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Comment by Uhhrrr | Hacker News Reader

Two comments from the article that I liked:

As the principal author of this study, I wanted to clarify some of its details for scientifically-minded readers, in order to avoid misinterpretations: http://epianalysis.wordpress.com/2013/02/27/sugardiabetes/

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The opening line ("Sugar is indeed toxic.") is distorted and inane. Sugars are not toxic, as evidenced by our evolution of taste buds that respond so positively to them. Sugars are a dense source of energy, which is why our metabolic systems cherish them. Let's leave such excessive, unsubstantiated commentary to The Onion or Mad Magazine, and just apply common sense to our diets.

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Dr. Lustig does indeed claim sugar is toxic in the same since that alcohol is toxic. He goes through the complete cycle of metabolizing 1 molecule of sucrose (1 half glucose linked to 1 half fructose). The fructose metabolism is the problematic part, which was hard to follow for me, and I have an undergrad degree in Biochemistry and graduated with a 4.0. Here is the original talk: http://www.youtube.com/watch?v=dBnniua6-oM

JPKab below has a good high level overview.

Toxicologists are far more likely to emphasize dosage, eschewing the categorisation of chemicals as toxic or non-toxic . Non-toxicologists “tend to view chemicals as either safe or dangerous and they appear to equate even small exposures to toxic or carcinogenic chemicals with almost certain harm" [1].

[1] http://onlinelibrary.wiley.com/doi/10.1111/j.1539-6924.1992.... Intuitive Toxicology: Expert and Lay Judgments of Chemical Risks (2006)

It's a problem of translation between the chemistry definition of toxic (it will kill you in short order) and the common definition (poisonous, noxious). Bittman was using the latter, with an understanding that the dose makes the poison.

I don't think either of those definitions are well served by evidence.

And which sugars too? Most of us would assume this means glucose, but what if fructose is also a factor? Could fruit cause diabetes? Or perhaps the galactose in milk? Sugar alcohols?

It doesn't even mean glucose. Glucose is, as best we can tell, just fine. Which is almost a given, considering "blood sugar"- a key way your body distributes energy to your cells- is glucose.

Most studies that conclude "sugar" is "toxic" are talking about fructose, which is metabolized differently than glucose. This means fructose (e.g. HFCS) and sucrose (table sugar, e.g. cane sugar)

Glucose is, as best we can tell, just fine.

Obviously glucose is fine at some level -- as you say, the body uses it internally.

But that doesn't mean that there wouldn't still be a problem if we only got rid of the fructose we're eating and replaced it with glucose. The quantity of glucose we would then be ingesting with each meal would be quite large, and that might have other negative consequences -- mediated, perhaps, by the even larger insulin release that would be triggered.

But I'm only speculating. I haven't come across any research that bears on this question. If you have, I'd like to see it.

Does it also include fructose, the main sugar in apples, oranges, bananas, berries, tomatoes, and corn?

If I remember the oChem correctly, HFCS is just glucose and fructose mixed.

Yes, that fructose.

You are correct. HFCS is unassociated glucose and fructose, and to my understanding is pretty much interchangeable with sucrose, as sucrose is enzymatically cloven almost immediately.

I will throw in that firstly, it is theorized that the fiber in apples etc provides some regulation to the absorption of the fructose and that somehow changes matters. Secondly, and in my mind more importantly, it is much easier to gorge on pure sugar than it is to eat an equivalent amount of sugar in the form of apples.

I'd also point out that there's no way in hell we evolved a metabolism that expected ready access to as much fruit as we could eat for 12 months of the year.

Why is that? In nature, different fruits ripen at different times. Even if you were restricted to nature's cycle, there could potentially be fruit available for most of the year.

http://www.cuesa.org/page/seasonality-chart-fruit-and-nuts

I mean, sure, you wouldn't have access to all of these fruits in one location, but point being fruit wasn't something you got for a week in June, then never again until next June.

Important to note that this is the opinion section, not news. I wonder how many people are going to miss that detail?

As with sugar, most toxins are only toxic at a certain level of intake.

If you are talking about toxicity, this is a useless observation. Everything is toxic at certain levels. Did you know that there is an LD50 for water?

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