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The following was shared recently on a list-serve I am on and is a response from Dr Lustig himself on why fruit is not really the problem when discussing fructose and its potential problems. Much of his research focuses on the health issues of fructose.

In Heath
Jeff


Quoting...

"The reason that fruit is OK is because it has way more fiber than fructose. Fiber slows absorption of glucose, fructose, and fatty acids from the gut, while increasing rate of transit (to generate the satiety signal earlier). Plus its effects on satiety.

The rate of fructose absorption determines how fast the fructose will hit the liver. The faster it reaches the liver (since the liver has a fixed capacity for extraction and metabolism), the more likely the liver will be overwhelmed by the excess. If the liver is overwhelmed, the mitochondria will not be able to metabolize it, and more will get converted back to citrate, and therefore more will end up as liver fat, causing insulin resistance.

Also, if the amount of fructose is truly excessive, the liver will be unable to extract all of it from the portal vein, meaning some of the fructose will make it into the systemic circulation; where it can contribute directly to protein glycosylation (a process I didn't discuss in the talk for lack of time), and arterial stiffness and atherosclerosis.

So how much and how fast the fructose hits the liver determines whether it will have detrimental effects.

Fiber in fruit limits the volume of fructose consumed (through satiety) and the rate of absorption. Thus sparing the liver.

Hope this makes sense.

Sincerely,
Robert Lustig, M.D."

And from another interview...

"Each sucrose molecule consists of one molecule of fructose joined to one molecule of glucose. In the gut, these two components are quickly split apart. High-fructose corn syrup is a less expensive mixture of glucose and fructose. There is no point in belaboring the difference, Lustig says. “High-fructose corn syrup and sucrose are exactly the same,” Lustig says. “They’re equally bad. They’re both poison in high doses.”"

Hi Jeff,

I want to make sure I understand this correctly, so I'm going to pose a hypothetical question. If a person eating bananas were sated after consuming 5 bananas, but continued to eat 5 more bananas, that would be damaging to the liver (according to Dr. Lustig)?

From the book, Prevent and Reverse Heart Disease, by Dr. Caldwell B. Esselstyn, Jr. M.D., page 71:

"Fruits of all varieties are permitted. A word of caution is in order, however: it is preferable to limit your fruit consumption to three peices a day."

Be well,
-dog

From the book The McDougall Program for a Healthy Heart, by John A. McDougall, M.D., page 75: (listing items comprising "The McDougall Diet," in the context of preventing heart disease):

"Fruit, fruit juice and dried fruit - limited to two to three servings per day."

Please note that this is followed by a caution, on page 76:

"My recommendation: Avoid fruit, fruit juice, and other simple sugars if your blood triglyceride level is above 150 mg/dl or if you have heart disease, high blood pressure, or diabetes."

Be well,
-dog

No one here is recommending 525 or 1050 calories from fruit.

If you haven't read this thread from the beginning, you may want to, as I addressed this issue earlier on.

In Health
Jeff

Hi Jeff,

Thanks for taking the time to respond. I did re-read the entire thread on your recommendation, and did not find my specific question addressed. To be fair, I may not have been very clear in my question, and I hope you will permit me to have another attempt:
After reading your quote from Dr. Lustig, I was reminded of a previous high fruit diet that I was on (which I do not recommend), where I would eat fruit beyond my satiety in order to get enough calories. Unfortunately some of my friends are still on such a diet, and the quote you posted from Dr. Lustig seems to indicate that eating fruit beyond satiety makes heavy demands on the liver, for which further health problems may arise. I would like to know if I am interpreting that correctly (in your opinion), as I am looking for further evidence to present to my friends to help lead them towards a healthy diet like this one, which includes lots of fresh fruits, vegetables, and starches.
Thank you for taking time to respond Jeff, I read all of your posts with the anticipation of furthering my understanding of healthy eating!

Hi Russ,

Thanks!

I do not see where Dr Lustig is making that comment so I would disagree with your interpretation.

So, lets review..

1) I do not recommending arguing the merits of one diet over another with friends, nor do I choose to participate in such discussions. If you have someone who is truly interested, send them here so we can interact directly.

2) My earlier comment about the mango's applies here also. We are not recommending anyone consume that many fruits or to get that many calories of their day from fruit.

3) I am not recommending anyone to consume food beyond satiety to get enough calories, so my first recommendation would be not to do it. If someone has to do it, then there is something wrong with their diet or the amount of energy they are expending.

4) 5 small bananas contain about 25 grams of fructose. 10 medium bananas would contain about 50. In the earlier posts, I showed that there really is no problem with fructose, even if it is straight pure fructose, until the amount gets over 50 grams and the real concern starts with levels over 100 grams.

So, again, while I would not recommend anyone do what you are asking, it is unlikely that their would be an issue to the fructose content.

In Health
Jeff

So the main concern is with refined sugars since they have no fiber or nutrients to give your body a signal to stop eating. It would be hard for most people to consume 5 bananas, much less 10 in one setting because of the volume of food but the same amount of calories from a soft drink would be easy to consume.

Michael

Jeff,

Can you answer this?

If you read the above you get the impression that if you have heart disease you should avoid fruits. I would think 2-3 servings of fruits should be actually good as they are rich in vitamins and minerals also helps in calorie density.

Can you comment as to why Dr McDougall recommends no fruits for CVD patients.

Correct!

In Health
Jeff

Thank you very much for clarifying that for me Jeff! All of your points are well taken, and I will especially have to work on number 1

Well, the less sugar consumed of any kind, the potential for a lower a1c but in regard to fructose, as I said here in my earlier discussion with you in this thread.



We should not judge a substance from any one aspect of it so while the effects of fructose on a1c appears to be beneficial, its effects on the rest of the body is potentially harmful so no matter what, the less the better.

In Health
Jeff

Having recently discovered Dr. Lustig... I understand that he does not advocate the consumption of fruit juices (fruit with the fiber intact, though is healthful). I am wondering if there is a difference between drinking fruit or vegetable juice where the fiber has been extracted and discarded (via a conventional juicer) and drinking liquified fruit and vegetable juice ('a la Vitamix) where the fibrous parts are distributed throughout the liquid? Thanks for your thoughts on this matter.

The whole food is always better than the blended food.

viewtopic.php?f=22&t=15419

In Health
Jeff