Salt and asthma
Asthma
Bronchial reactivity is linked to sodium balance. Epidemiological evidence suggests that the severity of asthma may relate to salt intake in different countries (1) . Furthermore, a double-blind study of modest salt restriction caused a reduction in the severity of asthma attacks and a reduction in the use of medication and an improvement in the measurement of airways resistance (2) . The changes seen were only significant in males. A more recent study illustrates the mechanism whereby a higher salt intake exacerbates asthma (3) .
It seems therefore that, while salt is not a direct cause of asthma, a high salt intake can act as a major aggravating factor.
References
(1) Burney P. A diet rich in sodium may potentiate asthma. Epidemiologic evidence for a new hypothesis. Chest. 1987;91:143S-148S.
(2) Carey O J, Locke C, Cookson J B. Effect of alterations of dietary sodium on the severity of asthma in men. Thorax. 1993;48:714-8.
(3) Mickleborough T D, Lindley M R, Ray S. Dietary salt, airway inflammation, and diffusion capacity in exercise-induced asthma. Med Sci Sports Exerc. 2005;37:904-14.