Training & Nutrition - Sugar: The Bitter Truth

http://www.youtube.com/watch?v=dBnniua6-oM

Hello, this video has been going around my area with a lot of discussion. It's all about the noxious effects of fructose. Watch it if you have the time, it is long.

Thought I'd pass it on.

OUTSTANDING!

I wasn't expecting to watch the whole thing, but it was just too good to stop.

is there a 1 minute version of that video?

OUTSTANDING!

I wasn't expecting to watch the whole thing, but it was just too good to stop.

How'd you like the "coke-conspiracy" ? It makes me glad I really booted that sort of stuff a couple years ago.

How'd you like the "coke-conspiracy" ? It makes me glad I really booted that sort of stuff a couple years ago.

I got tired of sickly-sweet carbonated crap back in my 20's.
And since then I have read that the *carbonation* has bad effects, let alone all the other garbage in it.

I just barely remember the taste of the original Gatorade he mentions.
I do recall that the salt was noticeable, and a lot of people did not like it.

I'm going to watch that again.

excellent information, thx for posting!

I liked it. I often get frustrated when I go shopping with how difficult it is to find good food at the regular grocery store. The part where he was talking about the bread is totally true. I gave up on buying jelly a long time ago, and haven't bought peanut butter in a year. It's sad, pb&j is one of my all time favorite foods.

The body can't process sugar, is it worse than cigarette smoking?. Probably. Stick to honey.

The body can't process sugar, is it worse than cigarette smoking?. Probably. Stick to honey.
Honey has just about the same fructose/glucose ratio as high-fructose corn syrup with a little maltose and other sugars in addition. It's processed by the body in the same way as HFCS.

Are there any animal studies confirming the link between fructose consumption and liver disease? The link between alcoholism and cirrhosis is very clear. If consumption of fructose were really just as bad I'd expect to see an overwhelming epidemic of liver failures given how many people consume fructose to as great an extent as a typical alcoholic consumes ethanol.

Fruit must be real bad for you. Lots of fructose.

I liked it. I often get frustrated when I go shopping with how difficult it is to find good food at the regular grocery store. The part where he was talking about the bread is totally true. I gave up on buying jelly a long time ago, and haven't bought peanut butter in a year. It's sad, pb&j is one of my all time favorite foods.

You can find some jelly and peanut butter that is natural without all the extra added crap. I won't buy peanut butter that has more than 1 ingredient. Peanuts.

You'd have some trouble eating that much fructose through fruit(which also comes with fibre)

Honey has just about the same fructose/glucose ratio as high-fructose corn syrup with a little maltose and other sugars in addition. It's processed by the body in the same way as HFCS.

Are there any animal studies confirming the link between fructose consumption and liver disease? The link between alcoholism and cirrhosis is very clear. If consumption of fructose were really just as bad I'd expect to see an overwhelming epidemic of liver failures given how many people consume fructose to as great an extent as a typical alcoholic consumes ethanol.

Fructose does not produce an aldehyde like ethanol, hence no cirrhosis of the liver

Thank you for the post! One of the best video I have ever seen!!:thumb:

Fruit must be real bad for you. Lots of fructose.
as mentioned, bananas have fiber which helps limit the intake and also to digest the carbs (per the video? I think thats what he said).
20oz of coke = 65g sugar (http://caloriecount.about.com/calories-cola-i14147) = 4.6 bananas. (http://caloriecount.about.com/calories-banana-i69599)

excellent video and easy to watch, a shorter version would be useful for passing it around though.

Fructose does not produce an aldehyde like ethanol, hence no cirrhosis of the liver
I agree, but Lustig seems to blame the liver inflammation on the acetaldehyde then involving c-Jun N-terminal Kinase 1 (JNK1) [see around 55 minutes in video] which is also involved in fructose metabolism [at 1:06 of the video]. He makes a big deal about fructose acting as "a poison" in the liver.
That's the part where I'm skeptical. His graph just before that part of the video (1:05:46) is also not very convincing - he draws some nice straight lines through the scatterplot of actual data points that look almost random. I'll trust that it is a least-squares fit, but the confidence I'd have in it is very low (the correlation coeff. is 0.2).

as mentioned, bananas have fiber which helps limit the intake and also to digest the carbs (per the video? I think thats what he said).
20oz of coke = 65g sugar = 4.6 bananas.

