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Welcome all seeking refuge from low carb dogma!

“To kill an error is as good a service as, and sometimes even better than, the establishing of a new truth or fact”
~ Charles Darwin (it's evolutionary baybeee!)

Sunday, May 27, 2012

Great Interview on Fructose ~ The "Other" Side

This one is too good just to tweet.  One of those gems I mentioned the other day is David Despain's Evolving Health blog.  He's been posting quite a bit of late on fructose.  His latest:   Fate of fructose: Interview with Dr. John Sievenpiper.

It's definitely worth reading the whole thing, but I'll excerpt a few things that address the problems with many of the fructose studies and problems with them, and some nice correcting of Lustig & Co.:
  • The 50th percentile for intake in the United States is 49g per day, which is just a little less than 10 percent per day of energy from fructose. ... the 95 percentile for intake for NHANES for fructose consumes 87g of sugar or little less than 20 percent energy.
It seems to me that sugar consumption in the US is often inflated, and the inflation is done by those who seem to have an "crisis agenda" -- by that I mean looking to whip up a crisis for the purpose of enacting legislation or finding a new tax revenue stream. So related to the quote above, Sievenpiper takes issue with the "superphysiological doses" of fructose used in most studies.
  • ... animals metabolize carbohydrates differently than do humans. In animals on a high-carbohydrate diet not providing excess energy, you find that de novo lipogenesis [conversion by the liver to fatty acids] is anywhere from 50 percent or higher.  ... In humans, it is very, very hard under isocaloric (neutral energy) conditions, let alone in overfeeding conditions, to push that beyond 10 percent or even 20 percent.
Ahh yes good old de novo lipogenesis something we've discussed here pretty much ad nauseum ;-) Just related to carbs in general, hepatic DNL has been shown to be quite a bit lower than even the 10 percent and amounting to only a few grams per day in humans. While it is true that fructose is the most lipogenic carbohydrate, that term has been used out of context (and more recently moreso) by Gary Taubes to infer that it's somehow more fattening.  This is clever science journalism, but neither good science journalism nor good science.  For starters DNL is an energy intensive process so would come at a significant caloric cost vs. just ingesting a fatty acid.  We've also discussed the small contribution of DNL to VLDL triglycerides produced in the liver.  Much of this work is fairly settled fact -- this is why it is so frustrating for me to continue to read/hear how it is carbohydrates that make triglycerides and that any significant amount of carbohydrate is turned to fat after a meal.  While fructose does upregulate DNL, sometimes 10 or 20X I've read for a period of time.  But when you're talking about a process that normally produces a few grams of fat over the course of 24 hours, it's still not all that significant.  

This is the most important point, IMO, because it pretty much destroys Lustig's comparison of fructose to alcohol, and I'll borrow the graphic from Despain/Tappy:
  • ... OK, let's look in humans and not animals; let's look under basic normal energy balance conditions, and let's use the best or most elegant tools we have, which are stable isotope tracers -- this is the answer you get: 50 percent glucose, 25 percent lactate, greater than 15 percent to glycogen. These may vary a bit just based on the rest of the background diet and activity level of the organism or human in this case. But in general, this is the fate of fructose.
This is one of those "wow, just wow" moments.  Lustig is unequivocal -- though he does sometimes mention the dose issue -- in his equating of sugar with alcohol and how it is toxic, toxic, toxic!!!  It seems to me that none of the products of fructose metabolism are toxins.  Period.  Greater than 90% goes to glucose, glycogen or lactate.  Oh, and anyone interested in making their head spin over the lactate might want to check out this paper I just parked over in my library.

