Sugar and Health: Interview with UCSF professor Robert Lustig | Hacker News Reader

Sugar and Health: Interview with UCSF professor Robert Lustig

kqed.org

108 pointskqr254 comments

I just watched the mentioned video[1] the other day and made some notes, so thought I'd share them since this hit the front page.

- Fructose is metabolized similarly to ethanol. Both can only mostly be metabolized in the liver, whereas glucose can be metabolized throughout the body. Both result in a storage as fat of a significant portion of the calories, possibly in the liver, where the fat causes long-term harm. Most of glucose on the other hand is stored in the liver as glycogen, which is not harmful long-term, and is the main source when you're eating a bunch of white pasta (glucose) storing up for a big race.

- If we just ate fructose from fruits we'd eat 10-20% as much as we do today. Plus fiber is protective against many of the negative effects associated with fructose. So fruit is probably on the balance still good for you or neutral in terms of the negative effects from fructose mentioned here.

- Fructose seems to suppress the post-eating dip in ghrelin levels, where ghrelin is thought to be important in encouraging us to eat--the "hunger hormone".

- Fructose doesn't cause a spike in insulin and reduces leptin, which he views as a negative, as it goes along with not discouraging further eating.

- He gave no evidence that glucose is good or beneficial, or reasons why glucose isn't a threat to increased risk of diabetes, etc. He's just chosen his battle as against fructose, as it's more winnable than against all sugar.

That last bullet is my conclusion/wrapup of his perspective. I think his points are valid, and his recommendations are good for an overweight person (ie, your average American), but he oversimplifies things to make his case simpler and stronger. If you're really trying to stay healthy, eating a ton of glucose is not a good thing--an issue he mainly skirts to keep the focus on fructose.

[1]http://www.youtube.com/watch?v=dBnniua6-oM

Listen to the presentation - he mentions glucose specifically, and explains why he thinks it's a toxin, as opposed to glucose, which he calls the fuel of life.

He also mentions that while eating a ton of glucose may make you obese, eating fructose will push you toward metabolic syndrome, which is where most of the health problems lie.

>fiber is protective against many of the negative effects associated with fructose.

Sorry for my ignorance in the subject, but isn't fiber the non digestible part of food? I've read that it absorbs some toxins, but how it can have such a big impact?

It's probably not as simple as just the fiber in fruits protecting against fructose/glucose, but it does help. (EDIT: what I mean is, don't replace fruits with a glass of metamucil and sugar :))

Soluble fiber is just that: soluble in water. In your stomach, it absorbs water and turns into a sort of carb-trapping gel. While the carbs are still eventually digested, the gel slows down the absorption. This is good, because it helps to regulate your blood sugar (not as much of a big spike and drop).

Since blood sugar spikes == insulin response == hungry signals, this is quite useful.

Insoluble fiber is also useful, but mostly just for waste processing.

I have read that fiber helps control your blood sugar levels (by carrying the sugar away before your body can process it), but I cannot find any good references.

Lustig makes a few great points, but it's important to keep in mind there are some who argue he is a "fructose alarmist" and argue it's not as simple as "blaming fructose alone." A good quote from Alan Aragon: "I would add that fiber is only one of the numerous phytochemicals in fruit that impart health benefits. Thus, it’s not quite as simple as saying that fructose is evil, but once you take it with fiber, you’ve conquered the Dark Side."

Some links: http://www.alanaragonblog.com/2010/02/19/a-retrospective-of-...

http://www.alanaragonblog.com/2010/01/29/the-bitter-truth-ab...

http://www.bodyrecomposition.com/research-review/straight-ta...

I personally don't take sides with either. Like most things in the nutritional field, a healthy balance is more effective for me than trending behaviors and ideologies (i.e.: no-fat diet, "slow carb" diet, Atkins diet, etc.).

Did you listen to the linked MP3? If so, I'm not sure how you can listen to that and conclude he's "blaming fructose alone". I'm up to at least three times he's clearly explained why that's not the case. And I don't mean "mouthing words about it then blaming it anyhow", I mean, explaining the ways in which things work together to cause obesity, and how fructose is only the most effective member of a group of 4 foods, and so on.