OK, but our chimp relatives eat about 4 pounds of bananas and other fruits per day. With a typical banana weight of 120 g, that's over a dozen bananas and the chimp is getting almost the same sugar content as a 2 liter bottle of Coke. The sugar in bananas is about half fructose, so pretty similar to the Coke. I'd expect our basic metabolic processes to be essentially the same as the chimp with some differences such as lactose tolerance. So it would surprise me if the fructose consumption would be a problem in itself.

One clear difference between us and the chimps is that they aren't sitting quietly on a couch while munching on all that fructose-rich fruit. They need to get lots of exercise swinging through the trees to get the fruit. What's not clear in Lustig's presentation is whether consumption of fructose (whether in the form of sucrose, HFCS, or other sugars) is harmful in individuals who are exercising at a level where they are using all the calories they consume.

I agree, but Lustig seems to blame the liver inflammation on the acetaldehyde then involving c-Jun N-terminal Kinase 1 (JNK1) [see around 55 minutes in video] which is also involved in fructose metabolism [at 1:06 of the video]. He makes a big deal about fructose acting as "a poison" in the liver.

With ethanol consumption the cirrhosis is caused directly by the reactive oxygen from the aldehyde, the reactive oxygen will also cause inflammation via activation of jnk1(also activated by fructose). Lustig defines fructose as a poison because it fits the definitions given for a poison - that is an ingested substance that only the liver can metabolize.



That's the part where I'm skeptical. His graph just before that part of the video (1:05:46) is also not very convincing - he draws some nice straight lines through the scatterplot of actual data points that look almost random. I'll trust that it is a least-squares fit, but the confidence I'd have in it is very low (the correlation coeff. is 0.2).

I can't really comment on his data... sorry

Lustig defines fructose as a poison because it fits the definitions given for a poison - that is an ingested substance that only the liver can metabolize.

But I've only heard that as the definition of a poison from Lustig. Mosby's Med. Dictionary defines a poison as:
"any substance that impairs health or destroys life when ingested, inhaled, or absorbed by the body in relatively small amounts. ..." without any mention of exclusive liver metabolism as a requirement. Maybe that's why I haven't noticed any skull & cross bone labels on orange juice containers despite the high fructose content.

All in moderation.

God doesn't want us eating 12 bananas a day, unless your a god damn idiot or drinking a 2l bottle of coke. I can safely say anything in moderation won't kill you.

Also, lets not compare fruit to processed sugar, there worlds apart in terms of curing proven symptons, illnesses & ailments. Fruit got rid of my skin conditions, sugar gave me bad acne. Pineapple totally cured my illnesses related to poor a digestive system. Go figure. Anyone choosing processed sugar over fruit ain't gonna cycle fast for long.

I liked it. I often get frustrated when I go shopping with how difficult it is to find good food at the regular grocery store. The part where he was talking about the bread is totally true. I gave up on buying jelly a long time ago, and haven't bought peanut butter in a year. It's sad, pb&j is one of my all time favorite foods.

http://shop.onceagainnutbutter.com/category.sc?categoryId=15
http://www.bionaturae.com/spread.html

These should suffice if you can't find anything locally.

But I've only heard that as the definition of a poison from Lustig. Mosby's Med. Dictionary defines a poison as:
"any substance that impairs health or destroys life when ingested, inhaled, or absorbed by the body in relatively small amounts. ..." without any mention of exclusive liver metabolism as a requirement. Maybe that's why I haven't noticed any skull & cross bone labels on orange juice containers despite the high fructose content.

Uh, ok... i think you're reading into this too much. Excess fructose can impair health, will destroy life through chronic over ingestion, and is absorbed by the body in a small amount - the rest of which has to be metabolized by the liver like many other poisons. It doesn't have a skull and cross bones on it, but not all poisons have a skull and cross bone on them. The ethanol in your beer is one and mentioned in the presentation.

If you think it's safe to drink 1L of OJ a day and that you won't develop metabolic syndrome, that is cool. Otherwise i'm calling your bluff.

Uh, ok... i think you're reading into this too much. Excess fructose can impair health, will destroy life through chronic over ingestion, and is absorbed by the body in a small amount - the rest of which has to be metabolized by the liver like many other poisons. It doesn't have a skull and cross bones on it, but not all poisons have a skull and cross bone on them. The ethanol in your beer is one and mentioned in the presentation.
So are you supporting Lustig's definition of a poison (ingested substance that is only metabolized by the liver) or not? By Mosby's Med. Dict. definition (any substance that impairs health or destroys life when ingested, inhaled, or absorbed by the body in relatively small amounts. ...) fructose clearly doesn't qualify. Sure it can be harmful in very large amounts, as can almost anything, but it's generally considered to be healthy when consumed in moderation. But Lustig clearly labels it as a poison and implicates it as causing liver inflammation in addition to other negative health effects.

