Use glycemic index to help control blood sugar

P.J. Skerrett, Managing Editor, Harvard Health

A diabetic should know Glycemic index (GI). Even if you aren’t, know about GI as low glycemic index diets have been linked to reduced risks for cancer, heart disease, and other conditions. Glycemic index rates carbohydrate-containing foods by how much they boost blood sugar (blood glucose).

Carbohydrates are the main nutrient in bread, pasta, cereals, beans, vegetables, and dairy foods. All carbs are made up of sugar molecules. carbohydrate-containing food affects blood sugar depending on its sugar content and on how quickly the digestive system breaks the food into sugar molecules. The glycemic index measures how well a food boosts blood sugar compared to pure glucose. A food with a glycemic index of 30 boosts blood sugar only 30% as much as pure glucose.

GI and Health benefit

• A low glycemic index diet can help maintain weight loss
• A high glycemic index diet has been linked to increased risk of prostate, colorectal, and pancreatic cancers
• A high glycemic index diet was linked to an increased risk of breast cancer
• A high glycemic index diet appears to increase the risk of cardiovascular disease
• The lower the glycemic index of a meal, the lower the blood sugar and insulin levels after eating

WHAT SHOULD YOU DO?

If you are diabetic, pay attention.

You can’t rely on the glycemic index alone for choosing a healthy diet. Some foods, like carrot and watermelon, have a high glycemic index, but a serving contains so little carbohydrate that the effect on blood sugar is small.

The glycemic index of a particular food can also be influenced by what it is eaten with.

There are three categories of carbohydrate-containing foods:

· Low glycemic index (GI of 55 or less): Most fruits and vegetables, beans, minimally processed grains, oats, pasta, low-fat dairy foods, and nuts.

· Moderate glycemic index (GI 56 to 69): White and sweet potatoes, corn, white rice, couscous, breakfast cereals such as Cream of Wheat and Mini Wheats.

· High glycemic index (GI of 70 or higher): White bread, rice cakes, most crackers, bagels, cakes, doughnuts, croissants, waffles, most packaged breakfast cereals.

Swaps High GI to lower GI food

Instead of this high glycemic index food	Eat this lower glycemic index food
White rice	Brown rice or converted rice
Cornflakes	Bran flakes
Baked potato	Pasta
White bread	Whole-grain bread
Corn	Peas or leafy greens
Fruit roll-up	Whole fruit

MORE INFORMATION?

The complete list of the glycemic index and glycemic load for more than 1,000 foods can be found in the article "International tables of glycemic index and glycemic load values: 2008" by Fiona S. Atkinson, Kaye Foster-Powell, and Jennie C. Brand-Miller in the December 2008 issue of Diabetes Care, Vol. 31, number 12, pages 2281-2283.