12 Ways Fructose Destroys Your Body

By April 25, 2014Sugar

In the early 1800s the average person ate about 1.3 teaspoons of sugar a day.  Now the average person eats somewhere between 35 and 45 teaspoons of sugar a day. But the irony is that the modern adult probably thinks they barely eat any at all.  Our food supply has been so completely and totally polluted with sugar, that it is almost impossible to buy packaged food that doesn’t contain it.

One half of that sugar tsunami is a substance called fructose. It doesn’t matter whether the sugar is made from corn (called High Fructose Corn Syrup), beets (called Beet Sugar) or cane (called Cane Sugar or often just Sugar), it is all half glucose and half fructose.  And because we have never before in our evolutionary history as a species been exposed to significant quantities of fructose, our bodies are incredibly poorly adapted to dealing with it.

Consume serious quantities (like that contained in 35-45 teaspoons of sugar a day) and the chronic diseases caused by the maladaptation start to pile up.  The picture above shows the 12 biggest disease states that science has currently linked to fructose consumption.

Join the discussion 39 Comments

  • Corn syrup (Fructose) is in way more foods than most would imagine. Some believe Monsanto is conspiring to make us all diabetic by hiding it in all sorts of prepared foods. Maybe they have a slice of the Metformin medication that most Type 2 diabetics take 2-3x daily! LoL 😉

  • Katharine says:

    Love the graphic!

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  • Hello David,

    I’m not sure whether fructose (or ethanol) is harmful in every dietary context. The main problem doesn’t seem to be the basic metabolic pathways of fructose, but primarily the Kupffer cell / TLR4 immune response.

    There’s evidence that we can prevent diet-induced obesity and insulin resistance by inhibiting this immune response (inflammation). Some papers:

    http://www.ncbi.nlm.nih.gov/pubmed/18395289 Antibiotics protect against fructose-induced hepatic lipid accumulation in mice: role of endotoxin.
    http://www.ncbi.nlm.nih.gov/pubmed/8045507 Inactivation of Kupffer cells prevents early alcohol-induced liver injury.
    http://www.ncbi.nlm.nih.gov/pubmed/17519423 Loss-of-function mutation in Toll-like receptor 4 prevents diet-induced obesity and insulin resistance.

    Recently I’ve been reading some scientific literature on glycine (the amino acid), and it seems that chronic glycine deficiency could be a major reason why we get excess inflammation from fructose, ethanol or some types of fat. In rodent studies, higher glycine intake protects powerfully from sugar- or ethanol-induced liver fat gain and insulin resistance. You ca n find the scientific references here:


    Vladimir Heiskanen

  • arf says:

    How about linking references to some research papers that give evidence to your (just kidding, I mean R.Lustig) claims? Just a funny cartoon doesn’t cut it.

  • David Gillespie says:

    Arf if you search this site you’ll find that I have written at least one article (and usually quite a few) setting out the science (with the links to the research) behind each of these claims.

  • arf says:


    Had you answered ‘google it’ you would have been less slobby than expecting everybody to read all your 30 articles about sugar to find the references to the science you think your cartoon is based on. You are just polemics, certainly no serious debater.

  • David Gillespie says:

    In spite of your appalling rudeness Arf, I will prepare a summary post of the research. It would be nice to have it all in one place.

  • arf says:


    You make wild accusations here, you make money with your claims but you can present any evidence that’s how you make a fool out of yourself. My respect is not for free, show us what you think is evidence to your claims than we can have a civilized discussion about the relevance of the science. Don’t you want to have confidence in the knowledge you base your advice on, don’t you feel a moral responsability to the people who follow your advice and who might get harmed?

  • David Gillespie says:

    Arf, given your approach so far (calling me a slobby fool for example) I am not optimistic that you have the first clue how to conduct a ‘civilised discussion’ but don’t worry you will have the opportunity to prove it shortly. As for harm, how on earth could someone be harmed by eating less sugar?