And I'm skeptical of the evidence he provides since most of what I saw in the video just confirmed that drinking lots of sweet soda isn't good for people - not a surprise given how obesity is associated with so many medical problems in our society. But there's a big jump required to get from there to Lustig's conclusion that it's specifically the fructose that's at fault as opposed to the high caloric intake coupled with a lack of corresponding physical activity. A study comparing groups with the same calorie diet and same physical activity but with one consuming lots of glucose while the other consumed that amount of fructose would seem to be an obvious way to test his hypothesis - which is why I initially asked if there were any animal studies like that. The closest he came to that was the short (6 day) study of med students. Interesting, but insufficient to show long-term health, or even obesity, effects.

thanks for the video, it was very informative.
I normally eat a bit of fruits every day (more than 100 grams of sugar, mostly from fruits).
I guess that would be 50 grams of fructose, which is equivalent to 1 can of coke/pepsi.
Ofcourse, you also get fiber, micro-nutrients etc... with the fruits.
This video contradicts with some of the diets that i've seen which advocate eating as much fruits as you can.

thanks for the video, it was very informative.
I normally eat a bit of fruits every day (more than 100 grams of sugar, mostly from fruits).
I guess that would be 50 grams of fructose, which is equivalent to 1 can of coke/pepsi.
I don't see any problem with that level of fruit consumption. But 100g of sugar is about 400 kcal and is equivalent to about 2.5 cans (12oz.) of Coke/Pepsi. The fruit and soda both have around half of their sugar content in the form of fructose with some variation depending on the type of fruit

I don't see any problem with that level of fruit consumption. But 100g of sugar is about 400 kcal and is equivalent to about 2.5 cans (12oz.) of Coke/Pepsi. The fruit and soda both have around half of their sugar content in the form of fructose with some variation depending on the type of fruit
You're absolutely correct, a coke/pepsi has 39/41 grams of sugar respectively. Half of which would be fructose.

So are you supporting Lustig's definition of a poison (ingested substance that is only metabolized by the liver) or not? By Mosby's Med. Dict. definition (any substance that impairs health or destroys life when ingested, inhaled, or absorbed by the body in relatively small amounts. ...) fructose clearly doesn't qualify. Sure it can be harmful in very large amounts, as can almost anything, but it's generally considered to be healthy when consumed in moderation. But Lustig clearly labels it as a poison and implicates it as causing liver inflammation in addition to other negative health effects.

And I'm skeptical of the evidence he provides since most of what I saw in the video just confirmed that drinking lots of sweet soda isn't good for people - not a surprise given how obesity is associated with so many medical problems in our society. But there's a big jump required to get from there to Lustig's conclusion that it's specifically the fructose that's at fault as opposed to the high caloric intake coupled with a lack of corresponding physical activity. A study comparing groups with the same calorie diet and same physical activity but with one consuming lots of glucose while the other consumed that amount of fructose would seem to be an obvious way to test his hypothesis - which is why I initially asked if there were any animal studies like that. The closest he came to that was the short (6 day) study of med students. Interesting, but insufficient to show long-term health, or even obesity, effects.

I'm glad to see that I'm not the only person who sees issues with Lustig's ideas. His comparison of fructose with ethanol toxicity is just goofy. His claims that the liver is damaged by processing fructose is even stranger when you consider that the liver is the major organ for converting glucose to glycogen.

Honey has just about the same fructose/glucose ratio as high-fructose corn syrup with a little maltose and other sugars in addition. It's processed by the body in the same way as HFCS.


+1 Honey can be thought of as abut the same as high fructose corn syrup with bee spit in it:rolleyes:;)

So are you supporting Lustig's definition of a poison (ingested substance that is only metabolized by the liver) or not? By Mosby's Med. Dict. definition (any substance that impairs health or destroys life when ingested, inhaled, or absorbed by the body in relatively small amounts. ...) fructose clearly doesn't qualify. Sure it can be harmful in very large amounts, as can almost anything, but it's generally considered to be healthy when consumed in moderation. But Lustig clearly labels it as a poison and implicates it as causing liver inflammation in addition to other negative health effects.

