Does a low sodium diet improve asthma control?

Zara E.K. Pogson, et al., Does a Low Sodium Diet Improve Asthma Control?  American Journal of Respiratory Critical Care, 2008; 178(3):132.

Observational studies and initial randomized trials had indicated that a low sodium diet might improve asthma control.  This randomized double-blind placebo-controlled trial examined the use of a low sodium diet as an adjunctive therapy to normal treatment and found salt reduction has no additional therapeutic benefit in adults with asthma and bronchial reactivity to methacholine.