Much has been written about the dangers of consuming soft drinks because of their hidden sugars and extra calories. However, is it as simple as just extra calories from sugar or is the high fructose corn syrup used as the sweetener that is particularly harmful?
It is important to understand that there are several different types of sugar.
The sugar our bodies use for energy is glucose. Dextrose is the same as glucose. Our bodies eventually break all sugars down into glucose.
Sucrose is our usual table sugar and is made from cane or beet sugar. This is a two-sugar molecule with one glucose and one fructose bonded together.
Fructose is the sugar found in fruits and vegetables. Fructose has a low glycemic index, which means that it takes a long time for the body to it break down, resulting in a slow, steady release of sugar, rather than a sudden rush. For this reason, fructose is sometimes recommended for people with diabetes.
Regular corn syrup is made from corn and is all glucose. High fructose corn syrup is a mix of glucose and fructose but with a higher percentage of fructose. The sugars in high fructose corn syrup are not bonded together.
High fructose corn syrup is less expensive to make and also preserves foods and soft drinks longer than glucose can. It did not exist until 1996. It tastes sweeter and adds to food texture. Because of this, food manufacturers prefer high fructose corn syrup to other sweeteners. All popular nondiet soft drinks are sweetened with high fructose corn syrup.
All sugars have the same caloric content but the effect on metabolism and hormones may be different. A recent study attempted to look how our bodies may differently metabolize some sugars:
In the Journal of Clinical Investigation, Dr. Peter J. Havel, professor of nutrition at the University of California at Davis, randomly assigned 32 overweight or obese men and women to drink three daily servings — 25 percent of their daily energy requirements — of a glucose- or fructose-sweetened beverage for 10 weeks. At the end of the study period, both groups had gained similar amounts of weight, but those consuming fructose-sweetened drinks showed an increase in intra-abdominal fat, the kind that embeds itself between tissues in organs. These individuals also became less sensitive to insulin, the hormone that controls blood sugar, and they had elevated levels of fat in the blood. The fructose group also showed increased fat production in the liver, elevated “bad” cholesterol and larger increases in blood triglycerides. The group drinking glucose-sweetened beverages showed none of these changes.
Americans’ obesity problem started about the same time that high fructose corn syrup came on the market. It is this association that has led some nutritionists to want to study if high fructose corn syrup is metabolized differently than regular sugar. Unfortunately there is not much funding for this type of research and therefore there are not many studies. Also, there are some studies that seem to come to the opposite conclusion, that high fructose corn syrup is no worse than other sugars.
So, what can I recommend, given this controversy? First, it is inconclusive that high fructose corn syrup is inherently unhealthful. However, because it is present in so many foods and essentially all nondiet sodas, it is an important and ever-present source of extra calories. Therefore, you must look at food and drink labels and try to pick the brands that don’t contain high fructose corn syrup.
It is fair to say that our intake of extra calories is a problem and that the increase in high fructose corn syrup consumption is not helping. You should avoid food with added sugar regardless of whether it is table sugar or high fructose corn syrup.
Correction: A previous version of this story about high fructose corn syrup needs clarification. Author Joanmarie Pellegrini, M.D., notes that high fructose corn syrup is no sweeter than table sugar and that it originally was marketed in the 1960s but did not come into widespread use until much more recently. More information is available by going to www.wabi.tv and searching under “Healthy Living.”