31 July 2010

Issue: High Fructose Corn Syrup: Part 1

Today is the first part of a topic that grew in length as I was writing until I decided to split it into two parts. This is my first try investigating some issue facing people in the world, something that you may have an opinion about. Feel free to share your thoughts and observations in the comments. Come back tomorrow for part 2 which includes an experiment you can do on your own.

A Growing Problem

US Obesity and Overweight Rates
The United States is overweight. Not the land geographically, though it is quite massive, but the people who live there. The level of obesity has been climbing for the last three decades, though it has shown signs of slowing down. Two in three Americans are overweight, and the obvious place to look for answers is in our diet. One ingredient has stood out as a poster child for the growing problem. High Fructose Corn Syrup, or HFCS. I wanted to check out the claims and research, and see if I could clear up what we know about HFCS.

There are two discussions involved here. One is whether HFCS is less healthy than other sweeteners, such as sugar. The other is whether the obesity problem in the United States is tied to increased use of sweeteners in general.

The Unhealthier Sugar?

To tackle the first, it helps to compare HFCS to sugar chemically. HFCS, a thick liquid made from corn, is a mixture of fructose and glucose molecules, usually in a 55%-45% ratio with more fructose. Sugar is sucrose, found in your grocery store as crystals of table sugar. Chemically, sucrose is a fructose molecule joined to a glucose molecule. These are broken apart in the stomach and small intestine and absorbed. So sugar breaks down to nearly the same half-half mix of fructose and glucose that you get from HFCS.

Interestingly, HFCS is chemically nearly identical to honey, which has small amounts of additional sugars, but the same fructose-glucose ratio. Honey is so chemically similar to HFCS that they are often mixed to increase the amount of product to sell as pure honey (look for "raw, natural honey" or "baker's honey" to avoid HFCS). Also note that corn syrup is a completely different product than HFCS. Also called dextrose, corn syrup is another name for glucose. It is not as sweet as the others but is added to things like baked goods to get a medium level of sweetness and to improve color, as it turns brown when heated.

After sugar or HFCS are absorbed your body gets the same nutrition from each substance and processes them the same way. Studies (frustratingly few) have compared the effects of the two sweeteners on metabolism and weight gain. They generally say that, given equal amounts of sugar or HFCS, there is no significant difference in your body's reaction and weight gain, though some newer evidence is very mixed, and may adjust the conclusions on this debate(the research paper's results are much less conclusive than this article makes them out to be).

If viewing the research yourself, I warn you to be very careful about the distinction between HFCS and pure fructose, a nuance that even some research papers (and many blogs or new websites) seem to miss. Fructose is the more damaging component of sugar, and 100% fructose has been shown to be much worse than the 50-50 mix with glucose in sugar, but there is little to suggest that the extra 5% fructose in HFCS over sugar is enough to make a difference. The American Medical Association has come out to say that there is no evidence that HFCS is worse for you than equal calories of sugar.

But there is a small problem in the words above. Equal calories. One way fructose is harmful is that it causes a crash after eating large amounts, making you feel hungry sooner and eating more calories.  It is possible that this effect is stronger with HFCS than sucrose because of the extra 5% fructose, or differences in the ways the intestines absorb free fructose or fructose from sucrose.  Evidence of a significant difference is scarce, but the idea leads into the second argument, where one thing is clear.

Moderation and Exercise

US Sweetener Consumption
Americans have been eating more sweeteners, especially since the mid-eighties, when HFCS became popular. One reason may be that HFCS is about 40% cheaper than sugar, which may cause food companies to use it more frequently and in greater amounts. And while I prefer to present the evidence and let you decide what to make of it, the research and scientists converge on one conclusion. Americans' increased calorie intake, mostly from sweeteners in drinks, combined with lack of exercise, is making America fat.

But wait. I decided to muddy the waters by adding in the part about exercise. We know obesity has skyrocketed, and the two changes in lifestyle that are the most likely causes are increased calories and less exercise. Because of the complexity of factors involved, pinning it on one problem or the other is impossible. Most likely it is some combination of the two.

Further frustrating the matter is that adult physical activity data from anything other than the last twenty years seems nonexistent. Without knowing how much our activity levels have declined, it's difficult to figure out which is a bigger factor. I get the feeling that scientists think that the physical activity aspect is the real elephant.

Thankfully, the exercise trend is reversing, slightly. The CDC's recommendations on keeping a healthy weight focus on getting exercise and keeping in control of calories, especially fats and sweeteners of all kinds. Good advice. And finally, please understand that the factors in keeping a healthy weight for individual people are much more complex and varied than for the entire population. I am not saying that every overweight person just needs to cut calories and exercise, it is much more complicated than that, and a completely different discussion (Check out Healthy at any Size for a start).

Closing comment for today: There are many claims out there, but I could not find any solid research evidence that HFCS will cause other health issues than the same obesity and diabetes problems that sugar will cause. Those are important reasons to evaluate how we consume both substances.  And research should be done to check other claims. Plus, there is a mercury problem that needs to be monitored. But beyond these there is nothing with evidence for concern that I could find.

Check out part 2 here.


  1. Finally, a reasonable examination of the facts surrounding the sweeteners we eat. You were more right that you even knew when it comes to high fructose corn syrup and refined sugar being nutritionally identical. Yeah, the mercury argument is bogus. Clean drinking water has more mercury. It’s beyond insignificant. The fact that such a weak study got any media play is indicative of the fear-mongering that surrounds high fructose corn syrup.

  2. @ConsumperFreedom: Thanks for the comment and the praise. But after a little more research, I would have to strongly disagree with your statements on mercury in HFCS. The acceptable levels of mercury in drinking water is 2 ppb. One of the two studies from Jan 2009 was peer reviewed (Dufault et. al., Environmental Health), and found mercury levels in HFCS to be as high as 570 ppb, 285 times the amount acceptable in water and over 5 times the amount typically found in fish, which are constantly monitored for mercury levels.
    Now, the regulation levels in the US for mercury in fish is 1000 ppb, and 500 ppb in Canada, and the mercury in fish will be the more dangerous organic methyl-mercury, while in HFCS it will inorganic mercury, but the levels are still high enough to compare to the amount from dental fillings or certain vaccines, which are not recommended for pregnant women of small children.
    Those results are a small sample, but they are far from insignificant.

    The issue is partly that mercury was found in the levels it was, and partly because there is no reason that HFCS should contain any mercury if processed correctly. Mercury was found where there should not be any, and it is probably from an industrial source. This can be the most dangerous source of a toxin, because the concentrations can be very high due to malfunctioning equipment or processes. It is not grounds for panic, but dismissing the results as less than insignificant is very irresponsible in my mind. I think this topic is interesting enough to produce a full blog post on it, with references. I will get that up in a few days. I really do appreciate you comment and would be happy to hear more of your thoughts.