soda canYou should lay off the sauce--it\'s not good for your liver. [Author's Note:] This post, reacting to the findings of a University of California, Davis, study on fructose, quoted and relied heavily on an error-laden Times of London story. That said, the post generated a lot of valuable discussion in the comments section below, including a critique of the Times piece by Dr. Kimber Stanhope, one of the authors of the Davis study.

In response to another comment, Dr. Stanhope agreed that the question remains how much fructose is safe to consume and she indicated that a current project of hers involves testing that question with HFCS itself.

As I said at the end of the piece, the fundamental issue is that we consume too much sugar in any form. However, total fructose consumption has also increased dramatically thanks to juices and, yes, HFCS. While the simple answer going forward is to consume less sugar period, looking backward, it seems to me that we will indeed discover that changes in consumption patterns in different type of sugar over the last thirty or so years played a significant role in the current obesity/diabetes epidemic.

Oh, and in case anyone from the Times of London is reading this, if you think I will ever link to or quote from one of your articles again, then you've been drinking too much of the Kool-Aid that your boss Rupert Murdoch hands out.

Last year, a set of studies came out suggesting that the problem with high-fructose corn syrup was simply that people consumed too much of it. There was, according to these studies, nothing unique to the chemistry of HFCS that suggested it played an oversized role in the current obesity epidemic (aside from HFCS's little mercury problem, of course). Even at the time, however, there was a tantalizing suggestion in the media coverage that maybe, just maybe there was still some special risk to consuming HFCS due its higher fructose concentration:

[T]he research appears to show that sucrose and high-fructose corn syrup are not that different, [Professor of clinical nutrition Elizabeth] Parks says. She believes there's some evidence that the way they are metabolized in the liver is different, but not in a way that makes the calories from high-fructose corn syrup more likely to be stored as fat.

Well, wouldn't you know it, some resourceful scientists in UC Davis recently decided to look into that. And here's what they found:

Scientists have proved for the first time that a cheap form of sugar used in thousands of food products and soft drinks can damage human metabolism and is fuelling the obesity crisis.
Fructose , a sweetener derived from corn, can cause dangerous growths of fat cells around vital organs and is able to trigger the early stages of diabetes and heart disease.
...Over 10 weeks, 16 volunteers on a strictly controlled diet, including high levels of fructose, produced new fat cells around their heart, liver and other digestive organs. They also showed signs of food-processing abnormalities linked to diabetes and heart disease. Another group of volunteers on the same diet, but with glucose sugar replacing fructose, did not have these problems.

Okay then. This could be big. The issue, by the way, isn't so much the difference in the amount of fat fructose consumption produces. It's what it does to our metabolism the way it's metabolized and where it puts the fat it creates goes that matters. And I don't use the word "our" lightly. Significantly, this is one of the first studies not to use what scientists refer to as an "animal model," aka rats -- this study was performed in humans.

And here's where the liver comes in [UPDATED: this section adjusted and erroneous information, along with the quote from the source article, removed based on the study author's comment below]-- unlike glucose, some of which passes through the liver and is then excreted, 100% of fructose that's consumed is taken up by the liver. This is turn leads to increased fat deposition in the abdominal cavity and increased blood levels of triglycerides -- both of which are risk factors for heart disease and diabetes.

To be clear, this is something other sugars don't do. It's a special feature of fructose. And once scientists started looking more closely at the metabolic changes process and the way the fat was distributed, they saw the damage fructose can do to the human body. Now, as Fooducate observes the study used 100% fructose to test this effect, not HFCS itself, which is 55% fructose. A common observation is that white sugar is 50% fructose and thus will cause some of this as well, so what's the difference? Well, that extra bit of fructose in HFCS [not to mention the other sources of fructose in our diets] may be all the difference we need over a lifetime of consumption to create serious health problems.

It's both tempting and misguided to search for a silver bullet for obesity epidemic and there's no question that reducing or removing added sugar from our diet is a necessary step. But a lingering coincidence remains that the obesity epidemic exploded around 1980 -- the same time that HFCS was introduced into our food system on a mass scale. And it's not hard to come up with a scenario where the introduction of HFCS changed not only the total amount of sugar that we consumed but also the percentage of that sugar that was fructose in a way that meaningfully affected our metabolisms. And that effect may have been large enough to push rates of diabetes and obesity to unsustainable levels. As a result, I do believe it's fair to say that the causal arrow for that marginal increase in serous health effects from obesity is starting to point in the direction of HFCS.

The industry, of course, will continue to obfuscate, as this UK group did in its immediate response to the new data:

Rejecting the California research, a spokesman for the Food and Drink Federation, a UK industry trade group, said: “It makes no sense to highlight one single ingredient as a cause of obesity.”

On the other hand, sometimes the shoe simply fits. I have no doubt that now that scientists know where to look, HFCS is in for some serious science-based trouble. Not that our government will bother to help us on this front, no matter how dangerous to our health HFCS may prove to be.

But how does it make you feel to know that not only is that bisphenol A-lined can of soda altering your hormones, it's changing the way your digestive and metabolic systems function, too! My advice: next time you're tempted to grab an HFCS-sweetened soda (which is to say pretty much any soda), just watch this.