I just watched the mentioned video[1] the other day and made some notes, so thought I'd share them since this hit the front page.
- Fructose is metabolized similarly to ethanol. Both can only mostly be metabolized in the liver, whereas glucose can be metabolized throughout the body. Both result in a storage as fat of a significant portion of the calories, possibly in the liver, where the fat causes long-term harm. Most of glucose on the other hand is stored in the liver as glycogen, which is not harmful long-term, and is the main source when you're eating a bunch of white pasta (glucose) storing up for a big race.
- If we just ate fructose from fruits we'd eat 10-20% as much as we do today. Plus fiber is protective against many of the negative effects associated with fructose. So fruit is probably on the balance still good for you or neutral in terms of the negative effects from fructose mentioned here.
- Fructose seems to suppress the post-eating dip in ghrelin levels, where ghrelin is thought to be important in encouraging us to eat--the "hunger hormone".
- Fructose doesn't cause a spike in insulin and reduces leptin, which he views as a negative, as it goes along with not discouraging further eating.
- He gave no evidence that glucose is good or beneficial, or reasons why glucose isn't a threat to increased risk of diabetes, etc. He's just chosen his battle as against fructose, as it's more winnable than against all sugar.
That last bullet is my conclusion/wrapup of his perspective. I think his points are valid, and his recommendations are good for an overweight person (ie, your average American), but he oversimplifies things to make his case simpler and stronger. If you're really trying to stay healthy, eating a ton of glucose is not a good thing--an issue he mainly skirts to keep the focus on fructose.
Listen to the presentation - he mentions glucose specifically, and explains why he thinks it's a toxin, as opposed to glucose, which he calls the fuel of life.
He also mentions that while eating a ton of glucose may make you obese, eating fructose will push you toward metabolic syndrome, which is where most of the health problems lie.
>fiber is protective against many of the negative effects associated with fructose.
Sorry for my ignorance in the subject, but isn't fiber the non digestible part of food? I've read that it absorbs some toxins, but how it can have such a big impact?
It's probably not as simple as just the fiber in fruits protecting against fructose/glucose, but it does help. (EDIT: what I mean is, don't replace fruits with a glass of metamucil and sugar :))
Soluble fiber is just that: soluble in water. In your stomach, it absorbs water and turns into a sort of carb-trapping gel. While the carbs are still eventually digested, the gel slows down the absorption. This is good, because it helps to regulate your blood sugar (not as much of a big spike and drop).
Since blood sugar spikes == insulin response == hungry signals, this is quite useful.
Insoluble fiber is also useful, but mostly just for waste processing.
I have read that fiber helps control your blood sugar levels (by carrying the sugar away before your body can process it), but I cannot find any good references.
- Fructose is metabolized similarly to ethanol. Both can only mostly be metabolized in the liver, whereas glucose can be metabolized throughout the body. Both result in a storage as fat of a significant portion of the calories, possibly in the liver, where the fat causes long-term harm. Most of glucose on the other hand is stored in the liver as glycogen, which is not harmful long-term, and is the main source when you're eating a bunch of white pasta (glucose) storing up for a big race.
- If we just ate fructose from fruits we'd eat 10-20% as much as we do today. Plus fiber is protective against many of the negative effects associated with fructose. So fruit is probably on the balance still good for you or neutral in terms of the negative effects from fructose mentioned here.
- Fructose seems to suppress the post-eating dip in ghrelin levels, where ghrelin is thought to be important in encouraging us to eat--the "hunger hormone".
- Fructose doesn't cause a spike in insulin and reduces leptin, which he views as a negative, as it goes along with not discouraging further eating.
- He gave no evidence that glucose is good or beneficial, or reasons why glucose isn't a threat to increased risk of diabetes, etc. He's just chosen his battle as against fructose, as it's more winnable than against all sugar.
That last bullet is my conclusion/wrapup of his perspective. I think his points are valid, and his recommendations are good for an overweight person (ie, your average American), but he oversimplifies things to make his case simpler and stronger. If you're really trying to stay healthy, eating a ton of glucose is not a good thing--an issue he mainly skirts to keep the focus on fructose.
[1]http://www.youtube.com/watch?v=dBnniua6-oM