Death from cardiovascular disease
High blood pressure is a risk factor for mortality at an earlier age. It is directly related to cardiovascular disease including stroke, heart attack and heart failure, which together are the leading causes of death and disability in the world. From clinical and experimental studies it is known that high salt intakes can be associated with left ventricular hypertrophy, albuminuria, renal hypertrophy and renal fibrosis, independently of each other. Some examples of studies carried out and their findings are as follows:
- A prospective study in Japan (Nagata et al., 2004) showed that death from ischaemic stroke or intracerebral haemorrhage was strongly associated with the individual's salt intake at the start of the study.
- A retrospective study in Finland (Tuomilehto et al., 2001) showed that salt intake, assessed from 24-hour urine collection was positively related to the frequency and death rate from coronary artery disease.
It has been estimated that the benefit of reducing salt intake by 3 g per day would be a 22% reduction in the prevalence of stroke worldwide and in the UK a reduction to the current WHO daily salt intake target of 5 g would prevent about 15 000 stroke deaths a year (O'Shaughnessy and Karet, 2006). In the case of myocardial infarction, there would be a 16% reduction in prevalence with a 3 g per day reduction in salt intake worldwide, and in the UK 30 000 deaths would be prevented if people limited themselves to a daily intake of 5-6 g.