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Medical Accepted medical opinion regarding fructose

  1. Mar 24, 2017 #1
    I am asking about what is the accepted medical opinion regarding fructose - and specifically whether there are common conditions when it should be avoided?

    My interest started about a year ago when my doctor said that I was glucose-intolerant and that I should avoid foods with a high glycemic index. There was some ambiguity in the details, so I saw a nutritionist and got some specific diet guidance.

    As I approached a birthday this year, I decided I would prepare a birthday cake for myself that would be healthy for all members of my family - allowing for food allergies and glucose intolerance's.

    I needed a good substitute for sugar and with a little research I quickly discovered that High Fructose Corn Syrup had about the same amount of glucose as sugar - and as it turned out roughly the same amount of fructose as well. So I decided on fructose: 70% sweeter that sugar, no glucose, works similarly to sugar while cooking.

    Fortunately, I had to mail order the fructose because that gave me time to further research fructose. And I found many articles with varying opinions - everything from "poison" to simply "watch calories". One item was this 2011 thread: https://www.physicsforums.com/threads/high-fructose-corn-syrup-hfcs.479962/

    So, is there an accepted medical opinion of fructose - and if there is, what is it?

    One item (the one that casts fructose as a "poison" is this:

    In that video (90 minutes long), Dr. Robert Lustig says that fructose is only metabolizes by the liver and the results are not good - especially if you (as I am) glucose intolerant. He specifically counts it as a cause for Type 2 Diabetes.

    Are Dr. Robert Lustig views mainstream?

    Thanks
     
  2. jcsd
  3. Mar 24, 2017 #2

    DaveC426913

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    All foods are, to a greater or lesser degree, partially good for you, partially not good for you.

    An orange might contain as much sugar as a chocolate bar, suggesting to the uninformed that it might not be good for you.
    But an orange provides many, many more micronutrients, macronutrients and fibre, and that is what makes it good.

    Food is a balance - a compromise of competing needs. As with all things, moderation and balance are key.

    The reason fructose is relatively unhealthy, compared to other sugars, is because it is a simple sugar - very easy to absorb and digest, which means your body has to do very little work to extract the energy out of it. That leads to storage rather than expenditure.

    The real problem with fructose is the sheer quantity of it added to everything we eat.

    Words like 'poison' - in the context of foods - are sensationalist.
     
  4. Mar 24, 2017 #3
    What's "added to everything we eat" is sugar (sucrose) and High Fructose Corn Syrup (HFCS). Both contain roughly equal parts fructose and glucose. HFCS is added to food because it is inexpensive and roughly equivalent to sucrose in taste, calories, etc.
    Over 500 years ago, Paracelsus said "All things are poison and nothing is without poison; only the dose makes a thing not a poison." (or the Latin equivalent).
    Still if Lustig's descriptions are correct, there is a vast difference between the toxic potential of fructose and glucose.
    He has 125 articles listed in PubMed: https://www.ncbi.nlm.nih.gov/pubmed?term=Lustig+RH&cmd=DetailsSearch

    That is at odds with Lustig's descriptions. His description is that both glucose and fructose are easy to digest and pass readily into the blood stream (perhaps limited by other stomach content). Organs can then readily turn the glucose to useful energy, but (per Lustig) only the liver can deal with fructose - and "very little work" doesn't really describe that process very well.
     
  5. Mar 24, 2017 #4

    Evo

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  6. Mar 24, 2017 #5

    jim mcnamara

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    Glucose intolerance is the hallmark of pre-diabetic patients, Type II diabetes. This is usually part of a set of patient conditions, called metabolic disease in the US.

    Type I diabetes is an autoimmune condition that kills insulin producing cells - the Islets of Langerhans. Type I is usually early onset. And is generally unrelated to diet. Type II used to be a disease of middle age, it now has becoming prevalent in young people, teenagers. It is considered to be strongly related to bad diet and lack of exercise. There is a genetic component to Type I; to a lesser extent Type II.

    One other point - carbohydrates like starch, sucrose, fructose, glucose ALL have high Glycemic Indices. They all impact blood sugar levels. White potatoes, pasta, white rice, white flour products -- all fall into this category.
     
  7. Mar 24, 2017 #6

    DaveC426913

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    Yep. Nothing more sad than an Irishman having to avoid potatoes. :H :H
     
  8. Mar 25, 2017 #7
    First of all, thanks for the reply - I was waiting for your input.
    The article that you cite, Patrick Skerret, Harvard Health Publications, 2011, is certainly evidence that Lustig's ideas are either mainstream of becoming mainstream. That article links to the same video as I posted in the OP. I particularly found the two closing paragraphs interesting:
    It appears that Lustig is contributing to the effort to "connect the dots between fructose" and MetS. Here are some of hie recent PubMed listings of his research:
    October 2016: https://www.ncbi.nlm.nih.gov/pubmed/27451002By substituting glucose for fructose they conclude (n=37):
    February 2016: https://www.ncbi.nlm.nih.gov/pubmed/26499447Concludes (N=43):
    March 2013: https://www.ncbi.nlm.nih.gov/pubmed/23283181Summary of Review:
    I did find an article that contains most of the information in the video: http://advances.nutrition.org/content/4/2/226.long. The big advantage to this article is that it includes tons of citations. On the other hand, it's missing some incidentals (ex, the Coca Cola review) from the talk.
     
