Sugars & Diabetes

SUGARS & DIABETES

by Madelyn Wheeler and Marcia Levine Mazur

Recently, "Diabetes Forecast" received a letter about a subject that concerns many people with diabetes: sugar. The writer wanted to know why a magazine for people with this disease would publish a recipe (March 1996, p. 34 "Coconut Pineapple Compote") that had 20 grams of sugars in one serving.

It's an excellent question and one that "Forecast" would like to answer in print, not only for the writer, but for all our readers who have similar "sugar" concerns.

Reader Is Right

First, we agree. The sugar content in the recipe is high. But that's not the whole story.

The sugars in the compote come mainly from the fructose (fruit sugar) in the pineapple, while a small percentage comes from the lactose (milk sugar) found in the milk and yogurt.

Clearly, many nutritious foods have some form of sugar or a combination of sugars in them. Fruits, in fact, are particularly high in sugar. That means that virtually any fruit we eat--if it had a food label--would list a large quantity of sugar on that label. (To be more scientific, it would list most of its carbohydrates as sugar, but more about carbohydrates later.)

If "Forecast" could not print recipes that contained a large quantity of sugars--such as the 20 grams of sugars per serving in the Pineapple Compote--it could not print recipes that had fruit in them.

But "Forecast" does print such recipes, because sugars- -when used appropriately--are not forbidden foods for people with either type of diabetes.

What's Wrong With Sugar?

It's understandable that people with diabetes worry more about sugar than about any other food. For centuries, sugar has been considered the enemy, the worst possible thing people with diabetes could ever consume.

Why? The very name of the disease for one thing. For years diabetes mellitus was commonly referred to as "sugar diabetes." (Mellitus roughly translates as "sweet.")

That name came about because doctors once diagnosed diabetes by tasting the urine of the affected person. A sweet urine meant diabetes. (The urine of people with uncontrolled diabetes contains glucose.) Doctors then erroneously concluded that eating too much sugar had to be the cause of this disease.

In fact, one of the great pioneers of diabetes research, Dr. Frederick Allen, reported in 1920 in "The Journal of Experimental Medicine" that "sugar is a more dangerous food for human beings with any predisposition to diabetes than starch."

Dr. Allen didn't have the equipment and methods today's scientists have. And his conclusion has been disproved. But he was certainly not alone in telling people with diabetes to stay away from all sugars.

Researchers in more recent times have given the same advice. They knew that sugars such as sucrose (table sugar), fructose, lactose, and maltose (a sugar found in cereals, grains, and legumes) have simple molecular structures and have been called simple carbohydrates. (The scientific name is monosaccharides or disaccharides.)

They also knew that foods such as pasta, potatoes, bread, and crackers have complex molecular structures and have been called starches, or complex carbohydrates. (The scientific name is polysaccharides.)

They then reasoned that the body must digest and absorb foods with a simple molecular structure faster than it does foods with a complex molecular structure. They also concluded that quickly absorbed foods must raise blood glucose faster than more slowly absorbed foods.

Relying on these assumptions, they reinforced the message that sugars are harmful for people with diabetes. But few nutritionists actually experimented to see if these conclusions were true.

No Evidence

In the 1970s, several researchers were no longer satisfied with these assumptions. They began asking: How do we really know that sugars affect blood glucose levels faster than any other foods? Where is the evidence that proves sugars are especially harmful for people with diabetes?

The resulting research served to challenge long-held "truths" about the connection between diabetes and sugars. Within the American Diabetes Association, a consensus began to develop that it was time to take a closer look at the subject.

In 1993 the American Diabetes Association convened a panel of experts to review all the recently published scientific literature on nutrition and diabetes.

The panel's findings were a surprise. It uncovered no scientific evidence to support the belief that people with diabetes should eat little or no sugar of any kind.

In fact, the panel concluded that sugars, when used as part of a regular meal plan and when consumed with other foods, do not harm blood glucose control in people with either type I or type II diabetes.

Just Another Carbohydrate

The reason is that sugars are not a special kind of food. They are carbohydrates. And the body processes all carbohydrates--simple and complex--in the same way. ("Forecast"'s nutrient listings, which accompany each recipe, and Nutrition Facts on commercial food labels actually list sugars under Total Carbohydrates.)

