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The inability of current recommendations to control the epidemic of diabetes, the specific failure of the prevailing low-fat diets to improve obesity, cardiovascular risk, or general health and the persistent reports of some serious side effects of commonly prescribed diabetic medications, in combination with the continued success of low-carbohydrate diets in the treatment of diabetes and metabolic syndrome without significant side effects, point to the need for a reappraisal of dietary guidelines. The benefits of carbohydrate restriction in diabetes are immediate and well documented. Concerns about the efficacy and safety are long term and conjectural rather than data driven. Dietary carbohydrate restriction reliably reduces high blood glucose, does not require weight loss (although is still best for weight loss), and leads to the reduction or elimination of medication. It has never shown side effects comparable with those seen in many drugs. Here we present 12 points of evidence supporting the use of low-carbohydrate diets as the first approach to treating type 2 diabetes and as the most effective adjunct to pharmacology in type 1. They represent the best-documented, least controversial results. The insistence on long-term randomized controlled trials as the only kind of data that will be accepted is without precedent in science. The seriousness of diabetes requires that we evaluate all of the evidence that is available. The 12 points are sufficiently compelling that we feel that the burden of proof rests with those who are opposed.

Despite extensive study, there is little experimental information available as to which of the deoxyribose hydrogen atoms of duplex DNA reacts most with the hydroxyl radical. To investigate this question, we prepared a set of double-stranded DNA molecules in which deuterium had been incorporated specifically at each position in the deoxyribose of one of the four nucleotides. We then measured deuterium kinetic isotope effects on the rate of cleavage of DNA by the hydroxyl radical. These experiments demonstrate that the hydroxyl radical reacts with the various hydrogen atoms of the deoxyribose in the order 5 H > 4 H > 3 H Ϸ 2 H Ϸ 1 H. This order of reactivity parallels the exposure to solvent of the deoxyribose hydrogens. Our work therefore reveals the structural basis of the reaction of the hydroxyl radical with DNA. These results also provide information on the mechanism of DNA damage caused by ionizing radiation as well as atomic-level detail for the interpretation of hydroxyl radical footprints of DNA-protein complexes and chemical probe experiments on the structure of RNA and DNA in solution.The hydroxyl radical (⅐OH), the quintessential reactive oxygen species, is the mediator of much of the DNA damage caused by ionizing radiation (1). This damage includes strand breaks, which are initiated by abstraction of a deoxyribose hydrogen atom by the hydroxyl radical. DNA strand breaks induced by the hydroxyl radical also form the basis of a widely used method for making footprints of DNA-protein complexes (2, 3) and for studying the structure of DNA (4) and RNA (5) in solution. The key experimental advantage of the hydroxyl radical as a chemical probe is that it effects DNA cleavage with no base-or sequence-specificity (6-8). The hydroxyl radical produces highly detailed footprints that yield information about DNA structure (4, 7) and protein-DNA interactions (3, 8, 9) at single-nucleotide resolution.Mechanistic information on the reaction of the hydroxyl radical with nucleic acids will benefit our understanding of radiation damage to DNA as well as the interpretation of chemical probe experiments. The extensive literature on the radiation chemistry of DNA (1) is a rich source of mechanistic possibilities. Not surprisingly, because of the high reactivity of the hydroxyl radical, a wide spectrum of products has been detected on treatment of the constituents of DNA (nucleic bases, nucleosides, nucleotides, or simple-sequence singlestranded DNA, for example) with ionizing radiation (1). It has been more difficult to conduct similarly detailed experiments on the biologically relevant duplex form of DNA. It is not hard to conceive, though, that the hydroxyl radical might react in a different manner with double-stranded DNA compared with simpler nucleic acid systems because the shape of the double helix would strongly influence the accessibility of the various COH bonds in DNA.Until now, the extent of cleavage at a particular nucleotide in a hydroxyl radical footprinting experiment only could be interpreted at th...

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