  9. Mar 25, 2017 #8
    From the Calorie Control Council http://caloriecontrol.org/fructose/:
    A word of caution: In that last quote, they are setting the GI of glucose to 100. In most diet guides, white bread is set to 100. The conversion factor is about 1.5, as seen in this table that lists both: http://ajcn.nutrition.org/content/76/1/5/T1.expansion.html.
    So this would put fructose at a white-bread-based GI of roughly 29. Any diet guide would consider this a low value; for example:https://blog.iafstore.com/en/glycemic-index-and-glycemic-load-of-foods-a336. By the way, that last source shows fructose with a GI of 32, but does not cite a source.

    To the rest of your point, starch, sucrose, and glucose do have high GIs.
    And that makes fructose look great for someone with MetS who is told to avoid high GI in their diets. So I bought 2 3-lb bags of fructose - which I may now dump. I used some of it to make a cake - and the cake has a fructose-to-fiber ratio that is lower than most fruits. But based on those isocaloric studies, it's looking to me as though I would have been better off using regular sugar.
    I have set up another appt with the nutritionist (my doctor has handed this off to her), but I am not fully confident that she is well-enough briefed on fructose.
     
  10. Mar 25, 2017 #9
    Have you considered a sugar substitute like Stevia which can be used in baking? Only problem some people perceive that it has a bitter taste.
     
  11. Mar 25, 2017 #10
    I have always shied away from artificial sweeteners - on the basis that making the body think that it was about to get calories when it wasn't couldn't be a good idea. More recently, there have been articles such as this one: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3772345/.

    Also, I find the blood glucose pretty apparent. Not only do I feel satiated after eating calories, but I think and work better. I have a sense of "enough calories". So I'm looking for "enough calories" without MetS. The prescribed method for this is to make the glucose supply from food slower and steadier.
     
  12. Mar 25, 2017 #11

    jim mcnamara

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    @.Scott yup. You are correct. My bad. I should have read what I wrote. However, GI notwithstanding :
    from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2682989:
    In English the above says: fructose impacts blood fats called triglycerides. Substantially. Next. Are triglycerides bad for those with metabolic disease?

    from: https://www.nhlbi.nih.gov/health/health-topics/topics/ms
    [section on list of risk factors in metabolic syndrome (disease)]
    Being on that list means triglycerides are contributory to future really bad news. If your physician specifically told you to use fructose, go for it. I'd guess s/he did not do that....
     
  13. Mar 25, 2017 #12
    All my physician said was to avoid foods with high glucose index - to get my calories through other means. The same with the nutritionist. What they didn't say was that fructose should be avoided as well.

    But the more I look at fructose (and therefore sugar and HFCS), the more it seems as though it would be worse for me than glucose.
     
  14. Mar 25, 2017 #13

    jim mcnamara

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    Good conclusion. @.Scott I used to be current on all of this because I had several diabetic Type I kids. I'm not diabetic at all. From early on, most articles indicated that simple carbs (monosaccharides and some disaccharides) were not a great choice, but were unavoidable in fruit, which you should eat. So the diabetic exchange diet was born. 1 Fruit exchange (about an apple or a pear) per meal maximum usually. 15g - circa one teaspoon. Fructose counted, too, back then. Still does on the exchange diet.
     
  15. Mar 25, 2017 #14

    Evo

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    @.Scott, I am so glad that you started this thread, I have a number of illnesses where I really need to be watching my fructose intake. Very timely as a friend of mine was just told yesterday to try the fodmap system of identifying foods that may be aggravating his IBS, which I also have.

    Can you get referred to a Registered Dietitian Nutritionist instead of a plain nutritionist? RDN's are required to have more advanced degrees and ongoing certification than a nutritionist that may have little to none. If you are serious, and it seems you are, I think the RDN would be the better choice.

    I'm finding out so many of the foods I thought were good are actually bad for me, I'm having to rethink everything. I also have Metabolic syndrome, among other problems, of course one food that's good for one condition is bad for another. I won't go into the list, but right now it appears the answer is to just stop eating. :eek: :oldcry:
     
  16. Mar 25, 2017 #15
    I didn't know there was a difference between an RDN and a nutritionist. The one I went to works at Lowell General Hospital. I will check to make certain she is an RDN.

    And I am glad you find the thread useful.
    I hope many others do as well.
     
  17. Jul 16, 2017 #16
    Just as a follow-up:
    My nutritionist is an RDN. More precisely, the letters after her name are MS, RN, LPN. She said that the Lustig research is very much mainline.

    Her advice was to avoid large amounts of added sugar and HFCS in my diet.
    I have found it easier to just avoid those entirely. And the extra sweetness of fructose (HFCS and sugar) is starting to taste unnatural to me. Per doctors orders, I am also on a low glycemic index diet.

    That together with exercise (mostly walking) has had yielded good results. HbA1c: last year 6.1, now 5.6. Triglycerides: last year 234, now 118. All current blood work results (Chol, HDL, LDL, HbA1c, Trig.) are in the normal range.
    My primary concern now is whether the exercising is sustainable. Spring is easiest with mild temperatures and lots of daylight. Summer is often too hot for me to tolerate - but I squeezing it in when I can. Fall and winter are the problems. There are very few sidewalk in the town where I live and the traffic is very dangerous for pedestrians in the dark.
     
  18. Jul 16, 2017 #17

    Evo

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    Thanks for the follow up, and good luck!
     
  19. Jul 16, 2017 #18

    jim mcnamara

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    Great posts, .Scott. Time roll up the curtains on a good thread.
     
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