Knowledge of inorganic nitrate dietary survey-2 (KINDS-2): a multinational cross-sectional study of nitrate knowledge, beliefs and purchasing behaviours in the general population and healthcare professionals

Dietary inorganic nitrate has cardioprotective and ergogenic effects, yet public and professional knowledge remains poorly characterised. In the KINDS-2 multinational cross-sectional survey, we assessed knowledge, beliefs and purchasing behaviours in a general population cohort (UK, USA, Australia; n = 2,970, recruited via Prolific) and a healthcare professional (HCP) cohort (42 countries; n = 498, recruited via professional networks). Knowledge was scored using cohort-specific indices and a harmonised cross-cohort comparable index (CCC-NKI; 20 points, seven domains). Knowledge was low in both cohorts: general population median 8.9/21, with only 28.7% having heard of dietary nitrate (USA 36.4%, UK 15.0%, Australia 11.2%); HCPs median 11.5/23. On the CCC-NKI, HCPs scores were higher in the general population (median 10 vs. 8; p < 0.001). Identifying nitrate-rich foods was the strongest correlate of total score yet showed no between-cohort difference. Most participants were willing to consume nitrate-rich foods given supporting evidence. These findings underscore the need for targeted education.