Description Module
The Description Module contains narrative descriptions of the clinical trial, including a brief summary and detailed description. These descriptions provide important information about the study's purpose, methodology, and key details in language accessible to both researchers and the general public.
Description Module path is as follows:
Study -> Protocol Section -> Description Module
Description Module
Ignite Creation Date:
2025-12-26 @ 10:57 AM
Ignite Modification Date:
2025-12-26 @ 10:57 AM
NCT ID:
NCT00741208
Brief Summary:
The purpose of this study is to determine if dietary supplementation with soy isoflavones in persistent asthma improves airway reactivity as determined by PC20 to methacholine.
Detailed Description:
Asthma is a complex disease whose prevalence and severity are determined by multiple genetic and environmental factors. The prevalence of asthma has increased during the past few decades. Although causal relationships have not been proven, changing dietary practices have paralleled the increase in asthma prevalence. Several surveys have found an association between reduced lung function and decreased consumption of antioxidants, flavonoids, and essential vitamins in a variety of respiratory conditions including asthma. These findings suggest that diet may be a factor that impacts asthma and its clinical manifestations.
Higher dietary consumption of soy isoflavones is associated with decreased self-report of cough and other allergic respiratory symptoms. Our group reported an inverse relationship between dietary intake of the soy isoflavone genistein and asthma severity. In addition, we recently demonstrated that genistein inhibits synthesis of cysteinyl-leukotrienes in eosinophils by blocking p38-dependent activation of 5-lipoxygenase, providing a plausible cellular mechanism for the benefit of soy isoflavones in asthma. We also documented that dietary soy isoflavone supplementation in asthma patients inhibited eosinophil cysteinyl-leukotriene synthesis and decreased exhaled nitric oxide, an indicator of eosinophilic airway inflammation. Our overall long-term goal is to translate these epidemiological and mechanistic findings to human disease and determine whether dietary soy isoflavones have a clinical role in asthma. We propose a clinical study powered to detect an improvement in lung function as the first stop in achieving this goal.
Our hypothesis is that dietary supplementation with isoflavones will improve lung function, reduce symptoms, and decrease airway inflammation in asthma. To test this, we will conduct a randomized placebo-controlled, cross-over study of soy isoflavone supplementation in patients with persistent asthma.
Study:
NCT00741208
Study Brief:
Protocol Section:
NCT00741208