Recent changes in salt use and stroke mortality in England and Wales. Any help for the salt-hypertension debate?

This analysis attempts to fill the gap in the epidemiological evidence about the relation between dietary salt and hypertension. Changes in the purchase of salt in England and Wales are compared with changes in mortality from cerebrovascular disease (1958-78). Stroke mortality, a major sequel of hypertension, has declined in this period. Consumer purchases of salt have decreased also, as suggested by the National Food Survey. While these trends are consistent with the salt-hypertension hypothesis, the picture is confused by an increase in meals eaten outside the home, by the consumption of more processed food, and by a higher prevalence of refrigerators. Other events, such as medical treatment of hypertension or changes in the case fatality rate, could have contributed to the decline in stroke mortality. This secular trend analysis, using available data, does not clarify the salt-hypertension debate.