufacture fat that can constrict arteries, causing heart attacks and other circulatory problems.

Blood glucose levels were also lower in the grapefruit group, suggesting that they were metabolizing sugar more efficiently. The more efficiently sugar is metabolized, the less likely it is to be stored as fat in the body.

"This is the first study linking grapefruit with reduced insulin levels," says Ken Fujioka, the leader of the study group. His fellow researchers say that the weight loss is likely linked to the lower insulin level. They are considering further research to investigate whether this might of use in treating oreven preventing some types of diabetes.

Asked to comment on the study, which was published in the 2/04 issue of Chemistry & Industry Magazine, TheDoctor's Eli A. Friedman, M.D., Distinguished Teaching Professor of Medicine and Chief, Renal Disease Division of New York's Downstate Medical Center, sounded a skeptical note, saying that there have been many unsubstantiated health claims made for the grapefruit over the years, including the so−called "Mayo Diet" that has no actual connection with the Mayo Clinic. "I cannot recommend that people should increase the amount of grapefruit in their diets," says Dr. Friedman, "because there is insufficient evidence to do so. We will have to wait until a critical study is completed, reported and affirmed."

It should be noted that past studies have shown that grapefruit can affect how the body metabolizes some drugs, including common oral medications such as those taken for blood pressure, sedatives and some immuno−suppressants. Anyone taking these medications should consider discussing with their physician the issue of any interaction with grapefruit.

Reviewed by: Eli A. Friedman, M.D..