Robert Lustigs' talk pissed me off the other day. I kept having flashbacks to him saying that fructose is basically "ethanol without the buzz." And then I read someone on this site saying, "My personal opinion is that there is no obesity without sugar. There's weight gain, but not obesity." And that made me even pissier.
I think we can all agree that drinking five Big-gulps a day is a no, no. Don't do that. You're probably going to hurt yourself. No one is saying that there isn't an upper limit on fructose. It's a dose dependent hepatoxin. Ethanol is also. But if you moderately consume ethanol, you're a-okay. The question is what is moderate sugar intake. What is too much?
Alan Aragon had a blog post a while back about Lustig's fructose alarmism. Here's the gist of it:
- Total energy consumption has gone up drastically in the last 40 years. From 2100 to 2700 cals. Why then say fructose is the major culprit?
- Lustig never gives a dosage. And while he now says that fructose in fruit is okay because it has fiber. It seems that a fiber dosage per gram of sugar is due though the whole idea of fiber making sugar less absorbable is goofy to me. Further he does not speak of the different contexts that people find themselves in (i.e. active/sedentary, fat/skinny, vitamin/mineral replete/deplete, high/low pufa etc)
- Lustig is wrong that sugar doesn't elicit satiation according to the literature.Lustig’s repeated assertion that fructose and fructose-containing sugars increase subsequent food intake seems incorrect based on a couple studies.
- The studies that are out there are extreme. The one Alan points out uses 135 grams of fructose (which would take 270 grams of sucrose for those reading quickly). This is obviously too high of a fructose dose
- There are some signs that moderate fructose intake may have a benefit much like how moderate alcohol intake has benefits.
For the specifics go here:
"There are no sacred cows" - Robb Wolf
I think it should be added that we shouldn't worship our hatred for our assumed enemies. I think that's what Lalonde's talk was about.
What says you?
Some notes from Feinmen on fructose (thanks Meredith for showing me this):
"Lustig says “ethanol is a carbohydrate.” Ethanol is not a carbohydrate. A horse is not a dog. If you said that ethanol is a carbohydrate in sophomore Organic Chemistry, you would get it wrong. Period. No partial credit."
Lustig uses the biochemistry in a misleading manner. "There is very little chemical sense in saying that ethanol and fructose are processed biologically in similar ways." "Metabolism is not static and has evolved to deal with changing conditions of diet and environment. A metabolic chart, like any map only tells you where you can go, not whether you go there." "Lustig's pathway does not show glycogen storage."
Fructose is not a toxin, is expected in the body and glucose can tautomerizes into fructose. "It is a normal metabolite. If nothing else, your body makes a certain amount of fructose. Fructose, not music (the food of love), is the preferred fuel of sperm cells. Fructose formed in the eye can be a risk but its cause is generally very high glucose. Fructose is a carbohydrate and is metabolized in ways similar to, if different in detail, from glucose but the two are interconvertible — that is why the glycemic index of fructose is 20 and not zero."
He maintains that any problem with fructose is probably a problem with glucose. I disagree.
one more day for the bounty.