A couple of months ago I watched the talk "Sugar: The Bitter Truth" by endocrinologist Dr. Robert Lustig on YouTube. The overall tone of the talk raised a couple of red flags; it sounded a little too much like conspiracy mongering for my taste, but the claim that Dr. Lustig makes is a pretty simple one: fructose doesn't only fatten us up; it's a toxin that gets metabolized very similar to ethyl alcohol. Conclusion: high fructose corn syrup and sugar should be avoided.

Have the claims of Dr. Lustig ever been independently verified or is this a one man crusade against the evil nutrition empire?

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    I have had gout for years, and tried just about everything without success.I reduced meat to, minimum once a week, stopped alcohol altogether.I was having LOTS of fruit and vegetables and my gout was worsening. Finally I have read something about Excessive fructose increasing uric acid.I experimented reducing my fruit intake to 1 a day, and bingo within days I saw a dramatic improvementTony Phylactou
    – user4248
    Commented Jul 29, 2011 at 16:25
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    Should be avoided by whom? There are more people on earth, afaik, which get to few calories than people, who get too much. Commented Aug 14, 2011 at 4:56
  • Related: skeptics.stackexchange.com/questions/3409/… Commented May 23, 2013 at 16:54

4 Answers 4


Especialy High Fructose Corn Syrup (HFCS) is a very "out there" worry for some people it seems. And also incorrectly. The key, as always, is moderation and looking at the real world.

A good read is this Science-Based Medicine article. The best quote you can probably get out of it is the ending sentence:

And stop worrying that HFCS is poisoning you and your children.

The point is made in the intro that we are not just looking at fructose/HFCS. It starts with this supporting claim (referenced)

Despite the fact that some of the underlying mechanisms are not clear, the evidence seems pretty solid that there are real risks to high fructose consumption.

But don't stop there, because here is the kicker:

However, the question remains — is HFCS more of a health risk than other sweeteners?

There is a lot of information in the article, and I suggest you read it to completely understand the sugar problem, instead of the "quick-win" frights that are raised on typical places.

One of the things mentioned is this (emphasis mine):

HFCS allowed food manufacturers to use less sugar — and thus fewer sugar calories — in their products without compromising sweetness.

So it is probably not the healthiest - just like all sugar - in high concentration, but although there is truth in the problems with fructose, it is hardly a big problem compared to your intake. Worry about other things, like a balanced diet.

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    I don't see how the "kicker" above is relevant to the quoted video or the position of Dr. Lustig. Throughout the talk he frequently points out that--within his theory--sugar and HFCS have equivalent health risks because both sweeteners contain high quantities of the fructose sugar molecule (bound up in sucrose in the case of table sugar). Thus the question: is HFCS more of a health risk than other sweeteners? is a false question. The question that would be germane to his theory would be: "Is fructose dangerous". Furthermore, he de-emphasizes the importance of calorie-counting.
    – Adam Wuerl
    Commented Jul 19, 2011 at 1:33
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    Also, Lustig points out that although HFCS allows food manufacturers to use less sugar, they haven't actually done so. And in fact they are adding HFCS to all sorts of products (e.g., plain white bread) that never had sugar to begin with.
    – benzado
    Commented Aug 2, 2011 at 21:13
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    In other words: this answer assumes Lustig is on a crusade against HFCS, which he isn't. He's on a crusade against fructose, regardless of the source.
    – benzado
    Commented Aug 2, 2011 at 21:15
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    This is a terrible answer and clearly written by someone who only watched the first five minutes of the video. Commented May 11, 2013 at 19:59
  • Dr Lustig is a con-man and his work doesn't stand up to peer review (because he doesn't publish in journals, he promotes books) but when you say "The key, as always, is moderation and looking at the real world." you need to realise that moderation is a subjective concept. Moderate banana intact for you might be 2 a week, i know people who eat 40 day but could easily eat many more if they wanted to. Moderation is a nonsense concept in science (and politics!). Commented Mar 23 at 11:06

The answers in this thread seem to be addressing HFCS.

Lustig does not differentiate from HFCS and Sugar in terms of what they do (he says, many times, that they are the same)

I've seen studies that are cited in response to HFCS criticism that say it is metabolized and has effect similar to sugar and they all come down to one point:

That excessive consumption of any sugar, be it HFCS, or table sugar, is bad

Lustig actually gives a number for excessive consumption when asked: 50g/day, and on average (in the US) consumption is well above this.

So, while it is an issue of "moderation", the problem is that we aren't moderating it, and in fact average sugar consumption per person is increasing. This is possibly due to sugar consumption making moderation difficult, having, when overconsumed, metabolism-breaking and addictive properties.

http://www.ncbi.nlm.nih.gov/pubmed/17668074 (sweetness is shown to be as addictive as cocaine in rats) http://www.ncbi.nlm.nih.gov/pubmed/15763572 (sucrose shown to have similar effects to drugs of abuse in rats)

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    Excessive consumption = 50g/day for what size person?
    – oosterwal
    Commented Aug 16, 2011 at 4:59

I'm not an expert in the field, and I couldn't quickly find sufficiently reliable sources to make any sort of claim about the specifics of this video, but here's one critical analysis. I would also like to point you to Brian Dunning's analysis of the dangers of high fructose corn syrup.

I would also like to make a more general point on this type of video. If it is one expert defending a point, that should not be enough reason to accept the point. You simply don't know if he's cherry-picking the evidence, or even if the evidence actually supports his claims. If you're not an expert yourself, try to find reviews of all the evidence.

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    Both articles have been very informative. Thanks.
    – flitzwald
    Commented Mar 5, 2011 at 12:32

Glycolysis is the method by which glucose, fructose and galactose into pyruvate, acetic acid and a Hydrogen ion. The energy released via this process is used to form ATP and NADH, which the body uses to perform work.

NADH+ must be oxidized to NAD+ or the whole glycolysis reaction stops (all the NAD+ in the cell is used up)

One method to oxidize NADH+ is fermentation - the production of ethanol.

Ethanol is only produced in animals in muscles which are overworked and starved of oxygen (ie: anaerobic) - and this process CANNOT be sustained. Oxygen MUST be returned to the cell.

Otherwise, in aerobic organisms the NAD+ is produced (essentially) via the Krebs cycle.

Bacteria also utilize fermentation.

But in order for the human body to be producing ethanol in amounts large enough to damage itself, it must be starved of oxygen for prolonged periods; which is lethal regardless of potential ethanol production.

Source: Campbell & Reece, 2005 Biology 7th Edition (International Edition), Pearson Education, Inc. 1231 pages.

  • Fructose is not (in humans) generally metabolised via glycolysis (yes, hexokinase use fructose as a substrate, but most fructose is not metabolised by it). See en.wikipedia.org/wiki/Fructolysis So I am afraid the start of this is misleading. Commented Apr 3, 2017 at 14:22

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