  • Arf says:

    David, this artical of yours has two critical comments, mine and the polite and educated one of Vladimir Heiskanen. You decided to engage with me only, what does this say about you? My approach worked so far, I made you walk and I’m looking forward to your references. My ideas about the benefits of sugar and fructose in particular will be part of my rebuttal to your fructophobic articles. But I will give you an idea, if sugar is just energy and having energy allows your body to function well and to regenerate itself how can having more energy be harmful and how can having less energy be beneficial? The problem is not a specific kind of fuel (sugar, starch, fat, protein) but the inability to use them correctly. Why this is, is the centre of the debate. My bet is that certain toxins are the cause and some say that poly unsaturated fatty acids a the main culprit but let’s see your science first. 😉 Cheers mate !

  • David Gillespie says:

    Arf, Vladimir’s comment is well considered and detailed. It demands (and will receive) a well considered and detailed response. Your contributions so far are nothing but unpleasant trolling, so they are easy and quick to answer.

  • Arf says:

    My request to reference the science to your claims has been easily answered, where, David ??

  • David Gillespie says:

    Thanks for your thoughtful contribution Vladimir. I am reasonably certain that one of the mechanisms of damage for over consumption of fructose (or ehtanol) is the inflammation response (via the TLR4 response to endotoxemia induced by both of these substances).

    But I don’t think its true to say there is no problem with the basic metabolic pathways of fructose. We are not well adapted to a high fructose bolus (see for example the fact that we have no PFK-1 control for fructose metabolism but do for glucose metabolism).

    That is not to say that TLR4 is not involved. I think it is. See for example http://jn.nutrition.org/content/138/8/1452.full which suggests that our innate immune response is likely to be the factor that converts mere fatty liver to cirrhosis and this http://www.hindawi.com/journals/grp/2010/212563/ which suggests it is probably what converts insulin resistance to pancreatic failure.

    But whether fructose kills us on its own or gets help from our immune system is surely beside the point?

  • Thanks for the answer, David! Hmm, interesting papers!

    Hmm, I agree that a diet with only a low amount refined sugar is usually the wise option. I prefer paleo/WAPF type of diets. However, I think that thinking about context is very important, and these glycine studies show that there probably are ways to manipulate our bodies in a way that could make sugar much less harmful.

  • […] Gillespie, D. (2014). 12 ways fructose destroys your body. Retrieved from http://davidgillespie.org/12-ways-fructose-destroys-your-body/ […]

  • […] month I threw together an infographic on the 12 Ways Fructose Destroys Your Body.  It’s a good summary, but the lawyer in my loves footnotes.  So here is the detail behind the […]

  • Louise Bean says:

    Dear David,

    Regardless of the ‘arf’s of this world, I for one, thank you for the work you are doing in getting the word out about the detriment of fructose. I don’t need to read ‘science papers’ to prove fructose’s destructive powers because I know first hand that it’s overuse has harmed me. I could be a poster for the 12 ways fructose destroys your body. Now the challenge will be to see if not eating it will reverse the trend. Please don’t give up warning the public in spite of the nay-sayers.

  • Melvyn Firmager says:

    Greetings from the Uk – Typing in the box seems to be screwing up my text, so I have continued in Word pasted here. Hope it works.

    Hi David, I have just discovered your site, whilst doing some ‘sugar’ research.

    Firstly congratulations on your polite and measured response to ‘Arf’. Hmm, if one was to change the spelling slightly and add ‘ol to his name, it might be more appropriate. But that would put me in danger of being equally gross, so I will refrain! Unfortunately Arf seems to be under the impression that it is his rudeness that has got your attention. What an unfortunate fellow.

    Anyway down to business. Arf’s assertion that energy is energy regardless, and then demanding evidence to the contrary, shows a lack of understanding.

    I leave the science to others who want such, and take us back to around 50 odd years ago with the development of the Macrobiotic movement (well actually thousands of years old) with the assertion that we should eat predominately whole grain, vegetables, pulses and a decent amount of seaweed, with other food/substances being consumed in moderation or preferably not at all.

    Whole grain, because of it’s complex carbohydrates, which break down slowly within the body, whereas, white flour, rice etc are much simpler carbos, white quickly enter the blood stream. So these along with the ‘sugars’ of fruit, refined sugar, potatoes etc should be avoided or consumed in small amounts.

    The trendy advice given today of lots of Fruit and Vegetables is wrong. Lots of vegetables yes, but fruit only in small quantities.

