The article's writer is Gary Taubes who has previously written a book called Good Calories, Bad Calories that's actually nearly a decade old now. That will be next on my reading list, but from what I'm told, it is extremely well researched and uses quite a bit of common sense. Something that is often lacking when it comes to nutritional science. The theory itself is well over thirty years old, but was long ago dismissed by many nutrition "experts" as being incorrect. That is slowly changing now.
The theory basically states that table sugar (sucrose) is bad for you. That seems obvious until you delve into precisely what is meant by this claim. It is not just that it provides "empty calories" and little nutritional value, but that it actually causes damage to your body. Obesity is the most obvious health threat (and probably the one people care most about), but the implications suggested by its metabolic pathways and the byproducts are actually far greater. It has been proposed that sugar may be responsible for a lot of the chronic disease that seem to be epidemic in first world countries, and most especially in the USA. Many of these diseases have inflammatory components with unknown etiologies. Experts often concluded they were simply the result of genetics and some unknown environmental component. If this theory implicating sugar (specifically fructose) turns out to be correct, the implications are mind-boggling, both on a public health and economic level.
The NY Times article revolves around a popular YouTube video of a lecture given by UCSF pediatric endocrinologist, Dr. Robert Lustig. Since being uploaded, the video has received a little over 1 million hits, which is quite remarkable considering it is a 1 1/2 hour medical lecture.
Dr. Lustig himself is a bit of a controversial figure in that he takes a hard stance on sugar and flat out calls it a "toxin". Which is technically true if his theory is correct in that it causes damage to your body. However, much of the lay public will refute that claim because people tend to think of toxins as substances that will make you drop dead very rapidly after you ingest it. But in the lecture he describes it as a chronic toxin - fair enough. One could argue that things like lead, ethanol, and tobacco are also chronic toxins, and there would be far less controversy. But only because those substances are already accepted as being bad for you. Human nature being what it is, we tend to resist ideas that change our fundamental understanding of things. Sugar causing diseases is not a widely accepted idea and understandably faces much resistance. Judging from some of the discussions online, some even consider it heresy.
Here's the basic idea of the theory: sucrose is 50% glucose, 50% fructose. Glucose is fine and good. In fact most of the energy metabolic pathways in your body have the ultimate goal of producing or storing glucose. This means starchy foods like rice, potatoes, and pasta get a pass. Fructose has a very similar chemical structure. However, it is metabolized very differently from glucose and this is where the bad stuff happens. It not only gets converted to fat, it wrecks havoc on your satiety hormones, and leads to production of an inflammatory substrate that causes damage to the lining of your blood vessels (among others consequences). The health implications are staggering. FAR more so than the fat and cholesterol we consume, it contributes to heart disease and may very well be the single largest factor. The epidemiological evidence supports the biochemical implications - the rise in heart disease in the USA correlates very well with the rise in average daily consumption of sugar, which all began when our well-intentioned nutrition experts waged a war on dietary fat in the 70's and 80's. We are now still paying for the repercussions.
What about fruit? Good question. Many people excuse fructose because it's found "naturally" in fruits, which sounds reasonable at first glance. But in nature, fructose (or sucrose) is almost always found with equal or much more amounts of fiber, such that A) it's difficult to consume a large quantity without getting full from fiber and B) fiber slows down the absorption of whatever fructose is there. There's nothing natural about fruit juice or crystallized sugar (even "unprocessed" raw sugar). When we drink down a glass of orange juice (or other fruit juice), we are not only ingesting a much greater quantity of fructose, but removing fiber which would've slowed its absorption. And that leads to an interesting thought: what if fructose is nature's way of getting us to eat fiber and the other nutrients in fruit that we wouldn't otherwise eat? Here's another thought: because of farming and mass shipping, we are capable of eating fruit 24/7 365 days a year. This is what our nutrition experts propose with our silly food pyramid. What if we weren't supposed to eat it all the time? Unless you live in the tropics, you would naturally only have access to fruit several months out of the year and even then in limited quantity. So this raises an interesting question, is it truly healthy to eat fruit every day?
If you get the chance, read the article and watch the video. The video is 1 1/2 hours long and Dr. Lustig can be a little annoyingly smug at times. However, his ego not withstanding, it's an interesting lecture and the evidence he presents is very compelling. It makes complete sense biochemically and epidemiologically. To be fair, Dr. Lustig didn't come up with this theory. It's at least thirty years old, but because of politics and and economic forces, it was dismissed by nutrition policy makers and conventional wisdom held that it was generally a harmless food item and that fat/cholesterol was the real danger - a true public health disaster. I'll post my thoughts on the details in followups, but suffice it to say, I'm sold on this theory.
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