Look, the most importing thing to remember about poisons are the doses. Ethanol is fine in moderation, same with sucrose(glucose and fructose)...


And I'm skeptical of the evidence he provides since most of what I saw in the video just confirmed that drinking lots of sweet soda isn't good for people - not a surprise given how obesity is associated with so many medical problems in our society. But there's a big jump required to get from there to Lustig's conclusion that it's specifically the fructose that's at fault as opposed to the high caloric intake coupled with a lack of corresponding physical activity. A study comparing groups with the same calorie diet and same physical activity but with one consuming lots of glucose while the other consumed that amount of fructose would seem to be an obvious way to test his hypothesis - which is why I initially asked if there were any animal studies like that. The closest he came to that was the short (6 day) study of med students. Interesting, but insufficient to show long-term health, or even obesity, effects.

Of course it isn't only fructose's fault, it is just a molecule. Exercise will help with obesity, but by consuming 1L of OJ a day you will still be pre-disposing yourself to type 2 diabetes.

Look, the most importing thing to remember about poisons are the doses. Ethanol is fine in moderation, same with sucrose(glucose and fructose)...


Of course it isn't only fructose's fault, it is just a molecule. Exercise will help with obesity, but by consuming 1L of OJ a day you will still be pre-disposing yourself to type 2 diabetes.

As you say there are doses. And those doses vary widely. A poison like cyanide...not a poison that affects the liver by the way:rolleyes:...has very low doses. Dimethylmercury, a neurotoxin not a liver toxin, takes only a drop to be irreversibly deadly. Ethanol, not an immediate liver poison, takes around ten 22 mL drinks to kill a 180 lb person. And the immediate effect of ethanol is not on the liver but on the brain.

Fructose, on the other hand, could be ingested in almost pound quantities per day without any immediate effects. It can have chronic effects, no doubt, in those kinds of quantites but it wouldn't have an immediate effect. And it certainly doesn't meet the definition of 'poison' that prathmann provided.

As you say there are doses. And those doses vary widely. A poison like cyanide...not a poison that affects the liver by the way:rolleyes:...has very low doses. Dimethylmercury, a neurotoxin not a liver toxin, takes only a drop to be irreversibly deadly. Ethanol, not an immediate liver poison, takes around ten 22 mL drinks to kill a 180 lb person. And the immediate effect of ethanol is not on the liver but on the brain.

Fructose, on the other hand, could be ingested in almost pound quantities per day without any immediate effects. It can have chronic effects, no doubt, in those kinds of quantites but it wouldn't have an immediate effect. And it certainly doesn't meet the definition of 'poison' that prathmann provided.

I didn't think a substance taking immediate effect was a requirement for the definition of a poison.

Maybe we can just agree that chronic over-consumption of fructose is poisonous? Of course this would go against the USDA's definition which also labels chronic nicotine consumption through cigarettes as non-poisonous, again we are back to dosing issues.

I don't think all poisons must fall into the category of being exclusively metabolized by the liver, as per your example of cyanide, but certainly a large number of poisons can be grouped as such because of their toxic effect on the liver and the resulting complications after being metabolized.

Maybe we can just agree that chronic over-consumption of fructose is poisonous?
That would make the word "poison" essentially meaningless. Any food is going to have negative health effects if it's chronically over-consumed. So if we use that definition for poison then we have to eat poisons everyday in order to live.


I don't think all poisons must fall into the category of being exclusively metabolized by the liver, as per your example of cyanide, but certainly a large number of poisons can be grouped as such because of their toxic effect on the liver and the resulting complications after being metabolized.
Lustig's definition of poison isn't one that I've seen anywhere else. Seems like he made up a definition just so he could then turn around and label fructose as meeting it. As you say, there are substances that are clearly poisons that don't meet his definition, and conversely he considers fructose to be a poison while it isn't regarded as one by the general medical community. And he failed to present any real evidence that the fructose does have those toxic effects on the liver - it should be easy enough to feed a bunch of rats a glucose-rich diet as a control and another group a fructose-rich diet and monitor their liver health - but he never presents any such results or anything else that shows actual liver damage from fructose as opposed to other sugars.

