There seems to be a lot of confusion about the glycemic index of foods, and there is good reason for that. The glycemic index of a particular food is determined by the rise in blood glucose (sugar) during the two hours after its ingestion compared to the glucose response of an equivalent amount of carbohydrate in a standard food like white bread.

The glycemic index of white bread is defined as 100. Foods with a higher glycemic index than 100, like instant rice, cause a faster and higher rise in blood glucose than white bread. By comparison, the glycemic index for kidney beans is 38, which means that the blood glucose after eating this low-glycemic index food increases by only about one-third as much as after eating an equivalent amount of white bread.

In addition, the glycemic index is for single foods, but changes when food is eating with other items.

The glycemic index might seem like an important tool for people with diabetes to control their blood glucose, but the American Diabetes Association disagrees. Nutritional guidelines by ADA conclude that people with diabetes don't' have to restrict their food choices to those low on the glycemic index. Rather the ADA says the amount of carbohydrate consumed each day is more important in determining the body's glucose response than the glycemic index of each individual carbohydrate.

The glycemic index also gives a bad rap to many nutritious foods. Corn, carrots and raisins — all with significant health benefits — rank high on the glycemic index scale. The ADA recommends getting carbohydrates from whole grains, fruits, vegetables, legumes and low-fat milk.

Q and A

Q: Is it true that grapefruit could affect breast cancer risk?

A: Research has raised questions, but it is inconclusive and limited, so we do not yet have a clear answer. Natural compounds unique to grapefruit can inhibit the breakdown of certain medications, resulting in higher blood levels of those drugs. (Check with your doctor if you are taking medications.) It is possible that those compounds could act in the same way to estrogen, raising its blood levels. High blood levels of estrogen can spur the development of some breast cancers. There are three major population studies on the topic: one showing an increased risk, the other two not showing any increased risk. A 2007 population study found that postmenopausal women who ate on average a quarter grapefruit a day had higher risk of breast cancer than those who ate none. In 2008 and 2009, two other major studies found no link between the same amount of grapefruit consumption and breast cancer risk or estrogen levels. One recent intervention study has tested how grapefruit and grapefruit juice affect estrogen levels. Results were inconsistent, with differences seen between grapefruit products, specific forms of estrogen and among individual women. Grapefruit has a lot to offer nutritionally. It is a good source of vitamin C and several phytochemicals that may have health-protective effects. In laboratory studies, one called naringenin can inhibit growth of breast and several other cancer cells and inhibit early stages of colorectal cancer development. There is not enough research for a recommendation on grapefruit intake. Women who are concerned may wish to avoid or limit grapefruit and grapefruit juice until additional research provides more clarity. Otherwise, it's reasonable to enjoy grapefruit as one among a wide variety of fruits.

Information courtesy of the American Institute for Cancer Research.

Recipe

Here is a lightened up Banana-Pecan Bread from "Comfort Food Fix" by Ellie Krieger. The riper the bananas, the better the bread. Toasting the pecans allows for greater flavor from fewer nuts.

Banana-Pecan Bread

Nonstick cooking spray

1/4 cup pecan pieces

3/4 cup all-purpose flour

1 cup whole-wheat pastry flour

1/4 cup granulated sugar

1/4 cup packed light brown sugar

1 teaspoon baking soda

1/2 teaspoon baking powder

1/4 teaspoon salt

1/4 cup canola oil

1/4 cup plain nonfat yogurt

2 large eggs

1 teaspoon vanilla extract

3 very ripe, large bananas, peeled and mashed (about 1 1/2 cups)

Preheat oven to 350 degrees. Spray a 9 by 5-inch loaf pan with cooking spray. Spread the pecans on a baking sheet and toast in the oven until fragrant, about 8 minutes. Set aside to cool. In a large bowl, whisk together the flours, sugars, baking soda, baking powder and salt. In a medium bowl, whisk together the oil, yogurt, eggs and vanilla. Whisk in the bananas. Stir the wet ingredients into the dry ingredients, mixing just enough to combine them. Stir in the toasted pecans. Pour the batter into the prepared pan. Bake about 50 to 55 minutes. Allow to cool in the pan for 15 minutes, and then transfer the bread to a wire rack to cool completely before serving. Makes 8 servings, serving size, one 1-inch slice.

Per serving: 300 calories, 6 g protein, 44 g carbohydrate, 12 g fat, 55 mg cholesterol, 4 g fiber, 290 mg sodium.

Charlyn Fargo is a registered dietitian at Hy-Vee in Springfield, Ill. For comments or questions, contact her at [email protected] or follow her on Twitter @Nutrition Rd. To find out more about Charlyn Fargo and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.