Tuesday, January 4, 2011

Berries and Other Fruits May Help with Blood Sugar Control

Diabetes may be the biggest threat to Americans’ collective health over the next few decades, with rates rising at an alarming pace.

According to the National Diabetes Fact Sheet, 23.6 million children and adults in the United States – 7.8% of the population – have diabetes.
Out of this estimated total, about 5.7 million people with diabetes don’t even know they have it, as their cases are undiagnosed. Worse, some 57 million people have the cluster of metabolic signs called pre-diabetes, and 1.6 million new cases of diabetes are diagnosed in adults annually.
The UN’s World Health Organization estimates that the number of cases worldwide may double by the year 2025, due to aging, unhealthy diets, obesity, and sedentary lifestyles.

The main problem is excessive intake of sugars and starches from sodas, sweets, and white-flour breads and pastries. Repeated “spikes” in blood sugar levels increase the risk of developing metabolic syndrome (pre-diabetes) and diabetes. Conversely, blunting of blood sugar spikes in response to meals is believed to reduce the risk of developing diabetes.

Legumes and other foods high in so-called “resistant’ starches possess the power to curb spikes in blood sugar, and their effects can last for many hours following a meal.

But by no means are all sweet foods undesirable from a blood-sugar standpoint. In fact, recent studies suggested that apples produce a net positive impact on blood sugar levels, as can coffee, even when it is sweetened.

Sorting foods by blood-sugar impact
The most common measure of a food’s ability to raise blood sugar levels is its Glycemic Index, or GI. But a more accurate measure is its Glycemic Load, or GL, which ranks a food based both on the GI of its particular sugars and starches, and on the amounts it contains.

Here’s how diabetes-savvy health reporter David Mendosa explains the difference between a food’s GI and GL:
“The carbohydrate in watermelon, for example, has a high GI. But there isn't a lot of it, so watermelon's glycemic load [GL] is relatively low.” (Mendosa D 2008)

And as David says, “A GL of 20 or more is high, a GL of 11 to 19 inclusive is medium, and a GL of 10 or less is low.”

Fruits may taste sweet, but most contain relatively little sugar compared with their other major constituents … mostly fiber, with small amounts of protein.

For example, wild blueberries have a low GL of just 5, while strawberries and apples have even lower GLs, ranking at 1 and 2 respectively.

By comparison, oranges’ GL ranking ranges from 3 to 6, grapes range from 7 to 9, bananas range from 11 to 16, and raisins come in at a whopping 28.

And three studies published last year suggest that the polyphenols in apples and berries may actually help blunt blood sugar rises caused by other foods in a meal.

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