medwireNews: Countries should aim for even lower adult salt consumption than the current World Health Organization (WHO) targets, say researchers.
Two reviews published in the BMJ show that reduced salt consumption results in dose-dependent reductions in blood pressure, while a further review supports increased potassium consumption in patients with high blood pressure to reduce the risk for stroke.
The authors of one study say that the target daily salt consumption for adults should be 3 g per person, lower than the WHO's goal to reduce global adult consumption to 5-6 g/day by 2025.
"The current recommendations to reduce salt intake from 9-12 to 5-6 g/day will have a major effect on blood pressure, but a further reduction to 3 g/day will have a greater effect and should become the long term target for population salt intake," say Feng He (Queen Mary, University of London, UK) and colleagues.
Meta-analysis findings informed new WHO guidelines issued in January which for the first time made recommendations on potassium intake levels.
The reports also allay recently raised concerns that changes to salt and potassium consumption can result in biochemical disturbances, finding no evidence for adverse effects on blood lipids, hormone levels, or kidney function.
He and colleagues analyzed 34 trials including 3230 participants that reported the effect of modest declines in salt intake (mean 4.4 g/day). They observed a mean -4.18 mmHg change in systolic blood pressure and a mean -2.06 mmHg change in diastolic blood pressure. The effect was most pronounced in patients with hypertension but still led to significant declines in blood pressure in normotensive individuals.
Nancy Aburto (WHO, Geneva, Switzerland) and colleagues reached similar conclusions in their analysis of sodium consumption reported by 56 studies. As well as finding significantly lower blood pressure among participants who consumed lower amounts of sodium per day, they observed no adverse effects in terms of blood lipids, catecholamine levels, or renal function. They also report that increased sodium intake was associated with a 24% increase in the risk for stroke, a 64% increase in the risk for stroke mortality, and a 32% increase in the risk for coronary heart disease mortality.
Meanwhile, in a separate analysis of 33 studies involving 128,644 participants, Aburto and colleagues found that increased potassium intake resulted in a significant reduction in systolic and diastolic blood pressure (average 5.93 and 3.78 mmHg, respectively), with the greatest reductions observed in those who increased their potassium consumption by 90-120 mmol/day. On the basis of this evidence, WHO now recommends that adults and children should increase their potassium intake from food and that adults should consume more than 90 mmol/day for beneficial effects on blood pressure and risk for related cardiovascular disease.
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By Kirsty Oswald, medwireNews Reporter