Hypertension is the most common modifiable risk factor for cardiovascular disease (CVD) and contributes to more than nine million deaths annually.(1,2) Favourable secular trends in population blood pressure (BP) levels have been reported in many developed countries.(2) In Ireland, favourable trends in population BP levels have contributed to 28% reduction in coronary heart disease deaths over the past two decades.(3) In a modelling study, we have demonstrated that improving specific food choices (including reducing dietary salt intakes) would lead to further reductions in annual CVD deaths.(4) However, there are methodological challenges directly linking reductions in population dietary salt intakes to observed improvements in CVD outcomes.(5) Therefore, our study hypothesis is that a favourable secular trend in population BP levels is positively associated with an improvement in population dietary quality that captures dietary salt intake.