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Author Topic:   High-Fructose Corn Syrup - the Controversy
crashfrog
Inactive Member


Message 1 of 47 (581206)
09-14-2010 1:32 PM


One of my goals as I study biochemistry is to be able to apply it to my life, and I've been left utterly mystified by the controversy about high-fructose corn syrup.

On the one hand, I've seen a number of scientific studies indicating that rats fed water sweetened with HFCS consumed more diet and apparently absorbed more calories from the same amount of diet than rats on water sweetened with sucrose. That would seem to implicate HFCS as not being "the same as sugar."

But I've also studied glycolysis in my classes, and I've been looking up human sugar digestion, and I just can't see any way that the extra 5% of fructose in HFCS could possibly make a difference. There's no mechanism to explain things like the rats study I linked to, above. HFCS enters the bloodstream as free fructose and glucose, but so does sucrose; the glycosidic linkage is broken by stomach acid and sucrase long before it enters the intestine. If the 5% difference means so much why don't we see the same suggested effects when people consume honey, which has roughly the same fructose/glucose ratio? Why don't we see the same suggested effects in the consumption of fruit, which are sweet primarily as a result of fructose - the "fruit sugar"?

Obviously the question isn't "is HFCS bad for you", the question is "is HFCS worse than sucrose"? That's the notion driving the anti-HFCS crusade and the popularity of things like "Pepsi Throwback", the sweetened-with-sucrose version of Pepsi. (I'm sure Buz will jump in to remind us how much his health improved ever since he stopped consuming refined sugars at all, and he's probably absolutely right about that.)

Personally, I can't taste the difference (though I started out thinking that for sure I could) and a summer of complete abstention from the stuff had no discernible effect on my weight, my health, my "wellness"/energy level, or anything. Without an actual mechanism I don't understand how these results can really be real.

I'm hoping the more experienced chemists can weigh in with their thoughts and a clearer notion of the metabolic effects at play, here. All I can conclude right now is that I should switch to a different soda to feed my rats.*

*I don't have any rats.


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nwr
Member
Posts: 5154
From: Geneva, Illinois
Joined: 08-08-2005


Message 2 of 47 (581211)
09-14-2010 2:08 PM
Reply to: Message 1 by crashfrog
09-14-2010 1:32 PM


I've been wondering about that. The "debate" doesn't make a lot of sense to me. It seems to be a fad. Perhaps this comes from a viral marketing campaign for some crazy diet plan.

Personally, I don't consume enough HCFS or sucrose to have an reason for concern.


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DBlevins
Member (Idle past 207 days)
Posts: 652
From: Puyallup, WA.
Joined: 02-04-2003


Message 3 of 47 (581214)
09-14-2010 3:08 PM
Reply to: Message 1 by crashfrog
09-14-2010 1:32 PM


HFCS and Metabolics
I understood that the metabolic pathways were different for the two. Fructose is metabolized fully in the liver while for glucose it is only 20%. Those fatty acids created by fructose in the liver accumulate in your liver. The reason for the fat gain seen in rats might be because the calories stored by consuming fructose is much greater (30%) versus glucose which is (<1%).

I'm quite a bit rusty on the chemistry but I'll take a look at my old organic chemistry books and see if I can find anything to clarify.

P.S. I had read an article on BBC that indicated Cancer cells use Fructose more efficiently, or something to that effect.


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purpledawn
Member
Posts: 4453
From: Indiana
Joined: 04-25-2004


Message 4 of 47 (581221)
09-14-2010 4:27 PM
Reply to: Message 1 by crashfrog
09-14-2010 1:32 PM


Too Much Sugar is Too Much Sugar
quote:
Obviously the question isn't "is HFCS bad for you", the question is "is HFCS worse than sucrose"? That's the notion driving the anti-HFCS crusade and the popularity of things like "Pepsi Throwback", the sweetened-with-sucrose version of Pepsi.
Changing out HFCS for sucrose isn't any "better" for us from what I can tell.
High Fructose Corn Syrup: Tasty Toxin or Slandered Sweetener?

I think the issue for some is that HFCS was in foods we wouldn't expect to find sugar. Foods with HFCS
Hard to moderate when it isn't just in the treats. I even found it in molasses.

The difference I found so far is where sucrose and HFCS are metabolized by the body.

Sucrose Metabolism

Fructose

Hopefully the chemists can give us a clearer difference, if any.


This message is a reply to:
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Replies to this message:
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crashfrog
Inactive Member


Message 5 of 47 (581225)
09-14-2010 4:46 PM
Reply to: Message 4 by purpledawn
09-14-2010 4:27 PM


Re: Too Much Sugar is Too Much Sugar
Agreed that too much sugar is bad.