Last, but certainly not least, Sievenpiper takes on the cause of obesity and the role of fructose:
  • Is it true? [that fructose is a fattening poison]  What we found was that it wasn't. We looked at bodyweight -- which is the Annals [of Internal Medicine] data that you’re aware of -- in each case there was no effect of fructose when it was isocalorically exchanged. There was no adverse effect on bodyweight, blood pressure, or uric acid.  We do see a very consistent and strong effect on bodyweight when fructose is providing excess energy.
Remember the Havel Study Gary Taubes used to demonstrate that excess starch doesn't cause insulin resistance?  Oh wait, he didn't mean to show that, but that was the effective outcome that the glucose beverage drinkers demonstrated.  But the study did show that when you intend to replace 25% of the energy intake of obese/overweight adults with pure fructose sweetened beverages to the tune of over 600 cal/day = 175g fructose/day, free living humans do not compensate for the liquid calories by reducing intake of other foods by that amount.  Indeed their total caloric intake increased by some 200 cal/day during the course of the study and they gained weight.   So already overweight/obese people who start taking in large amounts of fructose sweetened beverages tend to increase intake and exhibit symptoms of insulin resistance (and perhaps leptin resistance?).  

Sievenpiper and Despain go on to discuss some actual benefits of fructose consumption in the form of fruit on glycemic control.  Go check it out!   Hopefully as more folks like this will speak out and we can turn this tide of more bad bastardization of science around.  As discussed in this interview, there are dietitians and docs now counseling clients and patients against even fruit consumption.  Let's not forget 15 year former(?) vegetarian Zoe Harcombe's crusade against Big Fruit & Veg, because we all know 5-a-day has caused the obesity epidemic, right?   Having determined that Lustig's video availability was a browser issue on my end, and now having watched parts 1 through 3 of his new series, I'm pretty thoroughly disgusted with his delivery and material.  He gets basic facts wrong and no doubt these will get picked up and repeated by the Michelle Obama's of the world crusading to reverse this obesity epidemic.  

Sugar and fructose per se are not the cause of the epidemic.  As kids we had access to sugar, indeed there were no sugar-free alternatives.  We (and when I say "we" I don't generally include me as my mom was the health nut in the neighborhood) used to eat sugar straight from straws, fruit roll-ups, Hostess cup cakes daily for dessert at lunch, cookies, Sugar Frosted Flakes back when sugar could be on the label, etc.etc.  What has changed?  Lifestyle and exposure/availability of these foods -- to both children and adults.  Please, please, please. We don't want to replace the ill-conceived demonization of saturated fats that brought us the single greatest assault on human health in human history -- margarine -- with an equally ill-conceived demonization of sugar.  

17 comments:

Franziska said...

"But the study did show that when you intend to replace 25% of the energy intake of obese/overweight adults with pure fructose sweetened beverages to the tune of over 600 cal/day = 175g fructose/day, free living humans do not compensate for the liquid calories by reducing intake of other foods by that amount."

Bingo! I tell my patients that the brain simply doesn't register liquid calories the way it does with those coming from foods. Fruits and vegetables aren't the problem and never will be. I eat fruit with almost every meal and remain at a good weight with very low triglycerides. Thanks for the link to David's blog -- great stuff!

Your childhood food memories sound very similar to mine, except my mom packed Dolly Madison Zingers instead :)

Franziska said...

Actually, I guess it's your childhood memories of what was around, not necessarily what you ate. Obviously my mom was no health nut ;)

KD said...

Franziska brings up something that I'm curious about myself. I think it's right and makes sense that cutting out liquid calories is a big help for maintaining and losing weight. But has there been a study of just that intervention- as in keep eating as you normally would, but stop drinking any calories. Is there any sense of the long and short term results?

Susanne said...

I just finished watching part 3 of Weight of the Nation on YouTube and one of the experts mentioned the "liquid calories don't register" effect with regard to soda, so it's probably been studied. It might be mentioned in Wasink's (sp?) book or in the citations, it sounds like his kind of thing. I don't have access to it here but most libraries will have it.

pbo said...

With regard to soda.

What about orange juice or even milk. This past week, I reintroduced liquid calories, other than the kombucha I sometimes drink.

I must say including a full glass of milk or OJ seems to fill me up if I include it in my meal. So I wonder what if the study differentiates between these types of liquid calories... probably not.

ivat said...

