Clinical use of evidence-based medicine: studies used to assess harm

Studies of harm are often carried out in cohort or case-controlled studies. We reviewed a prospective cohort study by Halton et al that assessed increased cardiovascular events in women on a low carbohydrate diet. This study did not show an increase in cardiovascular events. However, the diet assessment was very subjective, and the control group was dissimilar. The fact that these women were not trying to lose weight may have also affected the results. The randomized controlled trial by Trudy et al compared weight loss in 4 different commercially available diets and revealed similar weight loss in all 4 groups. Cholesterol levels did not increase in the Atkins group and systolic blood pressure decreased, although not significantly. Our patient will likely lose weight if she is able to continue with any of these diets. Although the evidence evaluating increased cardiovascular events in patients on the Atkins diet is not strong, the available evidence does not show that the Atkins diet increases this risk.