I really think people really ought to go primary sources and stop listening to people summarizing summaries and then launching devastating assaults on strawmen.

And Lustig, in this podcast, talks about how fiber and fructose tend to go together in nature, which is why whole foods are good as they usually have both. He gives two examples where they don't though... grapes and honey. But he says that honey is protected by bees. But no answer for why grapes make it easy to get fructose without fiber.

Grapes have been domesticated for thousands of years, and at every step the goal has been to maximize fructose and minimize fiber, most notably in making the seedless varieties that comprise the vast majority of table grapes sold today.

At this point, who knows what grapes were originally like? Of course, we know they had real seeds and I'm guessing they weren't so plump and thin-skinned. So maybe they had a much more commendable fiber-to-fructose ratio.

Today, table grapes are just glucose and fructose water balloons.

Wild grapes tend to have large bunches of really small fruit with a few seeds, if I remember right. We had some in our backyard in Livermore years ago.

Are you guys talking about the huge, swollen, purple grapes that are incredibly sweet and juicy? In New Delhi, you only find those grapes at large supermarkets. Most grapes sold here are exactly what you described: large bunches of really small fruit. No seeds, though.

Yes, very large red/purple/green grapes without seeds are the common variety in stores in the US.

Perhaps the evolutionary fitness of grapes was independent of that particular characteristic.

Eating a fruit is not the same as drinking the equivalent amount of fruit juice along with some fiber for the same fructose load, because when eating a fruit the fact that the sugars are bound up in the fibers and must be broken down acts as a rate control.

It's a dose issue, but dose is both volume and absorption rate, and the absorption rate of fructose from free sugar is very fast, as it is not rate-regulated in the liver like glucose metabolism. This means it doesn't require as much refined sugar compared to sugar from fruit in order for your liver to spend some time with a dangerous fructose load;

-Refined- sugars are -especially- problematic, because of the absorption pattern. Simply combining free sugar with supplemental fiber mitigates some of the metabolic issues, but doesn't alleviate the problem.

If you watch Lustig he -does- say the fruit is fine, for this reason.

Whenever we find the chemical in a particular plant that is the one we like the most (and in rats, it's been shown that sugar&cocaine addicted rats prefer their sugar hit to their cocaine hit), extract it, and crystalize it, it's not surprising that it may be problematic.

Here's a 1.5 hour lecture by him on the exact biochemical pathways that make fructose a poison.

http://www.youtube.com/watch?v=dBnniua6-oM

Cliff Notes: Drinking soda makes you fatter. Also orange juice, cookies, and any other highly processed drinks/foods. Avoid these to lose weight.

Also fruit and some other unprocessed things.

he said fruit is okay because it has more fiber content. also to go along with this: he said we don't know enough about artificial sweeteners to conclude whether they're a healthy alternative yet.

That is not correct. If you listen to his talk Lustig said something to the effect of "wherever god put the poison, he also put the anitdote." Thus, anywhere in nature where fructose appears there is also fiber. And fiber if it is processed at the same time and similar quantities as fructose allows the liver to process fructose properly.

So there should not be anything in its natural state that is problematic. The only exception to that may be honey.

> The only exception to that may be honey.

Well, that's because God didn't put it there -- the bees did. :-)

If you personally have to brave FREAKING BEES to get to it then you'll probably moderate your consumption enough ;]

> wherever god put the poison, he also put the anitdote

This should be taken as a tendency, not an absolute rule.

The tendency is, of course, caused by the fact that if it's plausible for any species to have evolved digestive mechanisms that allow them to make good use of a food source that's significantly available over a long period of time, then it probably happened, and become widespread.

But you have to consider implementation complexity (why aren't we immune to ALL poisons and disease that have been around for long enough? why don't we all have lifelong 20/5 vision?) vs. time vs. benefit. That, and a lot of things that could have evolved, haven't yet.

It's not merely that. It also gives you diabetes and hearth disease.

I'm going to reiterate this again on this thread:

Yes, this interview is long, as was the Youtube video from Lustig. But it is worth every minute of listening time.

