Beard T C
Menzies Centre for Population Health Research, University of Tasmania, Australia.
J Cardiovasc Pharmacol. 1990;16 Suppl 7:S35-8.
In urban Australia, the risk of retiring with hypertension is greater than 40%, and the basic abnormality--a rise in blood pressure (BP) with age--is almost universal. A hypothesis linking this with salt, therefore, concerns everyone. The diet of early humans was unsalted, and the Na content of breast milk (6 mmol/kg) shows how little NaCl is needed even during the most rapid period of growth. The hypothesis that the hypertonic concentration needed to preserve food causes the BP to rise with age is based partly on the normotensive status of contemporary "salt-free" societies and partly on experimental evidence. "Salt-free" populations seldom use alcohol and happen to be lean and active, with a low fat intake and largely vegetarian diet, but Westerners with similar virtues do not escape hypertension. Ideally, the prophylactic effect of avoiding salt would be ascertained in large-scale, prospective trials, but practical, ethical and, economic factors impose serious design problems. Nevertheless, a public health intervention based on this hypothesis would be incomplete without a serious attempt to measure the outcome.
在澳大利亚城市地区，患高血压退休的风险超过40%，而且基本异常情况——血压（BP）随年龄升高——几乎普遍存在。因此，一个将此与盐联系起来的假设关乎每个人。早期人类的饮食是无盐的，母乳中的钠含量（6毫摩尔/千克）表明，即使在生长最快的时期，所需的氯化钠也极少。认为保存食物所需的高渗浓度会导致血压随年龄升高的假设，部分基于当代“无盐”社会的血压正常状态，部分基于实验证据。“无盐”人群很少饮酒，碰巧身材苗条且活跃，脂肪摄入量低且大多为素食，但具备类似优点的西方人却无法避免患高血压。理想情况下，避免盐的预防效果应在大规模前瞻性试验中确定，但实际、伦理和经济因素带来了严重的设计问题。然而，如果不认真尝试衡量结果，基于这一假设的公共卫生干预将是不完整的。