But these links seem completely bogus:

quote:
High sucrose diets cause diabetes because of the bodys inability to metabolize large quantities of sugar. Insulin is generated in the body for sucrose metabolism, breaking the sugar down in to small parts useful for producing energy. When large quantities of sugar are consumed, the body loses the ability to pump in enough insulin to handle or manage it over a long period.

I don't think even a single part of this has sound biochemistry behind it. They make insulin sound like a catalytic enzyme, but it's actually just a hormone that signals glucose uptake by your cells. Diabetes is caused when either an autoimmune attack against your islet cells destroys their function, or your cells become so accustomed to high levels of insulin (due to sugar and starch in your diet) that they begin to become "resistant" to it, and require more insulin to trigger the same level of glucose uptake.


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Jon
Member
Posts: 4013
From: Minnesota, U.S.A.
Joined: 12-29-2005
Member Rating: 1.2


Message 6 of 47 (581227)
09-14-2010 5:21 PM
Reply to: Message 5 by crashfrog
09-14-2010 4:46 PM


Re: Too Much Sugar is Too Much Sugar
I think the health (side) effects mostly come from the fact that in recent times folk have tended to consume ungodly amounts of the trash produced by the American "food" industry in place of more balanced, natural nutritional regimens.

Jon

Edited by Jon, : No reason given.

Edited by Jon, : No reason given.

Edited by Jon, : No reason given.


"Can we say the chair on the cat, for example? Or the basket in the person? No, we can't..." - Harriet J. Ottenheimer

"Dim bulbs save on energy..." - jar


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Buzsaw
Member (Idle past 363 days)
Posts: 9158
From: new york usa
Joined: 03-14-2003


(1)
Message 7 of 47 (581229)
09-14-2010 5:29 PM
Reply to: Message 1 by crashfrog
09-14-2010 1:32 PM


Advice: None Of The Above
Crashfrog writes:

I'm hoping the more experienced chemists can weigh in with their thoughts and a clearer notion of the metabolic effects at play, here. All I can conclude right now is that I should switch to a different soda to feed my rats

How about some plain ole logic from the alternatively educated ole feller?

Use Stevia, an herbal leaf extract having 300 times the sweetening power of corn syrup and fructose. It has been used in SA for centuries. It's not dental corrosive and good for diabetics.

Alleged side effects are debatable, but likely propagated by the huge sugar industry in the US.

We use it regularly and enjoy the sweetness from it in our foods ever as much as sugar. It's the sinless sweet.

Xylitol would be 2nd choice before conventional sugars since it's suppose to be less harmful to diabetics than them.


BUZSAW B 4 U 2 C Y BUZ SAW.
The immeasurable present eternally extends the infinite past and infinitely consumes the eternal future.
This message is a reply to:
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crashfrog
Inactive Member


Message 8 of 47 (581231)
09-14-2010 5:32 PM


I'd like to just go ahead and reiterate that I'd like this to be a topic about biochemistry, human metabolic pathways, and scientific evidence for the potential harmful effects of HFCS (whatever they're supposed to be), not people's homespun dietary advice or their political notions about American agriculture.

Thanks guys, really, but I'm looking for science here, not recipes.


Replies to this message:
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Buzsaw
Member (Idle past 363 days)
Posts: 9158
From: new york usa
Joined: 03-14-2003


Message 9 of 47 (581274)
09-14-2010 9:00 PM
Reply to: Message 8 by crashfrog
09-14-2010 5:32 PM


Crashfrog writes:

Thanks guys, really, but I'm looking for science here, not recipes.

OK, but in your OP you said this. "One of my goals as I study biochemistry is to be able to apply it to my life, and I've been left utterly mystified by the controversy about high-fructose corn syrup."

I took that to mean you wanted information as to what would make your life more healthy and disease free.


BUZSAW B 4 U 2 C Y BUZ SAW.
The immeasurable present eternally extends the infinite past and infinitely consumes the eternal future.
This message is a reply to:
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crashfrog
Inactive Member


Message 10 of 47 (581280)
09-14-2010 9:39 PM
Reply to: Message 9 by Buzsaw
09-14-2010 9:00 PM


I took that to mean you wanted information as to what would make your life more healthy and disease free.

My apologies for being unclear, I guess, but my intention was to have a thread about human metabolic pathways for sugars. I'm not looking for advice; that was just the context that prompted me to open the thread.


