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High Fructose Corn Syrup Causes Bigger Weight Gain In Rats
krou writes "In an experiment conducted by a Princeton University team, '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.' Long-term consumption also 'led to abnormal increases in body fat, especially in the abdomen, and a rise in circulating blood fats called triglycerides.' Psychology professor Bart Hoebel commented that 'When rats are drinking high-fructose corn syrup at levels well below those in soda pop, they're becoming obese — every single one, across the board. Even when rats are fed a high-fat diet, you don't see this; they don't all gain extra weight.'"
Glad to oblige! This story was posted on Science Daily yesterday. They included the following:
Editor's Note: In response to the above-mentioned study, The Corn Refiners Association issued a statement titled "Gross Errors in Princeton Animal Study on Obesity and High Fructose Corn Syrup: Research in Humans Discredits Princeton Study" (http://www.corn.org/princeton-hfcs-study-errors.html). This link is provided for information only -- no editorial endorsement is implied.
Sorry, but that blog seems to be a wee bit on the crackpot side of things. The body does not really care how the fructose is administered - when it arrives in the intestine, it is in solution anyway, so no difference whether it comes crystalline or as HFCS. The effect should be the same. The problems that are pointed at in that post are probably true, however. Fructose triggers a lower insulin response than glucose, so the hunger persists despite caloric intake. Also, fructose is metabolized mostly, if not only, in the liver, which causes stress on the organ.
Usual table sugar - sucrose - is a disaccharide made from one molecule of fructose and one of glucose. The glucose part triggers the insulin production, which signals that you have taken in calories. So, if you use normal sugar instead of HFCS, your body knows that you got energy way faster. That seems to be the main obesity mechanism associated with HFCS.
Ubi solitudinem faciunt, pacem appellant.
Arstechnica.com covered this same study the other day. Their writeup is better than mine would be so why don't you read their article? http://arstechnica.com/science/news/2010/03/does-high-fructose-corn-syrup-make-you-fatter.ars
The abridged version of the abridged version is that this study does not conclusively prove much of anything.
It is not enough to succeed, others must fail. - Gore Vidal
Ars Technica covered this a few days ago, and their analysis (as opposed to the publicity blurb the university made up) said the study basically came out a wash. Some groups saw gains, some didn't, but there was no clear pattern.
I'm in the "HFCS should be avoided" camp at the moment, but this study doesn't really prove anything.
Comment forecast: Bits of genius surrounded by a sea of mediocrity.
Gatorade used to not use HFCS a few years ago. I noticed when they switched to using HCFS and contacted their customer relations department. Here's the response I got from Gatorade:
I am a (stressed out) med student studying for a GI physiology exam. Sugars must be broken down in the small intestine to monosaccharides to be absorbed, so sucrose becomes glucose and fructose, lactose (if you're not lactose intolerant) breaks down to glucose and galactose. Glucose and galactose are absorbed via co-transport with sodium via transport proteins. This requires a standing Na+ gradient in the cell, maintained by the Na-K pump, which requires the expenditure of energy. Fructose on the other hand enters the cell by simple facilitated diffusion through the GLUT-5 protein, meaning its transport out of the intestinal lumen requires no energy expenditure. Biochemically it it can enter the glycolytic cycle and is rapidly metabolized in much the same way as glucose.
You are right on the mechanism. However, there is another step. There is a liver-only fructokinase, which has a way higher Km than the hepatic glucokinase - so basically all fructose in the bloodstream is pulled by GLUT2 into the liver and retained there by phosphorylation through the hepatic fructokinase. The glucose also enters the liver via GLUT2, but is phosphorylated way more slowly, so a significant amount is not retained hepatically by the phosphorylation reaction. The additional liver stress and the main metabolic difference results from the fact that the subsequent metabolizing of F6P in the liver is insulin independent.
;)
Hope that suffices for starters. For more details, I'd have to break out the literature... and I am stressing my own liver with a decent red wine way too much for that at the moment
Ubi solitudinem faciunt, pacem appellant.
Sugar in general should be avoided. Fructose, which is the bad half of sugar and HFCS, is the culprit. It can only be processed by the liver, and during processing it wreaks havoc on the body's systems for controlling hunger, satiation, insulin, etc.
Take the time to watch this talk by Robert H. Lustig, MD, UCSF Professor of Pediatrics in the Division of Endocrinology. It might save your life (by extending your life).
It's not an insightful "Duh". While it's not totally new, this is one of the first long term studies comparing consumption of different forms of sugar. The study showed there's a distinct difference between consuming equal amounts of sucrose from sugarcane and fructose from corn. Even the rats that were fed twice as much sucrose didn't gain weight like the rats being fed fructose.
