The first thing the reporter asked me in the telephone interview was “why is the American Diabetes Association (ADA) opposed to low carbohydrate diets?” I said I didn’t really know. I admitted that they had allowed themselves certain indulgences but I pointed out that they are trying to back into low carbohydrate diets however weakly. In any case, the ADA is many people and I doubted that the rank and file members of the ADA even know what the nutritional committee has to say. So, although the ADA represents, in some way, the establishment position, nobody really knows what practicing physicians and clinics actually do.
Carbohydrate restriction in the management of diabetes
Out of love and concern for the truth, and with the object of eliciting it, I have laid out the basic principles behind carbohydrate restriction as the “default diet” (the one to try first) in the treatment of diabetes. Dietary carbohydrate restriction derives from fundamental biochemistry and has been a traditional therapy for diabetes before and since the discovery of insulin. The strategy is based on the fundamental idea that diabetes is a disease of carbohydrate intolerance (inadequate or absent insulin in response to carbohydrate (type 1) or inability to respond to insulin accompanied by deteriorating pancreatic function (type 2). Control of blood glucose has positive effects on all of the downstream sequelae including lipid markers for and incidence of cardiovascular disease. No experimental or clinical data has shown any contradiction to these principles. The following 15 theses are the basis for re-evaluation of the role of carbohydrate restriction in treatment of type 2 diabetes and adjunct to treatment of type 1 diabetes.
The Fifteen Theses.
- Almost all of the increase in calories during the epidemic of diabetes is due to increased carbohydrate. Fat, if anything, went down. Consumption of most foods, including fruits and vegetables increased. The exceptions were red meat and eggs.
- Dietary carbohydrate restriction reduces insulin fluctuations and is the most effective approach to glycemic control, the primary targets of nutritional therapy.
- Adherence to low-carbohydrate diets is at least as good as other dietary interventions and frequently substantially better. Adherence is frequently comparable to that for drug recommendations. In practice, diabetes clinics and internet sites recommend carbohydrate counting and “eating to the meter.”
- No dietary intervention is better than carbohydrate-restriction for weight loss. Low-carbohydrate diets generally do better than low-fat diets for whatever period they are compared. Long term trials of low-fat diets such as the Women’s Health Initiative have a consistent record of poor performance.
- Contrary to stereotypes, low-carbohydrate dieters do not substantially increase either fat or protein consumption. Whereas per cent fat may increase, the absolute amount of fat does not change much before and after a carbohydrate-restricted diet. Low-carbohydrate diets are high in vegetables and, in practice, are not particularly iconoclastic. Such diets are relatively low in fruits but researchers emphasize that fruits and vegetables are nutritionally different: per gram, fruits have, on average, more calories, more carbohydrates, more sugar, fewer antioxidants and lower potassium.
- The best predictor of microvascular and, to a lesser extent, macrovascular complications is hemoglobin A1C which is substantially under the control of chronic dietary carbohydrate restriction.
- Although carbohydrate-restricted diets do not require the addition of saturated fat, numerous studies have shown that, contrary to popular opinion, dietary total and saturated fat are not associated with incidence of cardiovascular disease (CVD).
- Dietary carbohydrate restriction is the single most effective method (except for total starvation) of reducing triglycerides, and is as effective as any intervention, including most drugs, at increasing HDL and reducing the number of small-dense LDL particles. Beyond lipid markers, carbohydrate restriction improves all of the features of metabolic syndrome.
- Intensive glucose lowering by dietary carbohydrate restriction has no side effects comparable to intensive pharmacologic treatment as, for example, in the ACCORD trial or other agents whose safety is continually challenged.
- Beneficial effects of carbohydrate restriction do not require weight loss. Under weight maintenance conditions, dietary carbohydrate restriction dramatically improves glycemic control, hemoglobin A1c and lipid markers.
- Patients on carbohydrate-restricted diets reduce and frequently eliminate medication whereas high-carbohydrate, low-fat diets may lead to increased use.
- Diets based on carbohydrate-restriction are, in fact, widely practiced clinically, if in an unsystematic way. Contrary to recommendations of government and private health agencies, individual practitioners and clinics frequently recommend dietary carbohydrate restriction.
- Even as establishment nutrition slowly accepts low-carbohydrate diets there is a consistent failure to recognize or cite the work of researchers in this field. This contentious “two worlds” approach has added to the confusion for patient and practitioner alike.
- A variety of sources — input to government hearings, popular books and internet forums — have documented a large population of patients who are significantly dissatisfied with current medical treatment and feel that they have not been offered a valuable treatment and, in fact, have been harmed by recommendations of their physicians and health agencies. Added to the patients who feel that low-fat recommendations have misled them on obesity, we have created a population of people who distrust all health recommendations. .
- The palpable opposition to carbohydrate restriction of granting agencies has narrowed the focus of basic research. Downstream insulin signaling, for example, is more likely to be funded if it does not mention that carbohydrate stimuli for insulin signaling.
The 15 theses above are my take on the problem, subject to anybody else’s input. I am not sure it would do much good to nail them to the door of the ADA, but they may be good arguing points for trying to move forward. My suggestions, as noted before, are to ask for:
- Open hearings on nutrition in which all credentialed researchers participate and, in particular, researchers in low carbohydrate diets meet with their critics (a kind of Diet of Worms).
- Funding of a comparative study in which researchers in carbohydrate restriction and experts in other diets cooperate in the design and analysis of outcomes. Possible results and their meaning are agreed upon in advance and finally,
- New oversight agencies (possibly from National Science Foundation or Office of Science and Technology Policy) where truly neutral scientists can evaluate information and make recommendations (or not if there is no evidence).