Watch the original video (linked in this thread) for a more in-depth technical explanation of the cellular processes at work. It's truly fascinating material.

I felt let down by the interviewer interrupting and changing the topic at least two times when I was eager to hear more. The first when Lustig tries to address Alan Aragon's criticisms, he even insists that it is important to follow on it, and the second when he begins talking about the externalities of using public policy to counter the effects of increased consumption. In both cases the interviewer abruptly changed the topic and the arguments were left incomplete. The rest was not news if for anyone that has seen his youtube video.

I recommend this video as a sort of sequel to the points presented by Lustig:

http://journal.crossfit.com/2010/04/insulin-body-weight-and-...

Dr. Connelly expresses broader and more extreme opinions(he doesn't care about fiber, and essentially recommends you drown yourself in protein before touching carbs), but also has a good technical overview of the biochemistry.

Thank you. I found this a lot more useful than the NYTimes article.

Last summer I did a 14-day juice fast (primarily organic vegetable juice).

After about 3 days of no carbs your body burns off most of the sugar in your body (the liver's glycogen stores) and you go into ketosis (http://en.wikipedia.org/wiki/Ketosis) where your body switches its fuel source from sugar and starts burning body fat for fuel.

Some people who go on these types of fasts talk about the mental clarity they receive after a few days into it. I can attest to it -- the best way I can describe it is going from ADD to no ADD.

When this happens I have assumed it has something to do with the change in the brain's fuel source. I don't know if this is related to sugar being toxic, but I have suspected it might be.

I'm curious about this: do you mean you drank only organic vegetable juice for 14 days?

Yes -- I bought a juicer and stared out making it myself, but this quickly became a PITA so instead I went to Whole Foods and stocked up on Bolthouse Farms "The Vedge," which is like V8 only organic (and pretty good).

After about day 3, when all the sugar burns out of your system, you aren't really hungry anymore. Psychologically you may feel the urge to eat because you're used to doing it so often, but you don't really experience the "hunger pangs" like when you miss lunch. This is because "hunger," as most of us experience it, has more to do with your brain craving sugar than it is you being truly hungry.

Did you do this under a doctor's supervision or just on your own?

I hope people aren't reading this and thinking about doing this crazy diet especially with all this misinformation.

Hunger is not just your "brain craving sugar". I get hungry every single day and I eat virtually no sugar.

Yes, insulin response has been known to cause some cravings, but that isn't the only factor in hunger.

Fat and protein also satiate you more than carbohydrates which means you shouldn't experience as much hunger.

"Know the difference between hunger and appetite. According to Chalmers and Campbell, few people understand the difference between real hunger and appetite. "Hunger is more physiological, whereas appetite is more psychological," they state. The authors advise that it may take some time to distinguish one from the other, but eventually, it can be done. So the next time you experience a "craving," remember to ask yourself whether it is hunger talking, or your brain only imagining it needs food. Also, it is important to check your blood glucose (sugar) when you experience these feelings to make sure you’re not low" (Joslin Diabetes Center, Harvard Medical School - http://www.joslin.harvard.edu/info/food_cravings_and_diabete...).

I've also found that sometimes drinking something is enough. If I'm eating lunch, for example, and I've run out of water, I find that sometimes I can end up eating more than I need because I'm actually thirsty, but somehow it registers as more hunger. It's weird.

Isn't there also a lot of sugar in juice, even if it is vegetables, not fruits?

Less; This table is good: http://en.wikipedia.org/wiki/Fructose#Food_sources

Interesting. Could you please post details on what your day to day meals are like when you were on this schedule? Foods you must eat and some you had to avoid. I'm sure others are curious about this as well.

Your description of ketosis is pretty lacking. You never completely stop using glucose as a fuel source. In fact, your brain always has a requirement to get about 30% of its energy from glucose and it takes up to 40 days to get to that point.

You might be wondering how its possible to use glucose as fuel when you aren't eating any glucose, if so, look up Gluconeogenesis.

I don't understand, you ate nothing but juice and assume that is no sugar? It would be a lot of fructose, which would be glucose after getting through the liver.

