As anyone who has ever Googled it knows, there is information all over the net on high-fructose corn syrup (HFCS). The information ranges from that put out by groups believing that HFCS is at Satan’s right hand to that put out by the Corn Refiners Association, which, as you might expect, says, Hey, HFCS is just sugar in a different form, no better or worse than plain old table sugar. Even the New York Times is entering the fray. In today’s issue Nicholas Kristof writes an opinion piece blaming HFSC for the obesity epidemic and wanting to tax it.
The HFCS promoters aren’t taking all this abuse lying down. Last week at the Experimental Biology meeting in San Francisco researchers underwritten by the HFCS industry made a presentation showing that HFCS was harmless. These findings were, of course, trumpeted to all the media by the HFCS people, and the media fell into step and reported the findings.
Before we get into what the findings were, let’s look at what we do know for sure about HFCS and fructose. First, there is no question that the consumption of fructose has increased dramatically since the development and entry of HFCS into the food supply in about 1970. Depending upon whom you want to rely, the figures as to the actual increase vary, but there is no doubt that the amount of fructose has significantly increased over the past few decades. And there is no doubt that the overall consumption of caloric sweeteners (another term for sugars) has increased over the same period. In fact, sugars of one form or another account for an unbelievable 20-25 percent of calories consumed by the average American. Think about that for a minute. Almost a quarter of our diet is composed of empty calories from a substance that we as humans were never exposed to during the 2.7 million years of our existence as humanoid creatures on this planet as we were being molded by the forces of natural selection to be the creatures we are today. (One of my favorite quotes on this comes from Blake F. Donaldson, M.D. who long ago wrote a book called Strong Medicine. Says Dr. Donaldson: “During the millions of years that our ancestors lived by hunting, every weakling who could not maintain perfect health on fresh meat and water was bred out.”)
So fact one, we know were eating more sugar in general and more fructose in particular. We also know that fructose is metabolized differently than other sugars. Glucose, for example, can be used as is by virtually every cell in the body; fructose can only be metabolized in the liver (and in sperm cells). If we eat too much glucose, the metabolic process stores it away as glycogen–if we eat too much fructose, our livers convert it to fat and, typically, store it in the liver. Why? Because glucose metabolism is tightly controlled and fructose, in simple terms, jumps the main control point in the sugar metabolism pathway. Click here to read a fairly accurate and comprehensible essay on this process. Click here for full text of a paper about fructose metabolism. (I don’t totally agree with the conclusions in this paper, but the description of the control point in fructose metabolism is accurate.)
If we forget about arguing over exactly how much the increase in fructose consumption has been over the past 30 years and focus only on what we know for sure, we can state the following with pretty much certainty: We’re eating more fructose than ever, it’s converted to fat in the liver, and fatty liver disease is on the rise. To see a previous post on non-alcoholic fatty liver disease, click here. So, the only conclusion that we can draw from these facts is that a lot of fructose is bad for us.
I’m sure the folks involved in the HFCS industry realize this and decided that they had to take some kind of steps to counter the mass of accumulating evidence indicating that fructose is not just an innocent bystander in the diabetes and obesity epidemics. What better way to do it than to underwrite a study showing that fructose is harmless, then release that fact to the press and count on them to disseminate the info under the imprimaturs of the various media outlets. That would be a way to do it.
But how could you underwrite a study and be sure of the results? Well, if you’re in the HFCS biz, you’re kind of in a no-lose situation. If you construct the study in such a way the fructose almost can’t come out looking bad, but it does despite your best efforts, then you simply don’t release the results to the press. If the results get picked up online, who cares? It’s just one more negative posting among the thousands of others out there. But if the results are positive or if they’re just not negative, then you’re armed for the attack using the media.
If I wanted to construct a study that would give non-negative results I would use young, healthy, thin subjects and I would design the study so that these subjects consumed small amounts of fructose over a short period of time because the negative effects of fructose take a while to become manifest.
Lo and behold, that’s exactly what they did. (Click here to see the study abstract.) The study subjects were 30 lean women who were randomized into two groups. Both groups ate the same number of calories for one day; one group drank soft drinks sweetened with HFCS while the other group drank their soft drinks sweetened with sucrose (table sugar). The researchers checked blood for glucose, insulin, leptin and ghrelin on this first day. The next day these subjects were allowed to eat whatever they wanted, after which blood values were once again evaluated. That was the end of the study. Would you be surprised to learn that this study showed absolutely no difference between the two groups in terms of any of these blood parameters? Nor would I.
In the first place, we don’t know how many soft drinks the subjects consumed. Since sucrose is 50 percent glucose and 50 percent fructose, one half of the sugar in the soft drinks sweetened with sucrose was actually glucose. HFCS is 55 percent fructose, so the difference in fructose between a six pack of soft drinks sweetened with HFCS and the same six pack sweetened with HFCS is about 10-14 grams. Not enough to make a difference in only one day in a lean, healthy person. So, when you get right down to it, the study didn’t show squat, but it did give the HFCS people something to issue a press release about and to talk up on their website. Notice in this report from Yahoo Health how the writer pretty much picked up the press release verbatim. That’s what the HFCS folks are counting on.
Will Rogers once said, “The only thing I know is what I read in the newspaper.”
In these days, if that’s all you know, you’re in trouble.
High-fructose corn syrup follies
Thanks. That’s really scary. High fructose corn syrup is (I believe) that worst sugar you can put into your body. I avoid it as much as possible – which on a low-carb diet isn’t all that hard. 🙂
There is still some question (in my mind at least) as to whether the increase in obesity rates is due to increased fructose consumption or whether it is due to increase sweetener consumption or a combination of the two. It is a fairly small difference (between sugar and high fructose corn syrup) in absolute percent.
However it is a more significant difference of 10% in relative terms. As to the study, there are several other problems beside the limited time frame and age of the participants. They didn’t measure triglycerides which is also considered a major effect of excess fructose consumption. Also cholesterol levels weren’t measured. Again, one would expect an increase in LDL and a decrease in HDL. Finally, by allowing subjects to eat ‘ad libitum’, (I interpret this as whatever they want) it is unclear if what they ate on the second day skewed the results, i.e. did the ‘control subjects’ satisfy their craving for a sweet fizzy beverage after being denied for a whole day. A food diary would have helped. A crossover design switching test subjects and controls would be better. All in all a quick and dirty study that should not have been allowed to be presented without better study design. As always, thanks for your time and attention.
I’d be interested in your comments re: elevated C-Reactive Protein associated with elevated cholestrol and a somewhat high blood pressure. About a week ago I went into the Phase I intervention and have already seen a significant drop in blood pressure, and I’m sure the cholestrol will follow. Haven’t had any more lab work done so don’t know what is happening or what to expect re: CRP. I’m 71, in otherwise good health, and am about 10-15 pounds over my target weight as calculated per Protein Power. Enjoy your books and these discussions.