I'm still skeptical because of our evolutionary history. We're close relatives to the chimps that have a fructose-rich diet and we share all of the basic biochemistry that Lustig presented with them. If fructose were such a problem compared to glucose I'd expect that there would have been evolutionary pressures to avoid foods with a high concentration of that sugar. But both the chimps and humans love to consume foods with a high fructose content. Of course our evolutionary history failed to protect us from the harmful effects of the comparitively recent situation where it takes almost no physical effort to acquire way more food than we need and to process it into a form that's much easier to overconsume.

That would make the word "poison" essentially meaningless. Any food is going to have negative health effects if it's chronically over-consumed. So if we use that definition for poison then we have to eat poisons everyday in order to live.


A bit of an over generalization, I said fructose not all foods.



Lustig's definition of poison isn't one that I've seen anywhere else. Seems like he made up a definition just so he could then turn around and label fructose as meeting it. As you say, there are substances that are clearly poisons that don't meet his definition, and conversely he considers fructose to be a poison while it isn't regarded as one by the general medical community. And he failed to present any real evidence that the fructose does have those toxic effects on the liver - it should be easy enough to feed a bunch of rats a glucose-rich diet as a control and another group a fructose-rich diet and monitor their liver health - but he never presents any such results or anything else that shows actual liver damage from fructose as opposed to other sugars.


In the scenario he presents fructose can be considered a poison. I don't understand why you think it can't be considered poisonous, is it the chronic-use description?



I'm still skeptical because of our evolutionary history. We're close relatives to the chimps that have a fructose-rich diet and we share all of the basic biochemistry that Lustig presented with them. If fructose were such a problem compared to glucose I'd expect that there would have been evolutionary pressures to avoid foods with a high concentration of that sugar. But both the chimps and humans love to consume foods with a high fructose content. Of course our evolutionary history failed to protect us from the harmful effects of the comparitively recent situation where it takes almost no physical effort to acquire way more food than we need and to process it into a form that's much easier to overconsume.

Like you say, the current situation of wide-spread hfcs/sucrose consumption is unique and not one encountered in the known recent past. It doesn't seem reasonable to me to assume there is some evolutionary mechanism to deal with a hfcs diet. Yes, we and our ape friends may love to consume fructose(probably because it is so energy dense) and it past situations would have sought it out with positive results but given the situation of an unlimited supply at hand everywhere(and no fibre to slow us down) we seem addicted and unable to restrains ourselves even though we seem to be destroying and damaging our health with the amounts we consume.

[...]

I'm still skeptical because of our evolutionary history. We're close relatives to the chimps that have a fructose-rich diet and we share all of the basic biochemistry that Lustig presented with them. If fructose were such a problem compared to glucose I'd expect that there would have been evolutionary pressures to avoid foods with a high concentration of that sugar. But both the chimps and humans love to consume foods with a high fructose content. Of course our evolutionary history failed to protect us from the harmful effects of the comparitively recent situation where it takes almost no physical effort to acquire way more food than we need and to process it into a form that's much easier to overconsume.

I think what you missed in Lustig's lecture is that fructose with fibre is okay as opposed to the consumption of pure fructose (i.e. processed sugar). Towards the end of the lecture, he explains why fibre is important.

A bit of an over generalization, I said fructose not all foods.



In the scenario he presents fructose can be considered a poison. I don't understand why you think it can't be considered poisonous, is it the chronic-use description?

But you said you want to consider one particular food (fructose) to be a "poison" just because it has harmful effects when overconsumed for long periods of time. If that makes fructose a poison, then it also makes all other carbohydrates to be poisons, all proteins to be poisons, and all fats to be poisons. Sure, chronic over-eating of anything is harmful, but I don't see the point in changing the definition of poison to include substances that are fine and even beneficial to consume in normal doses and only cause problems when repeatedly taken in excessively large amounts. And my specific objection is to Lustig making up a new definition of the word poison just so he can then single out one particular nutrient and label it as a poison.


Like you say, the current situation of wide-spread hfcs/sucrose consumption is unique and not one encountered in the known recent past. It doesn't seem reasonable to me to assume there is some evolutionary mechanism to deal with a hfcs diet. Yes, we and our ape friends may love to consume fructose(probably because it is so energy dense) and it past situations would have sought it out with positive results but given the situation of an unlimited supply at hand everywhere(and no fibre to slow us down) we seem addicted and unable to restrains ourselves even though we seem to be destroying and damaging our health with the amounts we consume.
There's no doubt that there are medical problems associated with over-eating in general. Lustig is in agreement with essentially everyone else on that point. But Lustig's specific claim is that fructose in particular is the source of a wide variety of health issues and that it is far more injurious than similar amounts of other carbohydrates, including glucose. It's an interesting hypothesis, but I didn't see that his talk presented any clear evidence of harm actually caused specifically by fructose. Charts showing that people who drink lots of soda have health problems doesn't provide such evidence since that's also consistent with overconsumption of calories in general being the cause. Until he or others conduct some studies that specifically look at the health effects of a fructose-rich diet contrasted to one with the same calorie level but with glucose or other sugars instead of fructose, it will remain as one of a large number of interesting, but unsupported, hypotheses.