Fruit and vegetables contains very little fat or protein (most of them anyway) so were do you think your calories came from? There is only one source left.. carbohydrates

That's wrong. There is very little fructose in vegetable juice. And the liver does not convert fructose into glucose, but in a whole bunch of unhealthy chemicals, including LDL.

"After about 3 days of no carbs"

There's plenty of carbs in vegetable juice. Where else do you think the calories would come from?

"The basis of the ketogenic diet is the brain's ability to utilize ketones as an energy source. Ketones include b-hydroxybutyrate, acetoacetate, and acetone, which are products of fat breakdown. Under normal conditions, the brain derives most of its energy from glucose. Under fasting conditions, hormonal changes cause fat cells to release fats, which are then broken down in the liver. The liver packages the energy contained in fat into ketones. The liver releases ketones into the blood, which then transports them to the brain." (Department of Neurology, Washington University School of Medicine, http://neuro.wustl.edu/patientcare/clinicalservices/pediatri...).

IOW the ketosis was from pure undereating instead of not eating carbs, since your calorie intake was mostly carbs.

Yes, it was a juice "fast" as opposed to a pure water fast.

This is the same type of idiotic quackary (semi-truths and lies mixed with anecdotes and bullshit) that makes people turn to homeopathy, turn against vaccines etc.

Let's see what's in that juice you drank for 2 weeks: http://caloriecount.about.com/calories-bolthouse-farms-vedge...

Serving Size 8 fl oz (240.0 g) Amount Per Serving Calories 60 Sodium 450mg Total Carbohydrates 12.0g Sugars 9.0g Protein 3.0g

Carb-restricted diets usually mean ingesting less than 30g of sugars/day. Assuming you ingested at least 1800cal/day, you were ingesting 270grams of PURE SUGAR a moderate amount of protein and 6 times the recommended intake of salt.

None of what you're saying makes an ounce of sense and while you may have lost weight due to caloric restriction, there is absolutely no way your body would have gone into ketosis, and you have absolutely zero credibility talking about anything nutrition-related.

You sure make a bunch of assumptions for being so emphatic. I didn't drink much of it and bought ketone strips (http://www.walmart.com/ip/Reli-On-Ketone-Test-Strip/13037592) to check it periodically -- I was definitely in ketosis throughout the day.

"The ketogenic diet mimics a starvation or fasting state by denying the body the carbohydrate it requires to function normally, and forcing it to metabolize fat. As the fat is metabolized ketone bodies are produced. It is the production of the ketone bodies which appears to play a central role in the success of the ketogenic diet. When the body begins producing ketone bodies it is referred to as the body being in ketosis. It usually takes 3 – 5 days for the body to go into ketosis after starting the diet. Ketosis is readily recognized, because the ketones can be detected in the urine, and can be recognized by a characteristic smell of the individual’s breath. The prophylactic properties of the ketogenic diet build up with time and it may take several weeks before the full effect of ketogenic diet is achieved" (UNM School of Medicine, http://hsc.unm.edu/som/coc/clinics/Ketodiet_eng_10Dec09.pdf).

I just finished a type of low-carb (though non-ketogenic) diet, so I know my terms, thanks.

Again, nothing you're saying makes sense. You said you drank nothing but low-calorie/high-carb veg juice for 2 weeks, but now you say that you didn't drink much of it? So where did your calories come from? Or did you just plain starve yourself with 300 calories worth of veg juice a day?

If you're gonna play the nutritionist and offer people advice, expect to get called out on things that don't make sense.

It was a juice fast (as opposed to a pure water fast), not a juice diet -- calories are restricted, and energy comes, in part, from the ketone bodies (http://en.wikipedia.org/wiki/Ketone_bodies).

And I am not trying to "play the nutritionist" -- I am simply drawing attention to a possible relationship between Lustig's research on "sugar toxicity", the research relating to the effects sugar has on ADHD, and the effects the fast had on my ADD, after my glycogen stores had been depleted.

Here are 3 studies that explain the effects sugar can have on ADHD...

