Fat Rats

Criminy…one more thing to worry about. While some studies have indicated that there is no difference between table sugar and high fructose corn syrup, this Princeton study is very interesting. Is it time to really get serious about this stuff?

High-Fructose Corn Syrup Prompts Considerably More Weight Gain, Researchers Find

A Princeton University research team has demonstrated that all sweeteners are not equal when it comes to weight gain: Rats with access to high-fructose corn syrup gained significantly more weight than those with access to table sugar, even when their overall caloric intake was the same.

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The first study showed that male rats given water sweetened with high-fructose corn syrup in addition to a standard diet of rat chow gained much more weight than male rats that received water sweetened with table sugar, or sucrose, in conjunction with the standard diet. The concentration of sugar in the sucrose solution was the same as is found in some commercial soft drinks, while the high-fructose corn syrup solution was half as concentrated as most sodas.

And it’s not just that they gained weight.

The second experiment — the first long-term study of the effects of high-fructose corn syrup consumption on obesity in lab animals — monitored weight gain, body fat and triglyceride levels in rats with access to high-fructose corn syrup over a period of six months. Compared to animals eating only rat chow, rats on a diet rich in high-fructose corn syrup showed characteristic signs of a dangerous condition known in humans as the metabolic syndrome, including abnormal weight gain, significant increases in circulating triglycerides and augmented fat deposition, especially visceral fat around the belly. Male rats in particular ballooned in size: Animals with access to high-fructose corn syrup gained 48 percent more weight than those eating a normal diet. In humans, this would be equivalent to a 200-pound man gaining 96 pounds.

“These rats aren’t just getting fat; they’re demonstrating characteristics of obesity, including substantial increases in abdominal fat and circulating triglycerides,” said Princeton graduate student Miriam Bocarsly. “In humans, these same characteristics are known risk factors for high blood pressure, coronary artery disease, cancer and diabetes.” In addition to Hoebel and Bocarsly, the research team included Princeton undergraduate Elyse Powell and visiting research associate Nicole Avena, who was affiliated with Rockefeller University during the study and is now on the faculty at the University of Florida. The Princeton researchers note that they do not know yet why high-fructose corn syrup fed to rats in their study generated more triglycerides, and more body fat that resulted in obesity.

A possible explanation: Metabolization and storage 

High-fructose corn syrup and sucrose are both compounds that contain the simple sugars fructose and glucose, but there at least two clear differences between them. First, sucrose is composed of equal amounts of the two simple sugars — it is 50 percent fructose and 50 percent glucose — but the typical high-fructose corn syrup used in this study features a slightly imbalanced ratio, containing 55 percent fructose and 42 percent glucose. Larger sugar molecules called higher saccharides make up the remaining 3 percent of the sweetener. Second, as a result of the manufacturing process for high-fructose corn syrup, the fructose molecules in the sweetener are free and unbound, ready for absorption and utilization. In contrast, every fructose molecule in sucrose that comes from cane sugar or beet sugar is bound to a corresponding glucose molecule and must go through an extra metabolic step before it can be utilized.

This creates a fascinating puzzle. The rats in the Princeton study became obese by drinking high-fructose corn syrup, but not by drinking sucrose. The critical differences in appetite, metabolism and gene expression that underlie this phenomenon are yet to be discovered, but may relate to the fact that excess fructose is being metabolized to produce fat, while glucose is largely being processed for energy or stored as a carbohydrate, called glycogen, in the liver and muscles.

Well, that explains the “sugar high.” I do know one thing, though I don’t drink much of it, soda made with real sugar tastes so much better than soda made with high fructose corn syrup. 

Here’s another related study on the effects of fructose on the brain.

Fructose Metabolism By The Brain Increases Food Intake And Obesity, Review Suggests

M. Daniel Lane and co-workers at The Johns Hopkins University School of Medicine in Baltimore have now pulled together work, largely in their laboratory (many papers beginning in 2000), dealing with the role of malonyl-CoA in the signaling system in the brain (specifically the hypothalamus) that has inputs into the higher brain centers that determine feeding behavior, most notably appetite. Two papers in the journal PNAS in 2007 and 2008 showed that glucose and fructose act quite differently in the brain (hypothalamus) – glucose decreasing food intake and fructose increasing food intake. Both of these sugars signal in the brain through the malonyl-CoA signaling pathway and have inverse effects on food intake.

Got that? Consuming food or drinks with high fructose corn syrup appears to trigger appetite, while consuming foods with sucrose (sugar) in them actually satisfies the appetite. 

I used to say that McDonald’s french fries contained crack. But it appears that aside from the actual meat patties, french fries may be the least of one’s worries.   Take a peek at McDonalds menu items ingredients. (Note to vegans out there…McDonald’s fries are not vegan or even vegetarian.) And to show I’m not picking on Mickey Ds’: Burger King (pdf), Wendy’s (pdf – pg 8).

Oh heck, just go to to In-N-Out instead. They are better all the way around, from the food to how they treat their employees. Just skip the soda.

I guess it’s time to do some label reading and clear the cupboards.

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