Wednesday, October 6, 2010

Sugar: The Bitter Truth -- A Must-See Lecture by Dr. Robert Lustig

by Chris Masterjohn

I'm a late-comer to this video so many of you may have already seen it, but if you haven't, check it out!  It's long, but once you start watching it, you won't want to stop. 

In Sugar: The Bitter Truth, Dr. Robert Lustig explains how fructose, at the high doses found in table sugar and high-fructose corn syrup, is metabolized just like alcohol, causes liver toxicity, and is likely the primary contributor to today's obesity epidemic.  Of course, the fact that sugar and high-fructose corn syrup are bad for you is nothing new, but trust me, this video excellent and is definitely a must-see.

I first found this lecture after listening to Dr. Lustig's interview with Jimmy Moore on the Livin' La Vida Low-Carb Show, a great show I've been on before.  Sean Croxton also interviewed him on his Underground Wellness show, which I've also been on in the past.  Dr. Lustig goes into greater detail on these shows about his research showing that pharmacologically blocking excess insulin in survivors of brain tumors caused them to spontaneously start eating less and exercising more, studies that launched his interest in fructose, insulin resistance, and obesity. 

Sean and Jimmy have a whole boatload of other great interviews too.


Read more about the author, Chris Masterjohn, PhD, here.


  1. I always thought the body treats all sugars basically the same,

    but if substituting sucrose/glucose/lactose for fructose, you avoid damaging the liver / dyslipedemia then...

    what's the upper limit (grams) of fructose that one should stay under?

    Also if you alrady have a fatty liver, how can you reduce it? Eat lots of in/soluble fiber?

  2. Hi Dan,

    Conservative people in Dr. Lustig's camp tend to give a number around 25-40 grams/day, but it depends on the context. His recommendations are to eat as much fruit as you want and cut out all sucrose, invert sugar, and high-fructose corn syrup. In cases of correcting fructose-induced problems, spending a couple weeks on a fructose-free diet first is purported to help.

    I don't think anyone has shown valid treatments for reversing fatty liver. However, some of the things that prevent it are coconut oil, cocoa butter, and other saturated fats, methionine, choline, green tea extract, and other antioxidants. Perhaps these could be involved in reversal too.


  3. Chris,

    Do you believe the harmful effects of sugar outlined by Dr. Lustig apply in any way to raw honey? I know there is a lot of anecdotal evidence (and some scientific research) to support the claim that raw honey is vastly superior to processed sugar, but is there any new research you can point to that suggests that raw honey consumption promotes health, rather than hindering it?


  4. Mazen,

    I haven't read these studies in full yet, but this one found that HFCS is worse than sucrose, despite similar fructose content:

    This one showed that honey providing the same amount of glucose and fructose as a purified diet using glucose and fructose purchased from Sigma had effects mostly similar to the starch control, whereas the refined glucose/fructose diet increased oxidative stress and caused increases in triglycerides, characteristic of "fructose":

    This suggests that honey does not have the harmful effects of refined fructose. The first study indicates there might be something specifically harmful about HFCS, but sucrose itself is harmful. Thus, the goodness of honey is probably largely due to its minor protective constitutents and in small part due to the possibly harmful nature of chemically isolated fructose (usually produced by isomerization from glucose).

    I would not go consuming most of my calories as honey without further research, but I would consider this grounds for using honey as a sweetener in place of refined sweeteners.

    Hope that helps,

  5. Chris,

    While I am not certain if you have the time to check out the following, I'd be interested in your thoughts regarding the following posts vis-a-vis Dr. Lustig.....

    ~Pablo Acevedo

  6. Hi Pablo,

    I don't have time to read all those comments, but I did read the initial rebuttal earlier today after someone posted it on my Facebook Fan Page, and here is a copy of the comment I responded with:

    Tony, the rebuttal makes a few good points, but none of them actually contend with any of Dr. Lustig's salient points. Dr. Lustig has made quite clear that he does not consider fructose in fruit harmful and in his interview with Sean Croxton he said that he didn't know if there was an upper limit to safe fruit consumption but he suggested that it was probably *impossible* to overdose on fruit. Dr. Lustig's points are about chronic fructose consumption leading to insulin resistance, leading to physiological effects on behavior including increased food intake and decreased physical activity, and this depends on the proportion of fructose in the diet, not whether the fructose is given alone or with other insulin-stimulating constitutents, so the points about decreased physical activity or the *acute* effects of fructose on appetite are not actually relevant.

    In the interviews with Jimmy Moore and Sean Croxton, he tells more about his initial research in survivors of brain tumors showing definitively that excess insulin production, at least in those cases, led to changes in behavior including increased food intake and decreased physical activity. In any case, taking the average of liberal and conservative camps is not a reasonable way of deriving a safe upper limit of fructose intake, and since the constitutents of fruit modify the potential toxicity of fructose, it doesn't make sense to establish such a limit without establishing context. I think Lustig's conclusion to get rid of table sugar, soda, and liquid caloric drinks besides milk and eat as much fruit as you want is more reasonable at the present moment than establishing a specific quantity of safe fructose, for which there is not sufficient evidence at the moment.

    Soon, probably tomorrow, I will be posting about how HFCS is worse than sugar and how honey is just fine.


