Oct 12 2009
It’s tempting to think that the practice of medicine should be simple and intuitive. Unlike other sciences, we all have access to the basic materials—ourselves. We feel that because we are intimately familiar with our bodies, we know a lot about how they work. Unfortunately, it’s a little more complicated than that. The biochemical processes walking around in this sack of meat are pretty complicated. Learning these processes is important, but in medicine, it’s not enough. If we have a hypothesis that some change in biochemistry will affect some disease, we must test this in groups of real people in well-designed clinical trials. Or, we can use the Huffington Post method and just make it all up.
The latest abomination is an article on diabetes, by Kathy Freston. Bad information on diabetes is particularly dangerous. The longer diabetes goes untreated, the higher the likelihood of complications. When reading medical writing it’s important to evaluate the source. The author of this article wrote a book called, The Quantum Wellness Cleanse which pretty much says it all. But is it really fair to judge someone on a crappy book title?
Well, yes, but more important is the crappy interview she conducts with Dr. Neal Barnard. I have no way of knowing with absolute certainty whether Barnard is as dangerous a fool as he sounds, but I suspect so. He and Freston promulgate a dangerously over-simplified view of diabetes.
To review briefly, type II diabetes is common and deadly. It affects around 20 million Americans and if poorly treated leads to stroke, kidney failure, heart attacks, amputations, and death. There is some evidence that in societies where people are poorly nourished or subsisting on minimal calories, diabetes is less common. The disease is highly heritable, and is not evenly distributed among ethnicities, with African Americans, Hispanics, many Native Americans, and probably South Asians being more affected than whites. The disease usually starts as resistance to insulin. Pancreatic beta cells bravely try to keep up, but eventually crap out. With early dietary intervention, diabetes can often (but not always) be controlled. Whether someone with diet-controlled diabetes is still a diabetic is not settled. There is more to diabetes than high blood sugar. We know that controlling blood sugar, cholesterol, and blood pressure in diabetics prevents devastating complications. If a diabetic loses 20 lbs and has normal sugars, we know we’ve reduced their risk, but evidence seems to support the idea that they are still “diabetic”, at least from the perspective of risk.
Some diets may be more or less “diabetogenic”, but in general, a combination of genes, increase caloric intake, and abdominal adiposity are the big baddies. Early in the course of developing diabetes, before the beta cells give up, it is usually possible to reduce insulin resistance by losing weight. There is no good evidence that one particular approach to eating can “cure” diabetes.
Getting back to HuffPo, Dr. Barnard makes the reasonable statement that our society’s increased caloric intake contributes to soaring diabetes rates, and talks about the complications of diabetes. He then goes on to fall for one of the most common types of pseudo-scientific thought—oversimplification:
Let me emphasize that this grim scenario does not have to occur. If an unhealthy diet is the cause, a better diet can provide the answer to this problem.
Well, yes, in many if not most type II diabetics, dietary changes and exercise can dramatically change the course of the disease—at least early on when the beta cells still work. But diet alone is not always sufficient to control diabetes, and it’s dangerous to imply that it is. From the rest of the interview, it’s apparent to me that Dr. Barnard either went to a different kind of medical school than I, or didn’t pay attention:
So long as your body’s insulin can escort glucose into the cells normally, diabetes will not occur.
That is a lovely fantasy, but not consistent with reality. He goes on to claim that fat intake is the cause of insulin resistance and that a vegan diet can prevent and reverse diabetes:
And we can go beyond prevention. When people who already have diabetes adopt a low-fat vegan diet, their condition often improves dramatically. In our research, funded by the U.S. Government, we found that a vegan diet is more effective than a traditional current diabetes diet, and is much safer than a low-carb diet.
The study to which he is presumably referring is interesting, but hardly groundbreaking. It compared a standard American Diabetes Association balanced diet with a vegan diet. Both groups did quite well, with the vegan group doing better by some measures. The study was randomized, but obviously not blinded, and patients developed their own diets with the help of dietitians. The diets were apparently not equally caloric and there was a large range of intake in both groups. Diabetic control measured by glycolated hemoglobin levels was not terribly impressive (p=0.091). By their own analysis, weight loss was more important than type of diet in determining improvement of diabetes.
While interesting, this is not a study on which to hang an entire medical philosophy. What troubles me about this article is that it creates/perpetuates a myth that diabetes (meaning type II diabetes) is always preventable and reversible with a particular diet. While I’m very happy to have my patients change their diets for the better, to tell them that a particular diet is some sort of panacea is just untrue. It is wrong. It is a lie. Diabetes is a serious disease, and anything that delays its proper treatment causes disability and death. Dietary changes are an important component in a comprehensive diabetic treatment plan, but the evidence is insufficient to recommend one diet over another.
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