A randomized trial of children and adults revealed that the use of soy isoflavone did not result in improved lung function or clinical outcomes in asthma patients.
The researchers found that average changes in pre-bronchodilator forced expiratory volume in the first second (FEV1) over 24 weeks were not significantly different between the soy isoflavone group and the placebo group. The supplement also did not improve other aspects of asthma control, including additional measures of lung function, symptoms, quality of life, and airway and systemic inflammation.
“These findings suggest that this supplement should not be used for patients with poorly controlled asthma,” the authors conclude.
