Recently Corn Refiners Association (CRA) put up a commercial showing two women discussing High Fructose Corn Syrup (HFCS - as a scientist, I just love abbreviations), which "demonstrates" that high fructose corn syrup is in fact natural and healthy by making the women who objects to it look like an idiot. The commercial (see it below) then directs you to Sweet Surprise, a website created by the CRA that, surprise!, shows high fructose corn syrup is good for you.
This commercial and the attached website are bullshit. It is like the tobacco companies "proving" that cigarettes are healthy because they show a commercial saying cigarettes are healthy. It is true that HFCS is made from corn (although corn is used to make so many things these days that that really isn't saying much ... check out the movie King Corn) and is a sweetener like table sugar, there are several important differences that make eating much worse for you.
First, you should know that HFCS is not natural, that it was invented in the 1950's as a by product of corn processing and was only industrialized in the 1970's. Natural fructose, which is found in fruit, is not present in natural corn syrup, which is made up of mostly glucose, a basic sugar out of which other sugars are made. The difference between HFCS and table sugar (which is a sugar called sucrose), is that while they are made up of the same molecules, the proportion of each type of sugar in these two sweeteners is different, and HFCS contains more fructose (approximately 10% more) than table sugar. While sucrose used to be the predominant sweetener in the United States, in the last 30 years HFCS, which is cheaper than sucrose, has become the sweetener of choice.
Some studies have shown that fructose, unlike many sucrose, does not modulate production of the hormones ghrelin, leptin and insulin that we use to control our eating. Normally, after you eat, cells in your stomach and pancreas decrease production of ghrellin, a hormone which stimulates hunger. Thus, according to these studies, HFCS also avoids your bodies natural means of telling us we are full. However, this finding is controversial as there are other studies which suggest that, in the short term HFCS does not interact with these hormones any differently than does sucrose.
So the dysregulation of our eating hormones is controversial and while HFCS does contain more fructose (and fructose does have a higher calorie count and therefore the same amount of HFCS in something contributes 10% more sugar, which equals more calories), these are not the problems with HFCS. The problem is that HFCS is used in everything, from soda to crackers to meat, because it is so cheap ... AND, more importantly because we love the taste of it. Fructose is much higher on the sweetness scale than sucrose or glucose, and that additional sweetness makes us want to eat more of the products that contain it. However, because all these products have HFCS when they shouldn't, we get a lot more sugar and calories from eating them than we should.
But so what? A common argument here is that people could eat just as many calories as sugar, so why is HFCS so bad. Well, HFCS is bad because unlike glucose, which can be used by almost every cell in your body as an energy source, fructose can only be metabolized by your liver. While we have been metabolizing fructose (in fruit) forever, the amounts of fructose we now take in are much higher. As a result,
"The exposure of the liver to such large quantities of fructose leads to rapid stimulation of lipogenesis and triglyceride accumulation, which in turn contributes to reduced insulin sensitivity and hepatic insulin resistance/glucose intolerance."
Thus, eating HFCS in everything causes you to take in a lot more sugar, and because that sugar is in the form of HFCS, the sugar contains more calories and due to the liver response to too much fructose, more of it is converted to fat. While the actual biological issues involving HFCS are more controversial and complicated, there are numerous studies showing that intake of excess fructose in the form of HFCS is driving the USA's increasing incidence of obesity and type-2 diabeties.
Personally, I think it is kind of terrifying that the technologies that we have come to see as useful, time-saving and beneficial contain numerous side effects and dangers that we have not had time to understand before we use them. But thats just me, you may love your sodas and sugar-filled foods, and just like many other things, in moderation they probably aren't so terrible. But unfortuately, because of the way HFCS exists in our food, moderation is very, very difficult and just like all the other stories about technologies that seemed great but which we now see have unknown and dangerous consequences (BPA in plastic bottles, pesticides, formaldehyde pressboard, etc ...), HFCS seems to be turning out to be much more costly and dangerous than we thought.