Examining the Health Effects of Fructose

JAMA ^ | June 3, 2013 | David S. Ludwig, MD, PhD

[aruanan]

Yes, this is true. Is a diet of only protein and fat as healthy as one that includes carobohydrates?

Your body has an indispensable need for glucose/fructose for DNA synthesis and repair and for brain metabolism. If you have no carbohydrates whatsoever in your diet, you can use certain amino acids and other products of the catabolism of fats and proteins to produce glucose through gluconeogenesis.

[Huskrrrr]

Yes, I know most of the metabolic pathways and how they work, I teach biochemistry in college. My question is what are the long term health effects of a no carb diet (eg heart disease). There seems to be a disagreement among researchers as to the health consequences of a no carb diet. I was wondering what your opinion was on this subject.

[BobL]

“Besides that, real cane sugar in that amount actually seems to be a plus for digestion and feeling full and satisfied from foods.”

Yep, I think there’s something to that...I’ll try it too.

[Fractal Trader]

Eating it as a solid, bound up in fiber, as in fruit, results in an extended period of moderate levels of fructose entering the system.

I don't think anyone has suggested that fruit juice, for example, is as dangerous as HFCS soda, and I have never heard that carbonation, per se, is deleterious to your health.

[jdege]

I don't think anyone has suggested that fruit juice, for example, is as dangerous as HFCS soda

Actually, quite a few people have suggested that:

http://articles.mercola.com/sites/articles/archive/2010/06/19/richard-johnson-interview-may-18-2010.aspx

http://drjulindalee.wordpress.com/2013/05/13/what-fruit-juices-fructose-and-low-glycemic-index-really-mean/

[csmusaret]

I have no idea what the long term effects are, but for me my cholesterol improved quite a bit as a result of a 45 day no carb regimen.

[jdege]

There seems to be a disagreement among researchers as to the health consequences of a no carb diet.

Prolonged Meat Diets with a Study of Kidney Function and Ketosis

[Fractal Trader]

Interesting. I have been following a blog for the past two years which I have found authoritative on a wide variety of nutrition/obesity subjects, and he has never mentioned fruit juice to date, even though he has covered a wide variety of topics.

An interesting related subject is “de novo lipogenesis,” or the idea that sugar is turned into fat. Lots of research papers suggest that this is impossible, or quite uncommon.

Any way, here’s the link to his blog:

http://wholehealthsource.blogspot.com/

[napscoordinator]

without my fruit and protein I would keel over.

Stop eating it then....PLEASE!

[RipSawyer]

I had a doctor tell me that I could safely eat cantaloupe but not watermelon because supposedly the watermelon had a much higher fructose content. Having grown up hauling both of them to the market by the pickup load I had an idea he was wrong. A little research confirmed my suspicions, the sugar content varies more between varieties than it does between the average of the two categories, some varieties of cantaloupe have MORE sugar than some watermelons.

[Huskrrrr]

Thanks!

[Huskrrrr]

Thanks!

[jdege]

Lots of research papers suggest that this is impossible, or quite uncommon.

I'm unaware of any research papers that suggest that de novo lipogenesis is impossible, or that it is uncommon. Quite the contrary. The metabolic pathways exist in every animal species, from bacteria on up. The only question is the rate at which it happens, and whether it is a significant source of fat deposition.

On this, studies are mixed, at least with respect to glucose. There have been a number of studies that suggested that de novo lipogenesis is not a major pathway for most people. Which may be true.

The more important question, in my mind, is whether it becomes a major pathway for those with metabolic syndrome. And they suggest that for that population, DNL is a significant source of fat:

http://ajcn.nutrition.org/content/77/1/43.full

Until recently, DNL was believed to be an insignificant pathway in humans who eat a Western, high-fat diet. In addition, very little was known about the effect of the often recommended alternative diet, which is a low-fat, high-carbohydrate diet, on hepatic metabolism. However, with the development of new methodologies for measuring hepatic DNL, it was shown that hepatic DNL varies greatly depending on the health of the subjects (12, 13, 15) and the types of diets they consume (4, 5, 7, 9–11, 18, 19). The present study sought to answer 3 questions. First, do hyperinsulinemic obese subjects fed a Western, high-fat diet have higher fractional hepatic DNL than do normoinsulinemic lean or obese subjects fed the same diet? Second, is hepatic DNL increased when simple carbohydrate represents 54% of a low-fat, high-carbohydrate diet? And third, what is the relation of increased hepatic DNL to VLDL-triacylglycerol concentrations?

[...]

With the high-fat, low-carbohydrate diet, DNL was minimal and did not differ significantly between the lean and obese subjects with normal fasting insulin concentrations. In contrast, hyperinsulinemic obese subjects had a significantly higher DNL compared with both lean and obese normoinsulinemic subjects (Figure 1⇓; P < 0.05). Interestingly, although DNL did not differ significantly between the lean normoinsulinemic and the obese hyperinsulinemic subjects who consumed the low-fat, high-carbohydrate diet (Figure 1⇓), DNL was significantly higher (P < 0.05) with the low-fat, high-carbohydrate diet for both groups when compared with the normoinsulinemic subjects who consumed a high-fat, low-carbohydrate diet for 5 d (Figure 1⇓; P < 0.05).

(And one thing to note - this study's "low carb diet" was 45% of calories from carbs - which is anything but low carb the way the low carb community would define it. Atkins induction is less than 5% of calories from carbs, and I'd be willing to guess that at that level, DNL would be minimal even for those who were hyper-insulinemic.)

[poobear]

??? You being a prick or something?
How fat and unhealthy are you?
Can you ride 80 miles per week?
IOW screw yourself!