Make your own ketchup - it's REALLY easy, actually - just google for recipes. It's pretty much just tomato, vinegar, onion powder, and sugar (salt and oil optional), plus perhaps a little starch to get the right texture. Buy canned tomatoes in bulk, throw a can or so of them into a blender with everything else, cook and stir until smooth and even, then put it into a container in the fridge. Cleanup is just running water over everything. 15 minutes work for as much as you want to make. Incidentally, a little more sugar/oil/vinegar makes it into french dressing.
There you go - good ketchup without HFCS.
Ryan Fenton
HFCF is fructose and sucrose. Fructose is absorbed by the small intestine. Sucrose (table sugar) is broken down in the stomach and small intestine into 1 glucose molecule and 1 fructose molecule, which are then both absorbed by the small intestine. So, either way you get fructose, big deal, right? That's the conventional wisdom.
But lets look further. If you eat 1 tablespoon of HCFC 55 (equal in sweetness to 1 tablespoon sucrose), you get .55 tablespoons of fructose and .45 tablespoons of sucrose. That sucrose is turned into half fructose and half glucose before entering the bloodstream. So in reality you ate .775 tablespoons of fructose and .225 tablespoons of glucose. This is significantly more fructose than if you had eaten 1 tablespoon of sucrose. And if you're consuming sugar water (as in the study) or lots and lots of soda, you're consuming far more than a tablespoon.
Of course your claim that it's "absorbed ... in the same way that beer and alcohol is. In the liver" isn't quite correct. They're all absorbed by the small intestine, but it's true they are metabolized by the liver, albeit in completely different ways. What's might be important about the liver, though, is that it's not regulated by insulin. While glucose can be metabolized by any of the bodies cells, insulin regulates blood glucose levels. Fructose is only processed by the liver and is indifferent to insulin levels. So (in a layman's, but more detailed explanation) when you eat that 1 tablespoon of table sugar, you get half a tablespoon of unregulated sugar and half regulated. Eat the HFCF55 and most of the sugar is unregulated.
As an aside, honey is almost identical in composition to HFCF55, so if you meet any holistics bemoaning HFCF and championing honey, you can tell them to screw off.
Fructose is the culprit. But there are differences. Pure fructose is hard to absorb. Fructose in fruit is released only slowly. Both are probably OK. Fructose in sucrose needs to be split off before being absorbed, which seems to limit its rate; at normal sucrose concentrations, the fructose is also absorbed more slowly than the glucose.
HFCS is the worst of the bunch: it doesn't need to be split, and the 1:1 fructose/glucose ratio is ideal for rapid absorption, and both sugars peak simultaneously, putting a large load on the liver.
So, you're fine with moderate sucrose consumption (disaccharides) and eating fruit till you burst (fructose+fiber). Pure fructose is iffy. And HFCS is a no-no.
Parent is about 50% factually incorrect. See the earlier med student's response for the true metabolic process.
Bullshit. Go read up on the facts yourself before you start mouthing off:
http://www.medbio.info/Horn/Time%201-2/carbohydrate_metabolism.htm
Heh...
There's been a few other long-term studies that were done that were claimed "inconclusive" prior to this one. Most of them showed there was a serious problem with HFCS, but this one goes further to show that it's worse than many thought of the stuff.
If you're counting calories- it's identical. That's what the producers of HFCS would have you believe is all that matters.
The problem is that it isn't identical. Not even close.
The fructose is in an immediately available fashion to your body, which means it's absorbed on the spot, unlike sucrose which has to be cracked apart first. From there it lies in your blood stream until your liver can utilize it. Your liver absorbs and converts some of this fructose into it's roughly one day's store of glycogen. Once it has a day's worth of reserve, it starts converting the rest as it gets to it into triglycerides and fatty tissue within the liver (Look up "fatty liver disease" via Google...). While it's waiting to be converted the pancreas sees the sugar levels rise and tries to pull the sugar OUT of the blood stream by increasing insulin levels. Unfortunately, only glucose responds directly to the insulin part of your hormone system- fructose is largely processed by your liver and only your liver. This has the predictable effect of yanking the glucose out of your blood stream. At some threshold, the body detects problems caused by the sugars being ripped out of your system by that and starts producing glucagon which orders the liver to start converting the glycogen in it's store back into glucose. Over time, this swinging, the triglycerides, and the other stuff going on combine to provide leptin resistance and insulin resistance- which are the hallmark signs of Type 2 Diabetes, something we're supposedly having an "epidemic" of in the "Western" world.
And this doesn't even get into the traces of mercury and other chemicals you're exposed to when you eat HFCS as part of your diet.
In the end, while you do need Fructose, you don't need the quantities that the Western populace seem to consume, nor do you need or want it in the form that we're exposed to it.
I am not merely a "consumer" or a "taxpayer". I am a Citizen of the State of Texas