Wolfson Institute of Preventive Medicine, Barts and The London School of Medicine & Dentistry, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK.
Department of Medicine, Physiology and Pharmacology and Community Health Sciences, and Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, AB, Canada.
Eur Heart J. 2021 Jul 1;42(25):2501-2505. doi: 10.1093/eurheartj/ehab274.
There is a causal relationship between dietary salt intake and blood pressure. A reduction in salt intake from the current world average of ∼10 g/day to the WHO recommended level of <5 g/day, lowers blood pressure and reduces the risk of cardiovascular disease and all-cause mortality. However, a few cohort studies have claimed that there is a J-shaped relationship between salt intake and cardiovascular risk, i.e. both high and low salt intakes are associated with an increased risk. These cohort studies have several methodological problems, including reverse causality, and inaccurate and biased estimation of salt intake, e.g. from a single spot urine sample with formulas. Recent studies have shown that the formulas used to estimate salt intake from spot urine cause a spurious J-curve. Research with inappropriate methodology should not be used to refute the robust evidence on the enormous benefits of population-wide reduction in salt intake. Several countries, e.g. Finland, the UK, have successfully reduced salt intake, which has resulted in falls in population blood pressure and deaths from stroke and ischaemic heart disease. Every country should develop and implement a coherent, workable strategy to reduce salt intake. Even a modest reduction in salt intake across the whole population will lead to a major improvement in public health, along with huge cost-savings to the healthcare service.
饮食盐摄入量与血压之间存在因果关系。将盐摄入量从目前世界平均水平的 10 克/天减少到世卫组织建议的<5 克/天，可以降低血压，降低心血管疾病和全因死亡率的风险。然而，一些队列研究声称，盐摄入量与心血管风险之间存在 J 型关系，即高盐和低盐摄入都与风险增加有关。这些队列研究存在一些方法学问题，包括反向因果关系以及盐摄入量的不准确和有偏差的估计，例如来自单一的随机尿液样本的公式。最近的研究表明，用于从随机尿液中估计盐摄入量的公式会导致虚假的 J 型曲线。使用不合适的方法学进行的研究不应被用来反驳关于广泛减少盐摄入量对人群带来巨大益处的可靠证据。一些国家，如芬兰、英国，已经成功地减少了盐的摄入量，这导致了人群血压下降，以及中风和缺血性心脏病的死亡人数减少。每个国家都应制定和实施一项连贯可行的策略来减少盐的摄入量。即使整个人群的盐摄入量略有减少，也将极大地改善公共卫生，并为医疗保健服务节省大量成本。
