What is High Fructose Corn Syrup and why is it bad for you?
Dr. Joanmarie Pellegrini
Tuesday, January 11, 2011
Healthy Living on WABI has in the past covered the dangers of drinking soft drinks because of the hidden sugars and extra calories. However, is it as simple as just extra calories from sugar or is the high fructose corn syrup (HFCS) used as the sweetener that is particularly harmful?
First, let me define what the different sugars are -- sucrose is our usual table sugar and comes from cane or beet sugar. This is a two-sugar molecule with one glucose and one fructose bonded together. The sugar in our body is glucose. Dextrose is the same as glucose. Fructose is the sugar found in fruit. Fructose has a low glycemic index, which means that it takes a long time for the body to break down, resulting in a slow release of sugar, rather than a sudden rush. For this reason, it is sometimes recommended for diabetics. High fructose corn syrup comes from corn and is a mix of glucose and fructose but with higher percentage of fructose. The sugars in HFCS are single and not bonded together. Regular corn syrup is all glucose.
HFCS is less expensive to make and also preserves foods and soft drinks longer than glucose can. It tastes sweeter and has properties than add to food texture. Because of this, food manufacturers prefer HFCS. It did not exist until 1996. All non-diet soft drinks are sweetened with HFCS.
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:
Journal of Clinical Investigation, Dr. Peter J. Havel, professor of nutrition at the University of California Davis and lead author of the study 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, became less sensitive to insulin (the hormone released by the pancreas that controls blood sugar), and showed signs of dyslipidemia—elevated blood levels of lipids. The fructose group also showed increased fat production in the liver, elevated LDL or bad cholesterol and larger increases in blood triglycerides. The group drinking glucose-sweetened beverages showed none of these changes.
When fructose is consumed, however, it "appears to behave more like fat with respect to the hormones involved in body weight regulation," explains Peter Havel, associate professor of nutrition at the University of California, Davis. "Fructose doesn't stimulate insulin secretion. It doesn't increase leptin production or suppress production of ghrelin. That suggests that consuming a lot of fructose, like consuming too much fat, could contribute to weight gain." Glucose helps to control appetite and fat storage.
Americans’ obesity problem started about the same time that HFCS came on to the market. It is this association that has led some nutritionists to want to study if HFCS is metabolized differently than regular sugar. Unfortunately there is not much funding for this type of research and therefore there are not that many studies. Also, there are some conflicting studies that seem to come to the opposite conclusion (that HFCS is no worse than other sugars).
So, what can I recommend given this controversy? First, it is inconclusive that HFCS is inherently bad. However, because it is present in so many foods and all non-diet sodas, it is an omnipresent source of extra calories. Therefore, you must look at food and drink labels and try to pick the brand that doesn’t have added HFCS. Chances are good that brand will also not have added sugar of any type. It is fair to say that our intake of extra calories is a problem and that the increase in HFCS consumption is not helping. You should avoid food with added sugar regardless of whether it is table sugar or HFCS.
On Tuesday, February 15, due to concerns from viewers, Dr. Pellegrini corrected some of what she said during the Tuesday, January 11 Healthy Living segment on WABI TV 5. To see the corrected information, please click here.