There was a study by Haber et al in 1977 which suggested that apple juice "favours overnutrition" in comparison to the equivalent amount of whole apple. Fransizka says "I tell my patients that the brain simply doesn't register liquid calories the way it does with those coming from foods". Similarly, Haber's abstract says "Fibre-free juice could be consumed eleven times faster than intact apples and four times faster than fibre-disrupted purée. Satiety was assessed numerically. With the rate of ingestion equalised, juice was significantly less satisfying than purée, and purée than apples. Plasma-glucose rose to similar levels after all three meals. However, there was a striking rebound fall after juice, and to a lesser extent after purée, which was not seen after apples. Serum-insulin rose to higher levels after juice and purée than after apples".

Sanjeev said...

From memory, Dr. Wansink doesn't get much into details on chemistry and doesn't differentiate a lot between solid and liquid foods

For example he places equal significance on getting small glasses and small plates.

The theatre popcorn overfeeding study for example compared to the endless soup bowl study are basically the same thing from a behavioural perspective.

Sanjeev said...

Kessler may focus on liquid reward vs solid reward; were you thinking of Dr. K. but typed Dr W?

IMHO if we're talking food reward, solid food has many more variables that allow industrial designers to maximize reward.

texture/mouth feel, "meltingness"[0], crunchiness, stickiness, taste heterogeneity, release of different odorants/flavours based on how long the stuff has been chewed

Then there's the visual presentation (which affects caloric intake as Dr Wansink also documents; the M&M study among others) that can't really be done with colas/juices; colors, textures, shapes ...

[0] just curious, has anyone come across foods engineered to be exothermic and/or endothermic ?

Susanne said...

You're right, I was thinking Kessler and the food hyper-engineered to slide down easy. I actually noticed that this week when I had a once-in-a-blue-moon McDonald's hamburger, it seemed to disappear in just a few bites compared to my normal home cooked meals, and was strangely unsatisfying as a meal even though I could tell my stomach was satisfied.

Found 2 review articles in a brief GoOgling on satiety and liquid calories, both with ambiguous results (there are earlier ones as Ivat notes that were stronger on the no-satiety effect):
2007: http://www.ajcn.org/content/85/3/651.full
2003; http://www.ncbi.nlm.nih.gov/pubmed/14649371

and here's a Rudd Center overview (pdf): http://www.yaleruddcenter.org/resources/upload/docs/what/policy/SSBtaxes/SSBStudies_Satiety.pdf

Are Pop Rocks endothermic as they go off? My chemistry classes are too long ago. Then there are the mint LifeSavers which are, I believe, piso-electric. But that effect is incidental, not engineered as far as I know.

OnePointFive said...

An Aussie blogger with a similar message
"Robert Lustig is an enigma. He is a credible scientist, a Professor of Clinical Pediatrics, an expert in neuroendocrinology and has published over 90 scientific papers. He rightly criticises the health authorities who advocated the low fat diet on the promise that it would cure society’s dietary ills, but has embarked on a similar single-nutrient crusade, this time targeting fructose. He uses sensationalist language and suggests that there are simple solutions to complex health problems. Surely the lesson of the low fat diet debacle was not to focus on one nutrient or dietary component, especially in relation to the prevention of weight gain where the emphasis needs to be on limiting calorie intake"
http://scepticalnutritionist.com.au/?p=95

Galina L. said...

Sometimes I think that Lustig diet advice and probably presentation style resulted from his work with obese children.

cliff said...

In my experience I eat less when I replace solid food with liquid calories but when you combine the two it is much easier to eat more calories.

Sanjeev said...

> Pop Rocks endothermic as they go off?

Thanks, you helped clarify my question. Pop rocks may have been slightly exothermic, yes.

In fact the safest, easiest way to design an endo/exo thermic effect into food is using chemicals that fool other senses. Menthol and capsaisin do that.

> that effect is incidental, not engineered
I count choosing materials that have a desired property/effect as engineering the effect into the product.

ProudDaddy said...

That makes it n=2.

Simon Carter said...

Cliff or PD, just curious, what liquid calories did you use to replace solid food?

cliff said...

Milk, OJ, sometimes soda

ProudDaddy said...

Whey protein shakes.

When I tried the 600 calorie diabetes cure diet, I found that high protein shakes had a higher satiety than the same calories from lean meat.

Please do not try this at home! (Other than a few days a month.)

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