I think what you missed in Lustig's lecture is that fructose with fibre is okay as opposed to the consumption of pure fructose (i.e. processed sugar). Towards the end of the lecture, he explains why fibre is important.
Processed sugar (sucrose) is not pure fructose. It's half fructose and half glucose - about the same ratio as found in many fruits. HFCS is also not pure fructose, but has a little more fructose than glucose. The presence of fiber doesn't change the metabolic processes he showed for the processing of the different sugars in the liver, so if metabolism of fructose causes liver disease then eating fruit would do so as well. The fiber does have the advantages of 1) cutting down on the amounts we can easily consume (but our ape relatives still manage to eat a whole lot of it), and 2) benefiting our digestion in the intestinal tract.

I didn't think a substance taking immediate effect was a requirement for the definition of a poison.

Your definition


poison - that is an ingested substance that only the liver can metabolize.

You probably don't mean that in the sense that you presented it, but it could certainly be interpreted that way. As you said there are levels of dosages and there are levels of toxicity that are immediate or chronic. Poisons that effect the liver are more chronic...i.e. ethanol abuse...than immediate.


Maybe we can just agree that chronic over-consumption of fructose is poisonous? Of course this would go against the USDA's definition which also labels chronic nicotine consumption through cigarettes as non-poisonous, again we are back to dosing issues.

No, I would not agree that chronic over-consumption of fructose is poisonous. It can cause systemic problems over the long term...obesity and associated disease...being the result but that isn't necessarily because of a build up of toxic substances. Chronic ethanol use actually causes a build up of toxic materials that damage the organ function. You can measure the production of aldehydes that cause the damage. Fructose... or glucose or lactose or sucrose or maltose or most any other sugar...are converted to glycogen by the liver. What toxic substance would be produced by the carbohydrates that would cause damage to the liver? Glucose can be converted to glycogen by the muscles but the bulk of the glycogen is produced in the liver. Since the metabolic pathway is the same for glucose as it is for fructose why doesn't glucose do the same damage that Lustig is proposing?


I don't think all poisons must fall into the category of being exclusively metabolized by the liver, as per your example of cyanide, but certainly a large number of poisons can be grouped as such because of their toxic effect on the liver and the resulting complications after being metabolized.

Again, that was not clear in your original post. And would you group all carbohydrates in the same category as fructose? The liver does the same on all carbohydrates.

What you guys are saying sounds like this.

Substance X isn't going to kill you or severely damage your health when chronically consumed in appropriate quantities. Therefore substance x is not a poison.

What i'm saying sounds like this.

Substance X is going to kill you or damage your health when chronically over-consumed. Therefore substance X is a poison.

So i say substance X is fructose, everybody says no way is fructose a poison.

Then another guy chimes in and says, substance X is cyanide and everybody nods their heads in agreement. What is the difference? the dose, just like i keep on saying.

Substance X is going to kill you or damage your health when chronically over-consumed. Therefore substance X is a poison.

So i say substance X is fructose, everybody says no way is fructose a poison.

Then another guy chimes in and says, substance X is cyanide and everybody nods their heads in agreement. What is the difference? the dose, just like i keep on saying.
Of course it depends on the dose. That's why the Med. Dict. definition that I initially posted says that a poison is something that is harmful to health when ingested *in relatively small amounts* and why Cyccommute specified the small doses needed for some specific poisons and contrasted it to the amount of fructose that can be consumed. In contrast, you seem to be supporting Lustig's definition of poison ( substance metabolized almost entirely by the liver) which *doesn't* mention the dose.

And the problem with your statement above that "Substance X is going to kill you or damage your health when chronically over-consumed. Therefore substance X is a poison." is that one can substitute anything at all for 'X'. Therefore it makes the label of 'poison' meaningless. People have died from an overdose of water, but it makes no sense to label water as a poison.

