Why high fructose corn syrup is bad

Why high fructose corn syrup is bad

September 11, 2006, 12:03 am
Filed under: chemistry, nutrition, sugar

This post, like my post about trans fat, is more an explanation about what high fructose corn syrup is than why specifically it is bad. We toss around these terms a lot and the negative health effects of them without really understanding what we are talking about. This is my attempt to exaplain what these chemicals are in our food so that we can have a better-informed discussion about nutrition.

It all starts with glucose. It all ends with glucose too. Glucose is a hexagon of sugary sweetness. Our body uses glucose, and only glucose, for energy. Everything else has to be turned into glucose for our bodies to use it. Pretty simple, huh? But we don’t eat much plain glucose.

And then there is fructose. Fructose is a pentagon of really sugary sweetness–different shape sugar means sweeter sugar. We like fructose, and we eat a lot of it in fruits especially (that’s how I remember the name). After we eat it though, our bodies have to convert it to glucose to use it for energy.

Ah, sucrose. Now we are talking sugar. Real sugar, like our of the bag sugarin the cupboard. It is a pair of glucose and fructose, connected. It’s pretty sweet, as we can all attest to from personal experience, in between glucose and fructose. After we eat it, our bodies break up the two rings, and the glucose is ready to go. Then it converts the fructose to glucose and that is ready for energy too.

So what’s corn syrup then? It’s just a bunch of glucose. We take corn starch, which is a big long chain of glucose (not sweet at all), and break up it. Done. And cheap, cheaper than natural sucrose. But remember, glucose still isn’t as sweet at sucrose, which is what we are trying to replace usually in processed food. We need to make this glucose sweeter. Well, if our bodies can turn fructose to glucose, I bet we can figure out how to do the reverse. And we have. Corn syrup manufacturers convert a lot of the glucose into fructose, and there’s the name: high fructose corn syrup.

Now why is it bad? This is a hard question and highly controversial, like the trans fat debate. There is a lot of crap information out there on the Web too, and I don’t even want to link to Wikipedia on this topic. But look at it this way:

Complex carbohydrates are good, right? They are big long chains that take a long time to break down by our bodies, eventually turning into glucose and energy. Like anything, too much of them is bad, but we all know that these are the best of the carbs out there because they are the biggest. Bigger is better.

The next biggest carb that we care about for this issue is sucrose: good old sugar. It has two rings, remember? There are some other two-ring sugars (disacarrides) that we eat, but this is the main one. It isn’t as big as the complex carbohydrates, so it breaks down a lot faster into glucose.

Finally we have glucose and fructose, which is what is in high fructose corn syrup. These are already broken down for us. The glucose is ready to go for energy. The fructose needs to be converted to glucose first, as usual, and then it is also ready to go.

If the complex carbohydrates are the best for our bodies because they require the most breaking down, then doesn’t it follow that the worst for us are the carbohydrates that require no breaking down? It makes sense to me. If given a choice between sucrose and a fructose/glucose slurry, the sucrose is better. Of course, sucrose still isn’t that great. I am just saying that it is better than the corn syrup.

It’s the fructose part of the corn syrup, not the glucose, that causes the real issues as we are finding out. Fructose has to be converted to glucose before our bodies can use it, right? So we flood our bodies with this stuff that we can’t use for energy yet, but need to process, and our bodies are reacting in weird ways, resulting in everything from heart disease to gas (I swear, too much of anything will give you gas). But that is still be researched and debated. Our bodies are used to dealing with small to moderate amounts of fructose since we like to eat fruit (and don’t stop eating fruit because you are worried about fructose!), and so it handles it fairly well. With high fructose corn syrup in everything, we are constantly flooding ourselves with fructose in volumes that our bodies have never experienced until just 30 years ago. It’s too much!

Our bodies weren’t designed to have large quantities of fructose delivered to us on silver platters. Our bodies have enzymes to break down the long carbohydrate chains for a reason. Breaking down these carbs ahead of time confuses our system and throws it off.

Have I convinced you yet? I’ll take that as a yes. So now what? Like trans fat, you are going to find high fructose corn syrup, and sugar for that matter, in just processed foods. Avoid processed foods as much as you can. When buying processed foods, look for food that is sweetened with sugar instead of high fructose corn syrup. Better yet, look for versions of processed food that don’t have added sugar.

For example, I always make sure that I buy unsweetened apple sauce. Also, I now buy plain yogurt and mix in my own jams. My taste-buds have adapted too, and now I really don’t like the unnatural sweetness of corn syrup. I still loves sweets, but now I crave enjoy the more natural sweetness levels of fruit and even dairy.

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