Wednesday, August 10, 2005

A Challenge to the Fructose Study

The Corn Refiners Association has challenged the findings of a University of Cincinnati study that asserted the body processes fructose differently, thus leading to greater fat storage. I wrote about that study on July 29th with my blog article Fructose and Obesity.

As Food Navigator reported, [t]he Corn Refiners Association has claimed that a recent study linking fructose in soft drinks with added body fat “mischaracterizes high fructose corn syrup."


“This study unfortunately confuses pure fructose with HFCS,” she [Audrae Erickson, director of the CRA] told

“HFCS used in US caloric soft drinks is either 55 percent fructose or 42 percent - not the mixture of pure 100 percent fructose dissolved in water that was used in this study.”

This contention, that researchers and those who reported on the results of the study somehow confused the ingredient used, fructose, with high-fructose corn syrup is not only laughable, but also a clever ruse to confuse.

As evidenced by the above statement, high-fructose corn syrup does indeed contain fructose and no matter how much the CRA tries to claim that the glucose component somehow offers magical properties to the mix, it cannot deny the fact that HFCS contains fructose!

Numerous studies have shown fructose stimulates fat storage. Unlike the fructose found in fruits, where nutrients and fiber are also present, fructose sweeteners offer no nutrients, just calories. Not only that, they also are metabolized on a different pathway than sucrose or glucose, which may help explain why they stimulate fat storage - fructose, even fructose in fruit, is metabolized in the liver into triglycerides.

“The absence of glucose makes pure fructose fundamentally different from HFCS,” she said. “This is because glucose has been shown to have a tempering effect on specific metabolic effects of fructose."

What's this "tempering effect"? Ah, yes, insulin is released to handle the glucose while the fructose heads over to the liver. Personally I don't conside that a good alternative, instead I call that 'spin' to take your attention off the fact that the fructose is metabolized by the liver to churn out triglylicerides in your blood.

Let's not forget what the study found.

Researchers at the University of Cincinnati allowed mice to freely consume either water, fructose sweetened water or soft drinks. They found increased body fat in the mice that drank the fructose-sweetened water and soft drinks - despite that fact that these animals decreased the amount of calories they consumed from solid food.

This, claimed author Matthias Tschöp, MD, associate professor in UC's psychiatry department and a member of the Obesity Research Center at UC's Genome Research Institute, suggests that the total amount of calories consumed when fructose is added to diets may not be the only explanation for weight gain.

Instead, he said, consuming fructose appears to affect metabolic rate in a way that favors fat storage.

Now, while I can hear the 'calories-in -- calories-out' crowd sighing, here's a possible explanation for this metabolic puzzle...we ate fructose in our evolutionary history when it was available in the various sweet fruits and vegetables we could find during the warm season. This allowed us to pack on some fat for the inevitable lean times to come as the weather cooled and our access to fructose containing foods waned. The body fat stored from the fructose-containing foods we ate enabled us to survive those lean times. At least that's what I think.

And it's a theory held by others too. If you recall, back in June I wrote about Nature and Obesity, and how researchers at the Leeds Institute of Genetics, Health and Therapeutics (LIGHT), at the University of Leeds in the UK, are exploring the relationship between obesity in humans and our departure from our relationship with the environment, or nature. Those researchers are investigating hibernation in animals and why and how they store fat to explore how such mechanisms may work in humans who do not hibernate.

As one researcher, Professor Grant, from LIGHT said "We have fractured our relationship with our environment - we no longer respond to seasons and we don't have a fluctuating food supply. As a result we get obese and what should be a short term protective response to help us over winter becomes chronic, harmful and leads to diabetes and cardiovascular disease.”

Whether the Corn Refiners Association wants to admit it or not, we simply did not eat the volume of fructose, in any form, natural or processed, in the past as we do today. And never before in our history have we suffered the level of obesity as we do today.

While this alone is not "causation," it certainly is a correlation!

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