What you guys are saying sounds like this.

Substance X isn't going to kill you or severely damage your health when chronically consumed in appropriate quantities. Therefore substance x is not a poison.

What i'm saying sounds like this.

Substance X is going to kill you or damage your health when chronically over-consumed. Therefore substance X is a poison.

So i say substance X is fructose, everybody says no way is fructose a poison.

Then another guy chimes in and says, substance X is cyanide and everybody nods their heads in agreement. What is the difference? the dose, just like i keep on saying.

A substance that is a poison is either toxic to organs immediately...like cyanide and the immediate effects of ethanol...or forms some substance that is toxic to organs through metabolism. Acealdehyde in the case of ethanol or formaldehyde in the case of methanol are examples of metabolites that are toxic.

Carbohydrates...glucose, fructose, lactose, sucrose, glactose, and any number of other sugars...are converted to glycogen. For glucose the conversion can happen in the muscles but it happens largely in the liver. Glycogen isn't a toxin by any stretch of the imagination and, if the other carbohydrates are converted to glycogen along very similar pathways within the liver, how is that fructose is to be singled out as 'the bad actor'? And can you identify the glycogen produced by fructose as separate from the glycogen produced from glucose?

Excess glycogen may be converted to fat as storage against lean times which is a natural response by the body's systems. Excess fat may not be good for the body's systems and can place a burden on the organs but where is the toxin? And is excess fat toxic to the liver? And since the glycogen is made up of all the carbohydrates that the body metabolizes via a very similar pathway, which particular molecules can be identified that are from fructose?

My main objection to Lustig's hypothesis is the comparison of fructose to ethanol in terms of liver toxicity. Ethanol may eventually be converted to glycogen but the pathway is completely different. Saying that two chemicals are the same because they result, eventually, in the same product but one has to go through several different steps that involve very different products (which are toxic to the liver) makes no chemical sense. And it makes little biological sense. Use your example of a liter of orange juice consumption a day. Over 50 years you might have some problems because of excess weight. Drink a liter of ethanol per day...or just enough ethanol per day to put you in a stupor on the edge of pulmonary arrest or approximately 200 ml for a 180 lb man...and the effects on the liver will be far more immediate than 50 years or so.

Why is this? Because the intermediate metabolites of ethanol aren't the same as the intermediates of fructose. Or glucose. Or any other carbohydrate.

Additionally, if one carbohydrate is bad for you, why aren't the others? High fructose corn syrup is 55% fructose and 45% glucose. Why is glucose not considered to be bad?

I'm glad to see that I'm not the only person who sees issues with Lustig's ideas. His comparison of fructose with ethanol toxicity is just goofy. His claims that the liver is damaged by processing fructose is even stranger when you consider that the liver is the major organ for converting glucose to glycogen.

The point is that glucose can be directly metabolized, whereas fructose, being a 5-carbon sugar, must be isomerized first. This process is much more lengthy than the preparation of glucose (activation for the TCA cycle). The side processes that occur, and the fact that all fructose must be processed by the liver, rather than being directly utilized by the other tissues, are the issues.

I'd say that he does go a little overboard with the "poison" statements, but it's to underscore his point that is does interfere with normal bodily processes, and causes issues that other sugars don't. It's taking liberties with the word "poison," but I wouldn't say it's wrong.

The point is that glucose can be directly metabolized, whereas fructose, being a 5-carbon sugar, must be isomerized first. This process is much more lengthy than the preparation of glucose (activation for the TCA cycle). The side processes that occur, and the fact that all fructose must be processed by the liver, rather than being directly utilized by the other tissues, are the issues.

I'd say that he does go a little overboard with the "poison" statements, but it's to underscore his point that is does interfere with normal bodily processes, and causes issues that other sugars don't. It's taking liberties with the word "poison," but I wouldn't say it's wrong.

Fructose is a 6 carbon sugar but it is a ketose rather than an aldose.

But other carbohydrates have to go through isomerization to get to glucose too. All of them have to go through the liver to be processed. Glucose is processed primarily by the liver. Additionally, if fructose from high fructose corn syrup is bad, then fructose from other sources should be equally as bad since fructose from corn is identical to fructose from fruit or sucrose.

