Copenhagen Lupus and Vasculitis Clinic VRR4242, Copenhagen University Hospital, Rigshospitalet Blegdamsvej 9, Copenhagen DK-2100, Denmark.
Nephrol Dial Transplant. 2016 Sep;31(9):1398-403. doi: 10.1093/ndt/gfw280. Epub 2016 Aug 3.
Scientific evidence to support the recommended salt intake of < 5.8 g/day is virtually non-existingent. There are no randomized controlled trials (RCTs) to investigate the effect of salt reduction (SR) below 5.8 g on health outcomes. The effect of SR on blood pressure (BP) reaches maximal efficacy at 1 week. RCTs in healthy individuals lasting at least 1 week show that the effect of SR on BP is <1 mmHg, but that SR has significant side effects, including increases in renin, aldosterone, noradrenalin, adrenalin, cholesterol and triglyceride. Still, disregarding confounders and side effects, health authorities use BP effects obtained in studies of pre-hypertensive and hypertensive patients to recommend SR in the healthy population and use these biased BP effects in statistical models indirectly to project millions of saved lives. These fantasy projections are in contrast to real data from prospective observational population studies directly associating salt intake with mortality, which show that salt intake <5.8 g/day is associated with an increased mortality of ∼15%. The population studies also show that a very high salt intake >12.2 g is associated with increased mortality. However, since <5% of populations consume such high amounts of salt, SR at the population level should not be a public health priority. Consequently, this policy should be abolished, not because any attempt to implement it has failed, and not because it costs taxpayers and food consumers unnecessary billions of dollars, but because-if implemented-it might kill people instead of saving them.
支持每日摄入盐量<5.8 克建议的科学证据几乎不存在。没有随机对照试验(RCT)来研究盐摄入量减少(SR)至 5.8 克以下对健康结果的影响。SR 对血压(BP)的影响在 1 周时达到最大疗效。在健康个体中持续至少 1 周的 RCT 表明,SR 对 BP 的影响<1mmHg,但 SR 有显著的副作用,包括肾素、醛固酮、去甲肾上腺素、肾上腺素、胆固醇和甘油三酯的增加。尽管如此,健康当局不顾混杂因素和副作用,仍使用在高血压前期和高血压患者研究中获得的 BP 效应来建议健康人群进行 SR,并在统计模型中间接使用这些有偏的 BP 效应来预测数以百万计的挽救生命。这些虚幻的预测与直接将盐摄入量与死亡率相关联的前瞻性观察人群研究的真实数据形成对比,这些研究表明,盐摄入量<5.8 克/天与死亡率增加约 15%相关。人群研究还表明,盐摄入量非常高(>12.2 克)与死亡率增加有关。然而,由于只有<5%的人群摄入如此高的盐量,因此在人群层面上进行 SR 不应成为公共卫生的重点。因此,应该废除这项政策,不是因为任何实施它的尝试都失败了,也不是因为它让纳税人和食品消费者花费了数十亿美元的不必要开支,而是因为——如果实施——它可能会杀人而不是救人。