    I concur with Louise Bean (oh, what a lovely name), in that I too made a mistake many years ago. In my case I was drinking huge amounts of cranberry juice to help with prostate issues, not realising the huge amount of added fructose added to the product. I developed a fatty liver, and on the verge of much worse. Gave up the juice and within a couple of months my liver returned to normal.

    So Arf, do take care and come down from your ‘know all’ stance, learn and treat people with the respect they deserve. You will get so much more from life and be a happier person. I hope you will become so.

  • Melvyn Firmager says:

    Hmm, I thought there would be a response (or may be a retort) from Arf to mine. Perhaps he has taken notice and learnt something.

    But actually I have come back to see what further comments have been made about the subject, but nothing. So guess it has dried up.

  • Terence says:

    I’ve become more interested in the effects of sugar in the last couple of months because my GP told me that my glucose level was around 6.2 and I ought to be more careful with sugar consumption. Now, I don’t think I’m a high user. I don’t eat biscuits or cakes, only have juice on my morning cereals – and I’m careful with what I eat generally.

    But, the more I read, the more questions I have….

    Is my sugar problem from 3 pints of beer a week? (Unless I missed it – there’s no mention of alcohol in the book, David).

    Or, is it the fact I have 6 figs or prunes with my breakfast – or do they not count as they are fruit as opposed to juice?

    Why does the given sugar content for figs (as an example) vary so much from expert to expert.

    If we’re not supposed to have too much fruit because of the fructose content – does this viewpoint of Dr Alan Walker still stand up?

    “””” The essence of Walker’s research (Dr Alan Walker – May 15th 1979 – New York Times)is that even though humans have adopted omnivorous and carnivorous eating practices, our anatomy and physiologyhave not changed. We remain biologically a species of fruit eaters. The human digestive system has been adapted to a diet of fruits and vegetables for more than 60 million years of development.””””

    More questions than answers – but the Sugar Free Shoppers Guide seems a good place to start 🙂

  • arf says:

    David, why is it a problem, that we have no enzyme like PFK1, to control the fructose metabolism ? Isn’t fructose converted into glycogen by our liver (non fatty ones) and doesn’t appear in significant quantities in our blood and tissues? So why would a high bolus of fructose cause a problem that needs control by an enzyme if fructose is simply stored in the liver and not dumped into the bloodstream to be metabolised like glucose ? The additional 10g/40kcal of fructose, that were eaten by the NAFLD subjects (compared to the healthy control group) in the first paper, is this the excess fructose you accuse of causing ‘fatty liver’? The first paper clearly states that endotoxins from the intestine cause a chronic immune response (PIA1&TLR4), which can lead to inflamation and cirrhosis and the second paper states that saturated free fatty acids (FFA) have the same action like endotoxins. Why don’t you worry even more about fats than fructose? I agree if you eat more than 400-500g per day of fructose (or your liver is sick) your liver can’t absorb all of it and the fructose is passed on into the large intestine where it feeds bacteria who produce endotoxins (LPS) and if not evacuated quickly it is reabsorbed into the bloodstream. But that is why ‘fructophobics’ can not present any study that shows harm by fructose than studies with already sick people, excessive quantities of fructose and rodent studies, who’s liver is different than humans. As endotoxin producing bacteria feeds mainly on fiber, which they ferment to fatty acids in the large intestine, wouldn’t it be wiser to worry about excess fiber consumption?

  • […] month I threw together an infographic on the 12 Ways Fructose Destroys Your Body.  It’s a good summary, but the lawyer in my loves footnotes.  So here is the detail behind the […]

  • Roberta says:

    Thank you for the summary graphic. My husband teaches high school, and this is a convenient tool for him to introduce the topic in his classroom. (From that point, he can expand with further information, alf).

  • Alex says:

    Hi Vladimir,

    That’s all very interesting stuff. The human body obviously responds to substances in ways that are clearly only just being discovered. But I do wonder if we just didn’t eat fructose wouldn’t a lot of these problems be avoided? All this research and looking for new treatments and tests and so on, just seems on the face if it to be enabling our fructose consumption without negative consequences. Why not give up the fructose anyway?

    Alex (absolute layman and novice).

