This month, we have a question from a reader about sugar substitutes:
Dear Dr. Prescott,
I have been watching my carbs, especially sugar. I have blood sugar problems anyway, so I try to stay away from sugar as much as possible. I've been using Truvia in my cooking, but my mother uses a substitute called Whey-Low. It contains only a quarter of the calories of sugar and is supposed not to affect your blood sugar. I'm just wondering what's the best sugar substitute to use in terms of glycemic health?
Dr. Prescott prescribes
Sugar substitutes can serve as a useful tool to help diabetics and others manage their blood-sugar levels. But that doesn't mean that they still don't raise your blood sugar. Artificial sweeteners most commonly used to sweeten drinks such as teas, juice or diet sodas — aspartame (most commonly known by the brand names NutraSweet and Equal), saccharin (Sweet ‘n Low) and sucralose (Splenda) — contain no carbohydrates. So they have no effect on the blood sugar.
The same is true for stevia, a noncaloric sweetener derived from the leaves of Paraguayan shrubs that is marketed by Cargill as Truvia (and also by other manufacturers as PureVia and Stevia in the Raw).
Nevertheless, to create products that can be used in baked goods, candy, gum and food, manufacturers often pair calorie-free sugar substitutes with what are known as sugar alcohols. Technically, these compounds are neither sugars nor alcohols. But they can make life difficult for folks who are trying to manage their blood sugar.
Sugar alcohols contain fewer calories than regular sugar. Typically, they provide 1.5 to 3 calories per gram, while sugar provides 4 calories per gram. So they will raise your blood sugar.
One rule of thumb recommended by health experts is to count half the grams of sugar alcohol in a product as carbohydrates. This is because your body digests approximately half of the content of sugar alcohols; the remainder passes through your body undigested. You can find sugar alcohols on the ingredient list by looking for a telltale “-ol” ending — as in sorbitol and xylitol. And for products labeled “sugar free” or “no added sugar,” the FDA requires manufacturers to list the sugar alcohol count separately under nutritional information.
As for Whey-Low, I wasn't familiar with this product before your question. But my quick scan of the ingredient list shows that it contains three common sugars: fructose, lactose and sucrose. Although the product says that it has a low glycemic index, I would take this claim with a grain of salt (or, really, sugar).
Prescott, a physician and medical researcher, is president of the Oklahoma Medical Research Foundation. Cohen is a marathoner and OMRF's senior vice president and general counsel.