It is the total amount of carbohydrates that you eat that affects your blood glucose levels, not where they come from.

But the sugar story is even more complex. Scientists now know that many factors besides the food itself affect blood glucose levels. For example, how has the food been processed? Cooked? What other foods are being eaten before or at the same time? How quickly is the meal consumed?

Different Sugars

Various sugars, too, have different effects on blood glucose levels, because sugars themselves have different components.

Sucrose (table sugar), for example, is actually made of glucose and fructose in equal parts. That is why nutrition labels list "sugars" rather than "sugar."

However, these differences tend to equalize when you consume sugars in combination with other foods. For this reason, dietitians recommend that you have your sugary foods as part of a total meal.

Wait A Minute

But wait. This does not mean to go ahead and have all the sugars you want. It does mean that you can have sugars as part of your diabetic diet if, like any other foods, you work them into your total daily food plan.

Also, although it's not the case with the compote recipe that prompted our reader's letter, many foods high in sugars, particularly sucrose, are also often high in calories and fat.

It's important to limit high-calorie, high-fat foods when you have diabetes. High fat diets have been linked to heart attack and stroke, and either type of diabetes is also an additional risk factor for these diseases.

Finally, sugars are not particularly healthy additions to the diet. While they add flavor and can fill a good percentage of your day's quota of carbohydrates and calories (they contain four calories per gram), sugars don't add any vitamins, minerals, or fiber.

Naturally Occurring Versus Added Sugars

Some people divide sugars into two categories: "naturally occurring" (such as the fructose in fruit) and "added" (such as the sucrose in a cookie). They think there is a significant difference between the two. There isn't.

To date, there is no scientific evidence showing that our bodies make a distinction between sugars that grew in the food, or sugars that are added by the cook or the processor.

Wait a Minute

Don't be misled. The latest findings on sugar do not give people with either type of diabetes a green light to consume all the sugars they want.

Rather, they let people with diabetes know that they can substitute sugar for other carbohydrates in their total daily food plan, and that sugary foods are best eaten with the meal.

For example, if you wanted to have a small piece of cake after a meal, you would substitute it for a food or foods that have approximately the same number of total carbohydrates. You might, for instance, have the cake instead of a bread roll or a portion of pasta. The key word is "substitute."

That's why it's important to know the number of sugar grams as well as the total number of carbohydrate grams in a food or recipe.

They All Mean Sugar

Here are some of the terms you'll see on a label that translate into "sugar."

Beet Sugar Brown Sugar Cane Sugar Carob Powder Confectioner's Sugar Corn Sweetener Corn Syrup Dextrose Fructose Galactose Glucose Granulated Sugar Honey Invert Sugar Lactose Levulose Maltose Maple Sugar Molasses Powdered Sugar Raw Sugar Sucrose Sorghum Sugar Cane Syrup Table Sugar Turbinado

Sugar Alcohols

The human body does not process (metabolize) sugar alcohols the same way it processes sugar. For that reason, The U.S. Food and Drug Administration (FDA) generally does not require them to be listed on a food label. They must be listed only if the product makes a specific sugar claim, say that it is sugar free.

However, when sugar alcohols are on the label, they are placed in a separate line under Total Carbohydrates. The following example is from a label for hard candies that contain sugar alcohol and claim they are sugar free:

Total carbohydrates 13 Dietary Fiber 0 grams Sugars 0 grams Sugar Alcohol 12 grams

Sugar alcohols have a minimal effect on blood glucose levels. But although the FDA counts sugar alcohols at two to three calories per gram (rather than the four calories per gram for other sugars), they are not problem free.

Because sugar alcohols are not completely digested in the stomach, many people find that eating too much sugar alcohol causes cramping and gas in the lower intestine.

Some sugar alcohols you'll find on labels:

Hydrogenated Starch Hydrolysate Isomalt Lactitol Mannitol Malitol Sorbitol Xylitol

Madelyn Wheeler, MS, RD, CDE, is coordinator for research dietetics at the Diabetes Research and Training Center of Indiana University Medical Center in Indianapolis. Marcia Levine Mazur is senior editor of "Diabetes Forecast."