  • Colette K says:

    Hi David,

    My husband & I read your book “Sweet Poison” very informative.
    I am on my 2 and a half weeks of no sugar in my eating plan.
    I was wondering about if you have a high Cholesterol (LDL), Proactive margarine says that it will reduce your Cholesterol. I know you shouldn’t eat margarine have you any other suggestions on what to eat to reduce your Cholesterol intake besides not eating any fats or oils??? I need something for a spread on my toast with my vegemite. Thanks.

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  • Andy says:

    It’s slightly hypocritical accusing David of ‘just polemics’.
    I’m no scientist, nor do I wish to debate the science, the science and interpreted data could no doubt feed those wishing endless debate as sugar feeds those in denial.
    I’ve filled my head with information, data and test results on fats and sugars for as long as I can remember but I find a very simple logic based on thoroughly proven historical empirical evidence;

    what foods successfully nourished humans throughout evolution prior to being treated as a business for control and profit ?

    hunter, gatherer, migratory, nomadic, seasonally available, living and fresh, these are all words that easily give the simplest answers you’ll need.

    the common everyday people brainwashed by our modern commercial society and it’s capitalist sociopaths are those that need simple basic proven logic, not loads of referential scientific waffle.

    brilliant work David, keep raisin hell !

  • Kell says:

    Must be difficult dealing with trolls all day 🙂 keep it up David. I always have a critical eye on anything that looks alarmist, but I think you find a good balance between effective engaging writing and providing facts.

  • […] we do know some important things about these diseases.  We know that sugar consumption causes Type II Diabetes Fatty Liver Disease and Chronic Kidney disease and is likely to be part of […]

  • Rajpal File says:

    Hi David. I also believe you are onto it about excess hidden sugars in virtually everything. I was shocked to read the label of a can of spagetti, and to discover it hid 20 teaspoons of sugar. Unbelievable, then slowly I discovered why sugar levels are so high in anything processed, its because it sells…. ie full stop. You will never find a can of anything in my cupboard these days. No wonder there is an obesity epidemic. There would no doubt be untold benefits of limiting the allowable levels of sugar in foods. We are unknowingly poisoning ourselves and our families.
    This sell it, make money and who cares attitude makes me feel so angry. Why not encourage a campaign to boycot foods with excess sugar levels. A lack of profits is the only way to force change.
    Of course , growing your own veges is best, but that’s why sugars prevail, we want everything now. It’s an instant world. And a fat one because of it.
    Thankyou so much for educating the unknowings. Me very much included.

  • Rusty says:

    Thanks for sweet poison it has been a revelation. My partner and I are reading all we can though good info is not easy to come by. Just finished the bitter truth about sugar by Dr Lustig a lot of which was too much for my tiny brain but good to know it is all based on science and how we can see the effects on mice and over time the general population. The personal reactions we have both had since reducing fructose as much as possible just before Easter (good timing I know – but we saw ‘That sugar movie’ and we wanted to change) – Chronic indigestion gone, less period pains, better skin, irritable bowel gone, leg cramps gone, sinus issues gone. We are slowly losing weight and even if there were no other benefits those would be enough. Thank you for telling the truth.

  • […] When using sweeteners, it is all about the content of fructose, as this is the dangerous component of sugar that we want to minimise. I will let the experts on this subject explain why here, and here. […]

  • Paul Verizzo says:

    I know this response to two years later, but it pains me to see “corn syrup” conflated into “high fructose corn syrup.” The former, created by the same enzymatic process differently run, has been around for over a century. In America, think Karo Syrup and Pecan pies. It is 100% glucose, or very close to it. Other being too quickly absorbed, it’s no different than eating starch in any form.

    Since fructose is far sweeter to us than sucrose, “they” figured out how to tweak the process to, in effect, get more sweetness out of corn starch by creating HFCS, the latter being 55% fructose.

    Off you comment, but readers should note that the angelic sounding product of agave nectar is similarly derived almost pure fructose.

  • Theresa says:

    Hi Terence if you don’t mind me pointing out to you having first of all juice which is a definite no no as regards too much sugar then you are having figs and and prunes also not good especially all together you are blasting your body with a sugar high prunes and figs have a lot of sugar especially if they are not the fresh sort . The beer you mention would be acceptable if not overdone .

  • […] and Fructose. Our bodies deal with Glucose quite effectively, but Fructose is a whole other issue (read more on that here).  If you are up for a little light reading, I really, really recommend you get David […]

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