  7. Chris,

    About nine minutes into the video Dr. Lustig states that between 1960 and 2000, in response to admonishments by health authorities, the American public reduced fat intake "from 40% to 30% of caloric intake".

    To be picky that is not really what happened, for fat intake remained roughly the same during that period and the drop in fat as a percentage of calories was the result of increased carbohydrate intake. This fact ads to Dr. Lustig's argument that increased sugar intake results in increased intake of calories.

    While total fat intake remained roughly the same between 1960 and 2000, consumption of fat from animal sources dropped from about 68% to 42% of total fat intake with the balance from vegetable sources. The adverse consequences of this change requires another hour and a half lecture.

  8. Jack,

    I think Lustig's statement is fair even if he doesn't capture every nuance in his talk -- I'm currently reading a review on fructose and fatty liver that he co-authored and they say exactly what you said about these changes.

    I definitely agree the increase in vegetable fat deserves another lecture. In my Special Reports section, I have one report on PUFA that is the first of a series of two. I'm hoping to release the other one this fall. In the mail, the current Wise Traditions is carrying a more lay reader friendly article on PUFA with a fun historical tale to go with it, which should be free on the internet in a couple months. In the mean time, with respect to liver toxicity, I have a couple blogs on the subject of PUFA:

    Coconut Not Only Protects Your Liver From Alcohol -- But From a Diet Deficient in Meat and Eggs Too!

    Maternal Intake of "Saturated Fat" Causes Liver Disease -- You Know, the Unsaturated Kind of Saturated Fat

    Thanks for your comments, Jack!


  9. Chris,

    Your Wise Traditions article is already up on their site:

    In fact I've been wanting to message you because it's been up for a week now and I was wondering why you haven't make a blog post about it, great read!


  10. What constitutes refined? How is High Fructose Corn Syrup, different from Fructose?

    For example, no doubt juicing fruits (fructose) and vegetables (sucrose) will spike your blood sugar higher and faster than eating it, but would this be considered "refinement" and therefore liver toxic?

    Also, there's sugar substitutes that come from fruits (luo han guo), and or plant leaves (stevia herb) that are several order of magnitude sweeter, and therefor only a fraction is needed, but would these extracts also be considered refined?

    How do sugar alcohols (zero calories) compare to fructose, in terms of insulin reaction and in terms of fatty liver?

    Here is also a good opinion piece about insulin..

  11. Hi Justin,

    Thanks! Didn't realize it was up!


  12. Ben,

    I'll address some of these questions in a future blog post, today or tomorrow. I agree that insulin is not bad, and that insulin resistance is. The issue with fructose is that too much causes insulin resistance, at least too much refined fructose in any case, which is mostly what is studied.


  13. So if fructose is metabolized like alcohol, and a 40% cocoa butter diet protects rats from alcohol-induced liver disease, then we should all be eating more cocoa butter. Isn't it great that research supports that some of the tastiest stuff is also good for us?

    There are some interesting cocoa butter recipes on SCD sites.

  14. I don't believe consuming too much sugar as an adverse behavior is surprising or even counter-intuitive. After all, in elementary school, we learn from the food pyramid that sugars need to consumed in the least amount of servings per day. What I do find confusing, however, is the relationship between consumption of fructose increasing, while caloric intake might actually be less than or equal to what it used to be. So many of the calories that we consume are from foods that are made with fructose and HFCS, so wouldn't there technically be a correlation between fructose intake and caloric intake?

  15. Angela,

    Yes, cocoa butter is delicious and seems to be very healthy. Where do you purchase it? It seems harder to find than other oils.

    Hi Anonymous,

    Why do you think caloric intake is decreasing? And compared to when?


  16. Nice one! All i can say in this matter is that there are a lot of ways when we talk about decreasing cholesterol or calorie intake. But we should keep in mind that our health is much more important.

  17. This video captures a lot of things about my own experience with diet and health that seemed unrelated before, but make perfect sense. HFCS is evil.

  18. I would be very careful before saying you can't eat too much fruit.

    At my period of greatest overweight, I was consuming a vast amount of fruit (as part of a "healthy diet" :-( ).

    I didn't eat what I thought of as "junk food" - no McD's, no Coke or similar (but I did drink pure fruit juice sometimes).

    I think I was addicted to fruit, and could easily polish off a bunch of bananas or a whole bag of apples. It helped if I ate them with things like cheese and/or nuts - helped me to eat more that is. Grapes were also in the mix. (Our ancestors would never have had access to that level of fruit on a regular basis).

    To be fair, I had also in my life consumed a vast amount of dried fruit e.g. dates, figs, raisins, etc, and I suspect that might have been what did the most damage.

    If fructose is bad and if fruit contains fructose ... well, draw your own conclusions. I don't think the fiber (such as it is) is any protection. I suspect Doctor Lustig is covering his own back because "everybody knows that fruit is healthy..." and he is afraid that people will reject the more important message against refined sources of fructose (mostly junk foods and drinks) if he casts aspersions against fruit.

    I would be very doubtful if there were any nutrients in any fruits that we couldn't get better elsewhere, without the risks.

  19. Honey, raw or not contains fructose. Avoid it just like you would table sugar. Use glucose sweeteners like Brown Rice Syrup.


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