Kendig Michael D, Morris Margaret J
Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, Australia.
Asia Pac J Clin Nutr. 2019;28(1):6-14. doi: 10.6133/apjcn.201903_28(1).0002.
Consumption of salt exceeds dietary guidelines for many countries around the world, despite efforts to increase awareness of the potential cardiovascular health risks. Emerging evidence, primarily from rodent models, indicates that high salt intake may also impair aspects of cognitive function. To our knowledge, here we provide the first review of the effects of salt on cognition. To review literature on the effects of high-salt diets on cognitive measures across human and non-human animal research to generate targeted questions for future studies.
Non-systematic literature review of studies manipulating (in rodents) or measuring (in humans) salt intake and assessing performance on cognitive measures.
Studies in humans have focused on older populations and show mixed associations between salt intake and cognitive performance. By contrast, most rodent studies have found impairments in cognition following chronic consumption of high-salt (typically 7-8%) diets. Most report impairments in tasks assessing spatial memory with corresponding increases in hippocampal oxidative stress and inflammatory responses originating in the gut. Notably, several rodent studies reported that high-salt diets impaired cognitive function in the absence of blood pressure changes.
Contrasting results from human and animal studies emphasise the need for further studies to clarify whether salt intake affects cognition. Testing cognition in high-salt diet models that induce hypertension will increase the translatability of future studies in rodents. A challenge for research in humans is isolating the effects of salt from those of fat and sugar that tend to co-occur in 'western' diets.
尽管世界上许多国家都在努力提高人们对心血管健康潜在风险的认识，但盐的摄入量仍超过了膳食指南的建议。新出现的证据（主要来自啮齿动物模型）表明，高盐摄入也可能损害认知功能的某些方面。据我们所知，本文首次对盐对认知的影响进行了综述，旨在回顾关于高盐饮食对人类和非人类动物认知指标影响的文献，从而为未来研究提出有针对性的问题。
对有关操纵（在啮齿动物中）或测量（在人类中）盐摄入量并评估认知指标表现的研究进行非系统性文献综述。
人类研究主要集中在老年人群体，盐摄入量与认知表现之间的关联不一。相比之下，大多数啮齿动物研究发现，长期食用高盐（通常为7%-8%）饮食后会出现认知障碍。大多数研究报告称，在评估空间记忆的任务中存在障碍，同时海马体氧化应激增加，且源于肠道的炎症反应也相应增加。值得注意的是，一些啮齿动物研究报告称，高盐饮食在未引起血压变化的情况下损害了认知功能。
人类和动物研究结果的差异强调了进一步研究以阐明盐摄入量是否影响认知的必要性。在诱导高血压的高盐饮食模型中测试认知能力，将提高未来啮齿动物研究的可转化性。人类研究面临的一个挑战是将盐的影响与“西方”饮食中往往同时存在的脂肪和糖的影响区分开来。
