DEAR DR. BLONZ: I continue to hear that high-fructose corn syrup is a dangerous food additive that is much worse than regular sugar. Is this true? -- J.B., Walnut Creek, California
DEAR J.B.: Let's take a look at high-fructose corn syrup (HFCS) and compare it to "regular" sugar, also known as sucrose. Both are composed of the same two simple sugars (monosaccharides): glucose and fructose. In the case of sucrose, the two simple sugars are bound together, but in HFCS, they are not.
This is an important characteristic, because fructose on its own is about 1.4 times as sweet as glucose. When bound to fructose as part of a sucrose molecule, the sweetness is less potent. Honey is also a 1:1 blend of glucose and fructose, but with honey, as with HFCS, the two are not bound; this explains why honey tastes sweeter than sucrose.
The creation of HFCS begins with cornstarch, which is not noticeably sweet. Cornstarch is made up of long chains of glucose molecules all bound together. Cornstarch gets converted to corn syrup by breaking apart the individual glucose molecules. This gets done using a starch-digesting enzyme, similar to what goes on in our body when we eat starches.
Corn syrup then gets converted to HFCS through the use of a specialized enzyme that converts glucose into fructose. Not all the glucose is typically converted, and the percentage in the final product depends on its intended use. A typical HFCS is about 55 percent fructose, 45 percent glucose. It is called a "high"-fructose corn syrup because standard corn syrup is primarily glucose.
How does HFCS compare to sucrose? A study in the July 2007 issue of the American Journal of Clinical Nutrition looked at whether HFCS might not satisfy like other sweeteners, which could then lead to excess consumption (and an increased risk of obesity), but it found no differences between HFCS and sucrose. In the same journal in May 2008, they looked at the effects of beverages sweetened with HFCS, sucrose, fructose and glucose. The study reported no differences in a number of physiological measures, including 24-hour blood glucose, insulin and triglyceride levels. Another study in the December 2013 issue of Nutrition Research reported no significant difference in the metabolic effects of HFCS versus sucrose at low, medium or high levels of consumption.
With HFCS, you get more sweetness per unit weight. It is also less expensive than cane or beet sugar, which explains why it's found in so many processed foods. Using a sweeter sweetener could translate to fewer calories for an equivalent level of sweetness.
I consider HFCS to be just another sweetener; there is no evidence that it is worse than regular sugar. The issue with any caloric sweetener relates to the level of consumption.
My bottom line is that HFCS is not a dangerous food additive -- just don't overdo it, as should be the case with any caloric sweetener. This is especially true where soft drinks are concerned.
The idea of balance may not be sexy, but its powers hold considerable sway over our life and well-being. Our biochemistry is a continuous, complex system of chemical interactions. When there is a lack of whole foods and variety, and an excess (or deficiency) of one substance, it can influence how the body reacts, and ultimately how it performs. Toss in medications, stressors or ongoing health conditions, and things become even more complicated. This is true whether we are speaking about sweeteners or any other components in our diet.
Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to firstname.lastname@example.org. Due to the volume of mail, personal replies cannot be provided.