摘要：大多数健康专家认为，过多摄入食盐有害健康，具体表现在增高血压，增加罹患心脏病、中风的危险。而美国疾病控制与预防中心的一个研究小组发现，饮食中“多盐少钾”更不利于健康，会增加人的死亡风险。
研究人员在新一期《内科学文献》上发表论文说，他们从美国的健康普查资料入手，分析了超过1.2万名民众在15年间摄入钠、钾元素与死亡率的联系。结果发现，过多摄入食盐会导致因多种疾病而死亡的风险上升20%，而增加钾的摄入可将死亡风险降低20%。
他们还发现，钠钾比例高的“高盐低钾”膳食结构最具危险性。饮食中钠钾比例最高的人群和饮食中钠钾比例最低的人群相比，死亡风险高46%，特别是，罹患冠心病而死亡的风险要高一倍以上。
参与此项研究的埃莱娜·库克琳娜博士说，食盐中的钠元素会提高血压，钾元素则具有降血压的抵消作用，更应该注重研究钾和盐的平衡。她说，“多钾少钠”的膳食更为健康，饮食中应多增加水果、蔬菜和低脂乳制品。
对于这一发现各方有不同的评价。纽约市健康与精神卫生局的托马斯·法利博士等人在同期《内科学文献》上发表评论说，此前已有调查发现“高盐低钾”膳食与高血压和心血管疾病的关系，新发现提供了有力证据予以支持。而美国食盐工业组织并不认可。
世界卫生组织推荐成年人每天摄入食盐不高于5克，美国人平均食盐摄取量是其2倍，约90%美国人钠摄取量超标。餐馆的菜肴和商店销售的深加工食品中，普遍钠含量较高。
生物探索推荐英文论文摘要：
Sodium and Potassium Intake and Mortality Among US Adults
Prospective Data From the Third National Health and Nutrition Examination Survey
Background Several epidemiologic studies suggested that higher sodium and lower potassium intakes were associated with increased risk of cardiovascular diseases (CVD). Few studies have examined joint effects of dietary sodium and potassium intake on risk of mortality.
Methods To investigate estimated usual intakes of sodium and potassium as well as their ratio in relation to risk of all-cause and CVD mortality, the Third National Health and Nutrition Examination Survey Linked Mortality File (1988-2006), a prospective cohort study of a nationally representative sample of 12 267 US adults, studied all-cause, cardiovascular, and ischemic heart (IHD) diseases mortality.
Results During a mean follow-up period of 14.8 years, we documented a total of 2270 deaths, including 825 CVD deaths and 443 IHD deaths. After multivariable adjustment, higher sodium intake was associated with increased all-cause mortality (hazard ratio [HR], 1.20; 95% confidence interval [CI], 1.03-1.41 per 1000 mg/d), whereas higher potassium intake was associated with lower mortality risk (HR, 0.80; 95% CI, 0.67-0.94 per 1000 mg/d). For sodium-potassium ratio, the adjusted HRs comparing the highest quartile with the lowest quartile were HR, 1.46 (95% CI, 1.27-1.67) for all-cause mortality; HR, 1.46 (95% CI, 1.11-1.92) for CVD mortality; and HR, 2.15 (95% CI, 1.48-3.12) for IHD mortality. These findings did not differ significantly by sex, race/ethnicity, body mass index, hypertension status, education levels, or physical activity.
Conclusion Our findings suggest that a higher sodium-potassium ratio is associated with significantly increased risk of CVD and all-cause mortality, and higher sodium intake is associated with increased total mortality in the general US population.
