Oh, man. What now? Of course, I had to figure out what was going on, and it turned out that the media was flooded with similar stories, with headlines such as "Atkins-style diets can clog up arteries", "Low-carb diets could increase heart attack risk", "Low-carb diets damage arteries", and "Health risk from low-carb diets". I also had several emails from concerned readers. Of course, it was important for me to understand the implications of this latest study.
One thing I've discovered since becoming a health writer is that oftentimes the media gets it wrong in their reporting of research, and this was no exception. Reading the study for myself, I found out the following:
- The subjects in the study were genetically-altered mice. It turns out regular mice don't get clogged arteries, so they have to use genetically-altered ones. One question I have is "genetically-altered to get clogged arteries in response to what"? I do not know the answer to this.
- The low-carb group was eating an amount of protein far above that recommended in any low-carb diet book you will find: 45%. The head researcher, Sin Yin Foo, has been quoted as saying that "We had a diet specially made that would mimic a typical low-carb diet." Where did he get the idea that this is typical? Not likely from any of the popular low-carb diet books such as Atkins, Protein Power, South Beach, etc. In general, protein recommendations for low-carb diets are well within the recommendations of the Institute of Medicine, which set a maximum of 35% of calories from protein (and most people don't get nearly that high, as for most people a diet which gets a third of its calories from protein is simply unpalatable -- in other words, kind of gross). Dr. Foo probably got his information by listening to the prevalent myths about low-carb eating -- too bad he wasn't a little more careful.
- In any case, the mice did not react the same way humans do to low-carb diets. How do I know this? Because of a chart which showed that of the three diet groups, the mice on the low-carb diet had by far the highest triglycerides. This is the opposite of how almost all humans react. Lowered triglycerides has been called "a hallmark of the low-carbohydrate diet", with some physicians even using triglyceride levels to tell if their patients are sticking with their diets. So if the mice didn't respond typically to a low-carb diet in this way, how else did their response differ from humans? We just don't know.
- As they grew, the low-carb group naturally ate less, and gained 28% less weight than the other mice.
- In their literature review, as far as I can tell, the many studies showing benefits from low-carb eating were totally ignored.
The Bottom LineBased on the results of this study, I advise the following:
- Wait for human studies before taking this seriously. The scientific literature is full of animal studies that turned out to be irrelevant in humans. Rest assured there is a strong scientific basis for carbohydrate restriction for people.
- Avoid eating more than the recommended 35% protein in your diet (don't worry, it's doubtful you are doing this unless you are trying to eat a diet which is low in both carbs and fat -- not generally a good idea).
- Under no circumstances should you consume High-Protein Mouse Chow as your primary food (though a little nibble now and then is not likely to hurt you).
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