Feb 16, 2004

i go nuts for donuts

Here's an interesting website - Second Opinions. I've done a fair amount of reading in the area of general health and I must admit I've done my fair share of diets. Although I will preface that by saying I was making a lifestyle change rather than participating in a short-lived diet. But over time I've spent a little more time trying to understand the data behind some of these health theories. And it all finally came to a head in my mind after reading a book called The Cholesterol Myths. I finally realized that for whatever reason the governmental institutions and researchers that are supposed to promote health have basically been feeding us falsehoods - actively or inactively I'm not sure. This ranges from the lack of evidence linking heart disease to cholesterol, to the lack of evidence linking obesity to fat intake, to the fact that nutrasweet (aspartame) should never have been FDA approved, to that fact that a high carbohydrate diet seems to cause diabetes. It just seemed to go on and on as I dug into the facts.

Having been a scientist I understand how this can happen. In fact the linked site has a great quote that sums up how this kind of thing can happen.
The tragedy of science is the slaying of a beautiful hypothesis by an ugly fact.
attributed to T. H. Huxley. The pressure to change experimental data to suit the hypothesis you have going into an experiment is difficult to overcome. Trust me it is hard. The reason I like this site is it does a good job of laying out some of the more basic facts around these theories with a really critical eye towards the research. I'll give you one example I've come across but is not on this site. A low-carb diet is linked to kidney failure/kidney disease/kidney stones. This is a very common comment people make to you if you tell them you are on a low-carb diet. Here's the basics of the study. Let me point out a few things here.

  • This is the primary study people and articles are referring to when they link low-carb diets to kidney issues. Go on. Do a google search to see if you come up with anything else that supports this hypothesis. Most references are to this study in particular.

  • 1st blatant problem - Nowhere does this study claim anything about kidney failure or disease, only kidney stones. This in itself is interesting because secondary reports on this study vary what it is they are trying to show.

  • 2nd blatant problem - 10 healthy subjects were chosen. 10!? And I'm supposed to believe any data you show me. Try 30 at an absolute minimum to get anything statistically worthwhile. I have no idea why they even bothered doing this study and why on earth a peer reviewed journal would sanction the work. To be fair I don't know if it appeared in a peer reviewed journal but then journalists should not be quoting the study.

  • 3rd blatant problem - The co-author of the study shows he went in with a hypothesis that low-carb diets cause kidney problems by his statement that low-carb diets lead to a state called ketoacidosis which is bad. This is a horrible misrepresentation of the literature. Diabetic Ketoacidosis is a state of insulin deficiency aggravated by hyperglycemia, dehydration and acidosis derangements in metabolism. The most common cause is an infection or the onset of diabetes. And it is indeed bad. The presence of ketones in the bloodstream is a symptom of having the condition. Just because you have ketones in your body does not mean you have ketoacidosis nor does it mean ketones in your blood is bad. Maybe it does but there is no proof.

  • More of the 3rd blatant problem - The co-author also goes on to state that "our bodies need a certain source of energy and a quick source are carbohydrates". Well sure carbohydrates are a source of energy but so is vodka. So what? But where does he get this 'our bodies need a certain form of energy' from? There are no studies that show this. It is bias. He's suggesting our bodies need carbohydrates. But there are no 'essential carbohydrates'. There are essential oils. There are essential proteins. There is no such thing as an essential carbohydrate. In fact if your body needed carbohydrates, and your brain does, your body can produce them. And if you don't eat any carbohydrates that's exactly what your body does.

  • 4th blatant problem - No one got kidney stones. The study was for 8 weeks; 6 weeks of which were on a low carbohydrate diet. So how do they determine the risk went up? They state that acid excretion increased up to 90% and urinary citrate fell by 25%. So what? Well this is supposedly a marker for kidney stones. Oh it is? Go to another google search. First, citrate levels and acid excretion levels need to be significantly lower and higher respectively to fit under the parameters of previous studies. Which means it is only the trend that is leading the researchers to think this is a problem. Second, and more importantly, these previous studies are correlative. There is no causal mechanism discussed. In fact more most of the studies are related to people who have another condition called hypocitraturia or low levels of citrates. Maybe the source of the condition is causing kidney stones? Who knows. All I know is they haven't shown anything. In fact other studies list the correlation of other factors that relate more closely to kidney stones. In order of importance - calcium intake, sucrose intake, sodium intake, fluid intake, and potassium intake. What is sugar doing on there?

  • 5th blatant problem - Six weeks does not seem like enough time to allow the body to go into an equilibrium state. It's well known that a low-carb diet causes larger rates of water discharge initially. Could this cause the increased measurements of citrate discharge?

  • 6th blatant problem - And probably the worst. There is no control group. Why is this bad? First there's no way of understanding what 6 weeks of regular diet will produce on a subject. Second, the study is not blind and certainly not double blind. The people who did the actual blood work knew all of the candidates were on the low carb diet. And as I said before if your hypothesis going in is that it causes problems then you are going to monkey with the data. If you don't and the data shows nothing happens then you really don't have an interesting study to publish on your hands. Negative studies, studies that show something did not happen, are not viewed in the same way as studies that show something does happen. It's a tragedy of science that this is true but that is how it is.

  • 7th blatant problem - A challenge was put out to produce one person who developed kidney disease as a result of the low carb diet. No one has produced any.

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