using standardized methods for measuring 24-h urinary
sodium and BP. The intention was to study communities with a
wide range of salt intake, e.g. from 0.5 to 25 g/day. A total of
10 079 individuals from 52 centres around the world were
recruited into the study. However, among these 52 communities,
only 4 had a low salt intake (i.e. ≤3 g/day) and the majority lay
between 6 and 12 g/day and none had the high salt intake as originally
envisaged. Nevertheless, the study demonstrated a significant
positive relationship between salt intake and BP. There was also a
highly significant positive relationship between salt intake and the
increase in BP with age (Figure 1). It was estimated that an increase
of 6 g/day in salt intake over 30 years would lead to an increase in
systolic BP by 9 mmHg