1. Effects of Sugar on Aggressive and Inattentive Behavior in Children With Attention Deficit Disorder With Hyperactivity and Normal Children

"Although the children with attention deficit disorder with hyperactivity were significantly more aggressive than the control subjects, there were no significant effects of sugar or either placebo on the aggressive behavior of either group. However, inattention, as measured by a continuous performance task, increased only in the attention deficit disorder with hyperactivity group following sugar, but not saccharin or aspartame."

Official Journal of the American Academy of Pediatrics - http://pediatrics.aappublications.org/cgi/content/abstract/8...

2. Nutrition in the Treatment of Attention-Deficit Hyperactivity Disorder: A Neglected but Important Aspect

"Attention-deficit hyperactivity disorder (ADHD) is multidetermined and complex, requiring a multifaceted treatment approach. Nutritional management is one aspect that has been relatively neglected to date. Nutritional factors such as food additives, refined sugars, food sensitivities/allergies, and fatty acid deficiencies have all been linked to ADHD. There is increasing evidence that many children with behavioral problems are sensitive to one or more food components that can negatively impact their behavior. Individual response is an important factor for determining the proper approach in treating children with ADHD. In general, diet modification plays a major role in the management of ADHD and should be considered as part of the treatment protocol."

Applied Psychophysiology and Biofeedback - http://www.springerlink.com/content/vr40331382376623/

3. Blunted catecholamine responses after glucose ingestion in children with attention deficit disorder.

"Eating simple sugars has been suggested as having adverse behavioral and cognitive effects in children with attention deficit disorder (ADD), but a physiologic mechanism has not been established. To address this issue, metabolic, hormonal, and cognitive responses to a standard oral glucose load (1.75 g/kg) were compared in 17 children with ADD and 11 control children. Baseline and oral glucose-stimulated plasma glucose and insulin levels were similar in both groups, including the nadir glucose level 3-5 h after oral glucose (3.5 +/- 0.2 mmol/L in ADD and 3.3 +/- 0.2 mmol/L in control children). The late glucose fall stimulated a rise in plasma epinephrine that was nearly 50% lower in ADD than in control children (1212 +/- 202 pmol/L versus 2228 +/- 436 pmol/L, p < 0.02). Plasma norepinephrine levels were also lower in ADD than in control children, whereas growth hormone and glucagon concentrations did not differ between the groups. Matching test scores were lower and reaction times faster in ADD than in control children before and after oral glucose, and both groups showed a deterioration on the continuous performance test in association with the late fall in glucose and rise in epinephrine. These data suggest that children with ADD have a general impairment of sympathetic activation involving adrenomedullary as well as well as central catecholamine regulation."

Department of Pediatrics, Yale University School of Medicine - http://www.ncbi.nlm.nih.gov/pubmed/8559606

Fact check here: in short - the claim is debunked. http://skeptics.stackexchange.com/q/370/96

I don't see how that post in any way contradicts what Lustig has argued.

It's not just about the amount of fructose, it's also about the way that the fructose is carried into our system.

EDIT: care to explain why this was worthy of a downvote?

In short - Wrong. Your link claims exactly the opposite if you dig deeper.

The top stack exchange answer links to an article which states that fructose is in fact a chronic toxin in quantity, but that high fructose corn syrup is no worse than sugar or honey or maple syrup or many other common sweeteners. This is consistent with Lustig's claims. Read it for yourself. http://www.sciencebasedmedicine.org/?p=6501

Lustig claims that consuming a glucose only sweetener, such as maltose or dextrose or glucose should be lead to better health and weight loss when compared to a fructose glucose mix, such as sugar or high fructose corn syrup.

Speaking from my personal experience, I lost 3 inches off my waist while exercising less over a period of 2 months after switching all fructose sources EXCEPT whole fresh fruit out for dextrose.

The top reply is addressing whether HFCS is more dangerous than other sweeteners rather than the claims Lustig makes. Lustig agrees that it's not more dangerous than something like table sugar. What he is saying is that fructose (whether from HFCS, sucrose, agave nectar, etc.) is toxic in sufficient quantities.

So this isn't really debunking anything and it's actually in line with what Lustig says.

Reply on news.ycombinator.com