No longer beeting around the bush: a review of potential sex differences with dietary nitrate supplementation 1.

Over the last decade there has been substantial interest in the health and athletic performance benefits associated with acute and chronic dietary nitrate (NO3-) supplementation. Dietary NO3-, commonly found in leafy green and root vegetables, undergoes sequential reduction to nitrite and nitric oxide (NO) via the enterosalivary circulation. Importantly, NO has been shown to elicit a number of biological effects ranging from blood pressure reduction to improved exercise economy and athletic performance. However, a common absence within biological research is the lack of female participants, which is often attributed to the added complexity of hormonal fluctuations throughout the menstrual cycle. Despite mounting evidence supporting significant anthropometric, metabolic, and physiological differences between the sexes, this problem extends to the field of dietary NO3- supplementation where women are underrepresented as research participants. This review examines the existing dietary NO3- supplementation research with regards to dietary NO3- pharmacokinetics, resting blood pressure, exercise economy and performance, and mechanisms of action. It also provides evidence and rationale for potential sex differences in response to dietary NO3- supplementation and future directions for this field of research. Novelty Dietary NO3- supplementation has been shown to have positive impacts on health and athletic performance in generally male populations. However, women are underrepresented in dietary NO3- supplementation research. The present evidence suggests that sex differences exist in response to dietary NO3- supplementation and this review highlights avenues for future research.