Fruit, and the associated fructose, is a natural part of a primate diet. Our livers do a fine job of processing it and it's not an interference with 'normal bodily processes'...it is a normal bodily process. In a few individuals, fructose can cause problems if the individual is lacking some enzymes but that can happen with any number of other carbohydrates...including glucose. The inability to process a carbohydrate doesn't mean that the carbohydrate is a poison...as in that's what's going to kill you...it just means that other processes may happen that are bad for the system.

To use the word 'poison' is wrong because it is raising something to a level of fear that it doesn't deserve. Sure, we shouldn't consume as much HFCS as we do. We shouldn't consume as much sucrose as we do. We shouldn't do a lot of things but we do them anyway for lots of reasons. But we shouldn't run around with our hair on fire all the time in a panic over what is the latest 'poison'. This one is just another in a long line.

What you guys are saying sounds like this.

Substance X isn't going to kill you or severely damage your health when chronically consumed in appropriate quantities. Therefore substance x is not a poison.

What i'm saying sounds like this.

Substance X is going to kill you or damage your health when chronically over-consumed. Therefore substance X is a poison.

So i say substance X is fructose, everybody says no way is fructose a poison.

Then another guy chimes in and says, substance X is cyanide and everybody nods their heads in agreement. What is the difference? the dose, just like i keep on saying.

Pure 02 is toxic.

Is it poisonous?

Fructose is a 6 carbon sugar but it is a ketose rather than an aldose.


I stand corrected. Someone said that in a class once, it made sense with their explanation of something else,. and it wasn't corrected. I never really looked at it. o-chem, but not biochem.


Additionally, if fructose from high fructose corn syrup is bad, then fructose from other sources should be equally as bad since fructose from corn is identical to fructose from fruit or sucrose.

He does make this point. He doesn't want kids drinking fruit juice, for example. He makes the point, though, that fiber makes a difference in transit and absorption times, and fruits are important for the micronutrients they contain. He also states that eating sugar in any form isn't ideal and may cause issues over time (the Japanese guy having a heart attack at 90), but a glut of fructose is much worse.

Dosage is another issue. How many of us would add enough sugar to a drink that it contained 30-40g of sugar per 12 ounces? Not many, but the acidity of soda covers it.

Like I said, maybe poison is a little excessive, but much of the problem of inspiring change in food habits is the attitude of the population. If the risks aren't apparent and imminent, they won't care. In truth, they eat any number of harmful substances in their food every day, and they'd probably be better off if they didn't. People like cured meats, preserved bakery goods (interestified fats are the new trans fat), soda, and every other processed or artificial food, and it's inconvenient to change.

Since we're all going to die anyway, and maybe of heart disease, what difference does it make whether I eat all the saturated fat and HFCS I can get my hands on? Heart attack at 60 instead of 80? It's not relevant to the people who are still young enough to really help themselves, and most people are too lazy to take control of their diets.

You can't control genetics, but you can sure as hell control what you eat.

One clear difference between us and the chimps is that they aren't sitting quietly on a couch while munching on all that fructose-rich fruit. They need to get lots of exercise swinging through the trees to get the fruit.

Not to mention what the bonobos do to get that banana ...

Fructose is a 6 carbon sugar but it is a ketose rather than an aldose.


What I was thinking was 5-member ring vs. 6-member ring, now that I looked at it again.

So much stupid. you really think the sugar in a pear or a banana is going to give you diabetes?

Fruit must be real bad for you. Lots of fructose.


So much stupid. you really think the sugar in a pear or a banana is going to give you diabetes?

It's obvious you haven't seen the video or completely misunderstood it, since you made such a stupid statement.

So.... which of you guys hold MD or PhD? I tend to believe someone like him who actually works with patients and does research.

A substance doesn't need to be acting immediately to be considered a poison. There is acute (one time) and chronic (prolonged exposure) poisoning. So fructose can be considered a poison. Just because it's natural doesn't make it safe. Nature is full of deadly poisons of all kinds.

A lot of stupid comments here from folks who never listened to the whole lecture.

I watched the whole lecture.

Wasn't the whole point not that fructose was technically poisonous (although he did overemphasize it for such an arguable and unimportant matter of semantics) but that the human body can't keep the consumption of low-fiber, high-fructose based foods under control? I took issue with those rediculous trendlines on his one slide, too, but remember that the figures he started off with highlighted the overconsumption trend as the problem, and demonstrated fructose to be the cause. The parts that stuck with me most strongly were the lack of leptin stimulation and the insulin-sensitivity issue, plus the hidden salt content of the same high-fructose foods.