 Several small randomized trials have demonstrated benefits for cocoa flavanols on intermediate outcomes, including blood pressure, lipids, insulin sensitivity, and flow-mediated vasodilation. For multivitamins, a prior large-scale randomized trial in middle-aged and older men showed a significant reduction in cancer, but comparable trial data in women are lacking. For both interventions, a large-scale clinical trial such as COSMOS could have major clinical and public health implications. 