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CosmicChimp
Member
Posts: 305
From: Muenchen Bayern Deutschland
Joined: 06-15-2007


Message 11 of 47 (581284)
09-14-2010 9:56 PM
Reply to: Message 10 by crashfrog
09-14-2010 9:39 PM


I hardly pick up any news about HFCS. Although I do know this much, I came across it in a book by Jeff Smith, in which he referred to the genetically modified corn being used to produce it, as very unhealthy. Which is ultimately a GMO issue rather than one of sugar metabolism. Politically, there is also, a powerful lobby among US cane sugar producers that keep the prices for sucrose very high (and I think subsidized too) and thereby create the demand for cheap corn syrup to replace refined sugar. Which would also be a reason for the hoopla in spite of there not being major biochemical differences.

Edited by CosmicChimp, : clarity

Edited by CosmicChimp, : No reason given.


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Taq
Member
Posts: 5218
Joined: 03-06-2009
Member Rating: 2.8


Message 12 of 47 (581294)
09-14-2010 10:54 PM
Reply to: Message 11 by CosmicChimp
09-14-2010 9:56 PM


I hardly pick up any news about HFCS. Although I do know this much, I came across it in a book by Jeff Smith, in which he referred to the genetically modified corn being used to produce it, as very unhealthy.

I would hazard a guess that he is referring to a lack of vitamins, minerals, etc. This isn't too surprising since this corn has been modified to produce lots of sugar at the expense of nutritional value. Also, none of the vitamins and minerals from the corn make it into the final product anyway.


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Taq
Member
Posts: 5218
Joined: 03-06-2009
Member Rating: 2.8


Message 13 of 47 (581298)
09-14-2010 11:07 PM
Reply to: Message 10 by crashfrog
09-14-2010 9:39 PM


From my brief reading on the interwebs it appears that fructose is metabolized differently than glucose. Glucose is directly metabolized in muscle and in mitochondria. Not so for fructose. Fructose is metabolized in the liver.

"The liver itself has a storage capacity of about 100 grams for fructose, when intake from the diet exceeds this, the liver will start to process this fructose, turning them into triglycerides and releasing them into the blood stream. This in return increases your chances for heart disease so it is definitely something you want to avoid."
http://hubpages.com/hub/Fructose_Metabolism

The same site also adds:

"Do note however that one single piece of fruit contains only about 5-8 grams of fructose so fruit consumption is not the major worry here, but rather all those other products, particularly those with HFCS that you need to be watching in the diet."

If this is true, then using HFCS is like using an equivalent amount of sucrose AND eating a piece of fruit on top of that. If you drink 2 cans of soda a day that is 40g each of sugar for a total of 80. 5% of 80 is 4 grams, so almost an additional piece of fruit according to the source above.

I can dig further, but I would strongly suspect that the liver uses fructose to run the beta-oxidation pathway in reverse and releasing the fatty acids into the blood stream.

Triglycerides (if memory serves) are metabolized by the beta-oxidation pathway, quite a different path than the glycolytic pathway. It is worth noting that skeletal muscle is heavily tilted toward the glycolytic pathway while organs such as the heart are tilted towards beta-oxidation of fatty acids. This would explain why triglycerides are higher in the HCFS rat group compared to the sucrose group.

I will add more as I read more.


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Jon
Member
Posts: 4013
From: Minnesota, U.S.A.
Joined: 12-29-2005
Member Rating: 1.2


Message 14 of 47 (581480)
09-15-2010 7:25 PM


HFCS Renaming
Of some interest, perhaps, to you Crash:

quote:
Refiners Seek to Rename High Fructose Corn Syrup...

Food companies including Tate & Lyle, Archer Daniels Midland and Cargill insist that the syrup is misunderstood and argue that, nutritionally, it is little different from ordinary sugar. But the American Medical Association has called for more research into its use.

Marion Nestle, a nutrition professor at New York University, told the New York Times that the corn refiners' move was hardly surprising: "You have to feel sorry for them. High fructose corn syrup is the new trans fat. Everyone thinks it's poison, and food companies are getting rid of it as fast as they can."


Jon


"Can we say the chair on the cat, for example? Or the basket in the person? No, we can't..." - Harriet J. Ottenheimer

"Dim bulbs save on energy..." - jar


  
onifre
Member
Posts: 4853
From: Dark Side of the Moon
Joined: 02-20-2008


Message 15 of 47 (582463)
09-21-2010 1:22 PM
Reply to: Message 1 by crashfrog
09-14-2010 1:32 PM


There's no mechanism to explain things like the rats study I linked to, above.

I ran into this by accident. Don't know if this helps, not much of a chemist - as in, I don't know shit about it. But it concludes that a HFCS diet induces leptin resistance, which is the hormone that tells your brain to stop eating and plays a key role in metabolism - from what little I read on it.

Could this be the mechanism that explains the rat study?

- Oni


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