T Nation

Fructose - Scientific Data


This sure opened my eyes. This dude (Dr. Johnson) knows his shit about sugar.

In this video series, Dr. Richard Johnson and Dr. Joseph Mercola discuss ties between fructose and uric acid (VERY INTERESTING) and how they relate to metabolic effects such as kidney disease, diabetes, high blood pressure, fatty liver, etc etc.

"Fructose is the #1 risk factor for obesity" Dr. Johnson (You've really got to listen to the video to appreciate this comment)

1) http://www.youtube.com/watch?v=ZjG5t4LN0jA

2) http://www.youtube.com/watch?v=JUMtrs8vW2Y&feature=player_embedded
(@6:00 differences between HFCS and Table sugar discussed) (@6:00-8:00 - Fatty liver from HFCS due to speed of fructose absorption) (@8:00-9:00 it's the major cause of fatty liver disease)

3) http://www.youtube.com/watch?v=XGlyCy7Ii3k&feature=related
(@~0:45 - clinical studies in humans validating what we've seen (in rats)) (@2:00-3:00 - Dr. Johnson suggests a sugar tax and poses a strong argument, and also suggests a warning label for sugar containing foods!)

(@~2:35 - "If you take two animals and you feed one fructose, and you feed the other one the exact same number of calories, but given as dextrose or glucose, it's only the fructose fed animal that will develop obesity, insulin resistance, fatty liver, high triglycerides, signs of inflammation, vascular disease, and high blood pressure." ~Dr. Richard Johnson

...Could this be true!?!?

...He says he just completed a clinical trial that confirms this. Drugs are more effective at reducing uric acid, but sugar reduction is critical as well.)

(@3:10 - Discussion of removing fructose from GRAS list -- sugar should not be banned, but we should educate the ppl as to why restriction is necessary) (@6:40 - as fruit ripens it will be higher in fructose and lower in antioxidants, animals use this technique to get fat for the winter, the loss of vit C in fruit probably has evolutionary ties) (@7:30 - 25-30 grams of fructose per day is the recommended amount, but the less the better for sugar as a whole) (8:30-9:00 - fructose causes insulin resistance - for the same level of blood glucose, you have a higher insulin level; "YOUR TISSUE BECOME RESISTANT TO INSULIN!!!"; new data that fructose injures the pancreas itself; ...plays a role insulin resistance and eventually diabetes) (@9:10-9:27 - "Interestingly, when you eat glucose, you stimulate insulin levels, but we don't necessarily think that's bad because... insulin has a purpose ant that's to help move the glucose into the cell; You're not actually inducing insulin resistance with glucose)

4) http://www.youtube.com/watch?v=JUOqPyrbkwk&feature=related
(@1:00 - It can be reversed) (@~2:30 - glucose accelerates fructose absorption!) (@~2:58 - Individual differences in fructose absorption; "the transporter that takes on fructose is turned on by fructose!!!") (@4:55- PPL get more and more sensitive to sugar the older they get - will be submitting a paper on this shortly) (@ 5:50 - 9:04 - "Fructose is the #1 risk factor for obesity"...and other foods that increase uric acid have a synergistic role... and guess what the #1 food is.... hold your hats and don't shoot the messenger.... it's beer! FML! Beer belly = metabolic syndrome! -- This is Dr. Johnson's observation, but the uric acid story remains a very controversial story, but a lot of scientists are starting to realize it could be the case, and a lot pilot studies are now in the works to give credence to this))

5) http://www.youtube.com/watch?v=iEjJ7nnYxLs&feature=related
(0:00-0:45 - the PHDs are still debating the science, ...no big news here) (@~1:40-2:20 "The purpose of the content (of the website) is that as a physician, I realized that, many years ago, that there's this lag time between the time that something is clinically appreciated by really amazing hard working researchers and scientists who understand how profoundly important concept, and that concept may take 10, 20, 30, 40 years before it's widely adopted and accepted."


Both docs are great in my opinion. Sugar-the bitter truth, was the video that opened my eyes about fructose. But these are great too.


How coincidental: Just today in class we had to watch a video called "King Corn" about how the majority of corn grown in the USA is purely for feeding our cattle and making HFCS.

While I agree with the problems HFCS causes, I was then forced to listen to my whole class who all know very little about nutrition, especially my 300lb professor. And one girl who was very proud of the fact she has not eaten a burger or any beef in 11 years.


Yeah but how much can she DL?




Okay, in response to one part of the post summarized and the video. He talks of the increase of glucose intake causing increased absorption of fructose; however, what he also fails to mention is this happens with any high carbohydrate (HC) or high fat (HF) diet. Very briefly, the Sodium-Glucose transporter (SGLT; responsible for glucose absorption) is upregulated in response to a HC or increased sucrose intake. I believe the same is true with saccharin as well and its effects on SGLT. The same goes with enzymes responsible for metabolism of fats and fat absorption and HF diets.


Sugar-The Bitter Truth is a garbage, sensationalist, and alarmist video designed to influence masses of people who don't have any real understanding of science or nutrition.

