The studies on fructose are on fructose... not differentiating corn based fructose from apple based fructose. Those of you claiming they're metabolized differently somehow need to come up with something showing that. Looking forward to seeing what you dig up.

The Metabolic Basis of Inherited Disease may have some more info on the difference between L-Fructose and D-Fructose in the metabolism.

http://search.barnesandnoble.com/bo...060726-5&pos=-1

Really, you can't find something on pubmed or with google scholar?

Here's something about comparing the differences between sugar (diasacchride 50% sugar 50% fructose) and HFCS (55% fructose). I guess most of you would consider sugar to be different, more natural, better somehow than fructose, right?



This is about the "GI Index" and fructose

I think we can all agree that too much sugar of any type is a problem, yes? So the question as I understand it is if HFCS is worse than fructose. And I believe the answer is yes because of the chemical differences between the two. With HFCS you have reactive compounds known as carbonyls hitting your bloodstream because of the unbound glucose and fructose molecules. I googled "reactive carbonyls HFCS" and got a whole lot of hits. Of course my goal remains to cut down on ALL sugars.

As far as the GI goes, I get a lot of my information from the Glycemic Research Institute in Washington, D.C. They've done research, and produced a few books, a few of which I have bought. Their measure of fructose and HFCS on the glycemic scale comes out significantly different. And of course they are only measuring the glycemic response, they don't speak to the reactive carbonyls.

The diseases of civilization did not appear in the 1970s with the introduction of HFCS. They have been rising steadily in the centuries since the introduction of refined sugar. I have no quibble with the claim that HFCS is somehow super-nasty, but it is not the cause of all our problems. Refined sugar and year-round imported fruit and fruit juice have been harming us for much longer.

I've been curious about these "levulose" claims before. I once asked Peter of Hyperlipid about it and he didn't think there was a difference. But a search I did just now turned up something interesting:

http://www.brewery.org/library/SugarSumm.html

So sucrose, which is abundant in fruit, contains only D-fructose. It sounds like levulose doesn't fit with dextrose. I assume this means that only the free fructose in fruits is levulose.

I tried to look up the sucrose/glucose/fructose contents of apples, oranges and grapes on the USDA site but it didn't give a breakdown. I swear it used to. Instead they have these incredibly detailed lists of fat contents. Did they change it? What's going on?

Levulose is just another name for fructose according to what I've seen. Fructose is always free. When it's bound to glucose it's called sucrose. Kind of semantics but still.

This is going to look funky but:
Amounts Per Selected Serving
%DV
Total Carbohydrate
13.8
g
5%
Dietary Fiber
2.4
g
10%
Starch
0.1
g

Sugars
10.4
g

Sucrose
2070
mg

Glucose
2430
mg

Fructose
5900
mg

Lactose
0.0
mg

Maltose
0.0
mg

Galactose
0.0
mg


From Nutritiondata.com which uses the USDA database. Last I looked USDA had that sort of info for many, but not all foods.

What is that data for?

From what I was reading, it sounds like L-fructose converts to D-fructose with extreme ease.

That's for a raw apple.

Why would you say something like that?? Surely someone must have done a study on the metabolism of corn vs. other fructose sources? You don't have any? How about anyone else?

Maybe so but I sure can't find anything. I suspect it's one of those science no-brainers, fructose is fructose despite the source of the left or right handedness of it and it all works the same.

Maybe folks are just a little too mired in the brainwashing we've received all our lives about the healthiness of sweet fruit, honey and so on? It simply never occurs to us that maybe we've been misled about certain dietary things and we still assume that "white knowledge" is true.

I suspect that fructose was probably always a kind of low dose thing in the human diet. Something the body could deal with in low quantities. But we've gone from an average consumption of under a pound to into the dozens of pounds in the last 30 years.

I did see a study that said that gluconeogenisis continued with fructose consumption wheras with glucose consumption it is suppressed.

Is that how fructose raises BG? I'm totally mystified by how it can do it at all.

The abstract was pretty confusing to read but BG did continue to increase but they said it was due to continued gluconeogenesis. Apparently it also increased blood pressure in healthy young adults. But they iv injected fructose over a 4 hr period too. So it wasn't paired with glucose like it is in table sugar and it wasn't absorbed through the stomach.

I have wild strawberries, wild raspberries, and a serviceberry tree and all those fruits are not very sweet. Over the past hundred years, breeders have made fruits sweeter. Compare an apple you can buy today with a wild apple that would have grown 100 years ago and it's way way sweeter. The fruits of today are sweeter, as is the "sweet" corn.



It's the American Paradox.

I don't think the levels of fructose most low carbers are eating is an issue, it's just that most people are sucking down soda, juice drinks, agave syrup, honey, etc, etc and they think it's healthy because it isn't sugar. Not to mention they stick it in every manufactured food under the sun.