June 2015

Soy Does Not Benefit People with Asthma

A new clinical trial shows that taking 100 mg of soy isoflavones daily for 24 weeks does not improve lung function in people with poorly controlled asthma. Soy isoflavones are the active ingredients in soy. This is contrary to an earlier population study that suggests eating soy foods might benefit lung function.

For more information about soy, view our complete scientific monograph.


  1. Smith LJ, Kalhan R, Wise RA, et al. Effect of a soy isoflavone supplement on lung function and clinical outcomes in patients with poorly controlled asthma: a randomized clinical trial. JAMA. 2015 May 26;313(20):2033-43.

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