This interview however has a lot of merit to it if taken into the right context and viewed with a critical point of view. This doctor tries to remain as factual as possible and ackknowledges the fact that a lot of his work is still in the theoretical stage and has lots of opposition. What he does get right is:

  1. People should limit their intake of fructose = don't over consume table sugar, HFCS, or any high processed carbohydrates. Cutting refined sugar intake by 2/3 is a good recommendation.

  2. The dangers associated with fructose remain to be dose dependent and that the problems really occur at high doses. He mentions that the problem isn't the sugar itself but the amounts being eaten by most people.

  3. People shouldn't avoid fruit since they are high in antioxidants/vitamins/phytochemicals/fiber that make up for the minor fructose content (~8g a fruit). 3-4 fruits a day is acceptable intake.

  4. Fructose in high amounts is likely a contributing factor to many diseases and obesity.

  5. High amounts of fructose is a negative nutrient partitioning agent.

  6. The fructose in HFCS and the fructose in Sucrose act almost the same in the body with the POSSIBILITY of slightly faster absorption kinetics for the unbounded fructose in HFCS.

However, what isn't necessarily true, is unmentioned in the video, or should be looked at with a critical viewpoint:

  1. The whole uric acid/disease/obesity relationship. He rightfully admits that it is a hypothesis at the moment.

  2. That animal studies are often not the best designed and rats (the most common animals used) have very different carbohydrate metabolisms than humans.

  3. Dosing schemes in many of the studies are almost unrealistically high and represent very high consumption of fructose. Again, this doctor points out objectively when he mentions a critical trial that the dosing scheme was over 2 times the amount of fructose the average American consumes.

  4. He says that fructose is the MAIN factor in obesity. Too large of a claim with WAY too little substantiation or evidence.


Agree completely.


If you weren't from Wisconsin, I would have thought you were describing my nutrition courses. Most of my peers are either overweight or far too thin and pale. Future dietitians of America!


Josh I agree with most of your post, except the part about the video being garbage (but who cares this is opinion) and number 6...

From what I've read, the fructose in HFCS is not only unbounded, but also mostly D-fructose which is more likely to be stored as triglyceride because of the amounts it comes in at, and that in nature D-fructose exists in very small quantities.

HFCS majority is D-fructose, while majority in Fruits and nature is L-fructose, which is supposedly handled much better in our body


D-fructose is what is found not only in HFCS but in fruits, honey, etc.

I know there are popular articles stating differently.

It seems that people like the letter "L" and like to stick it in front of things: I've even seen supplements labeled as being "L-Taurine" as an illustration of this, as well as articles about taurine using that wrong nomenclature. But it is not the case that everything natural is L.

Hence, the articles you've seen claiming what you stated.


The fructose in HFCS being "unbound" is irrelevant since the bonds that hold glucose and fructose together in sucrose are broken in the stomach before the sugars are absorbed in the small intestine. This has been discussed here before.


The sugar the bitter truth is not a bad video if you take it in the right context also, the biochemistry is sound and he demonstrated that the effects of fructose are indeed dose dependent, what I see most people complaining about his video is the alarmist nature and delivery of his presentation but you got to remember that this is a endocrinologist who has to deal with parents who let their kids drink fruit juice all day long because they think its healthier than soda and don't understand moderation thus his delivery.


Good thread, and what josh says i completely agree with. Fructose being the main factorn obesity are you shitting me?

Couldnt we agree the reason everybodys fat is overconsumption of calories and lack of activity. The overconsumption of required energy coming from majority of the time - fat - which is calorie dense and therefore contributes mainly to people overindulging on food, even when they think they dont eat much. Its when they eat on couch and eat fast food or snack of lollies/chips/chocolate all of which are small but high in calories.


I personally know quite a few fat phobic, sugar holic vegetarians that are quite fat for the amount of calories they take in on a consistent basis compared to their body mass and sure they would lose body weight by eating less but they don't eat that much in the first place. I am sure that they would have better body composition if they ate a diet that was moderate in protein fat and carbs even if this moderate diet is somewhat higher in calories than what they were eating in sugar.


Designed to influence them to eat less sugar? Yes, how horrible.


I don't agree with that. Most of the food problems in America aren't a matter of calories, they're a matter of food quality and timing. Reducing lipid intake hasn't resulted in Americans losing weight -- if the probem is the -fat-, shouldn't obesity have done down, instead of up, as dietary fat consumption declined?


Agreed. Problem is, you -need- to be alarmist with people on this issue. Considering that sugar is in every damn thing, and temptations for shitty food (vending machines, advertisements, etc) are everywhere, telling people "Limit your sugar intake" isn't enough. You more or less have to tell them to avoid sugar religiously in order for them to only consume a moderate amount.


Horse shit.

Americans HAVEN'T reduced lipid intake. Your statement should read "telling Americans to reduce lipid intake hasn't resulted in Americans losing weight."

GO check up on the statistics, fat intake has RISEN along with sugar intake AND, shocking for you thermodynamics experts out there, total caloric intake.

"Simply a matter of food quality and timing", eh? I've got a bridge to sell you.


More horse shit. Simply limiting sugared drinks and desert type items would drastically cut sugar AND calorie intake.

Stop trying to defend pseudoscience and extremism with more pseudoscience and extremism.