Knowledge and beliefs about dietary inorganic nitrate in a representative sample of adults from the United Kingdom

Abstract

Objective: Evaluate knowledge and beliefs about dietary nitrate among United Kingdom (UK)-based adults. Design: An online questionnaire was administered to evaluate knowledge/beliefs about dietary nitrate. Overall knowledge of dietary nitrate was quantified using a 21-point Nitrate Knowledge Index. Responses were compared between sociodemographic groups. Setting: UK. Participants: A nationally representative sample of three hundred adults. Results: Only 19% of participants had heard of dietary nitrate prior to completing the questionnaire. Most participants (~70%) were unsure about the effects of dietary nitrate on health parameters (e.g., blood pressure, cognitive function, cancer risk) or exercise performance. Most participants were unsure of the average population intake (78%) and acceptable daily intake (ADI) (83%) of nitrate. Knowledge of dietary sources of nitrate was generally low, with only ~30% of participants correctly identifying foods with higher/lower nitrate contents. Almost none of the participants had deliberately purchased, or avoided purchasing, a food based around its nitrate content. Nitrate Knowledge Index scores were generally low (median[IQR]: 5[8]), but were significantly higher in individuals who were currently employed vs. unemployed (median[IQR]: 5[7]vs.4[7]; p<0.001), in those with previous nutritional education vs. no nutritional education (median[IQR]: 6[7]vs.4[8]; p=0.012), and in individuals who had heard of nitrate prior to completing the questionnaire vs. those who had not (median [IQR]: 9[8]vs.4 [7]; p<0.001). Conclusions: This study demonstrates low knowledge around dietary nitrate in UK-based adults. Greater education around dietary nitrate may be valuable to help individuals make more informed decisions about their consumption of this compound.