Effect of a soy isoflavone supplement on lung function and clinical outcomes in patients with poorly controlled asthma: A randomized clinical trial

Lewis J. Smith, Ravi Kalhan, Robert A. Wise, Elizabeth A. Sugar, John J. Lima, Charles G. Irvin, Allen J. Dozor, Janet T. Holbrook, Nicola Hanania, Marianna Sockrider, Laura Bertrand, Mustafa A. Atik, Blanca A. Lopez, Joan Reibman, Emily DiMango, Linda Rogers, Karen Carapetyan, Kristina Rivera, Newel Bryce-Robinson, Melissa ScheuermanElizabeth Fiorino, John Sundy, Deanna Green, Ankoor Shah, Catherine Foss, Jessica Ghidorzi, Stephanie Allen, Sabrena Mervin-Blake, Elise Pangborn, V. Susan Robertson, Nicholas Eberlein, Michael Land, Brian Vickery, Eveline Wu, Denise Jaggers, James Moy, Edward Naureckas, Mary Nevin, Jenny Hixon, Abbi Brees, Zenobia Gonsalves, Virginia Zagaja, Jennifer Kustwin, Ben Xu, Thomas Matthews, Lucius Robinson, Noopur Singh, Michael Busk, Paula Puntenney, Nancy Busk, Janet Hutchins, Kyle I. Happel, Richard S. Tejedor, Marie C. Sandi, Connie Romaine, Callan J. Burzynski, Arleen Antoine, Jonathan Cruse, Rohit Katial, Flavia Hoyte, Dan Searing, Trisha Larson, Nina Phillips, Holly Currier, Kathryn Blake, Jason Lang, Edward Mougey, Nancy Archer, Deanna Seymour, Mary Warde, Rubin Cohen, Maria Santiago, Ramona Ramdeo, Maureen Dreyfus, Anne E. Dixon, David A. Kaminsky, Thomas Lahiri, Stephanie M. Burns, John Mastronarde, Jonathan Parsons, Janice Drake, Joseph Santiago, David Cosmar, Rachael A. Compton, Sankaran Krishnan, Joseph Boyer, Agnes Banquet, Elizabeth De La Riva-Velasco, Diana Lowenthal, Suzette Gjonaj, Y. Cathy Kim, Nadav Traeger, John Welter, Marilyn Scharbach, Subhadra Siegel, Ingrid Gherson, Lisa Monchil, Tara M. Formisano, Jessica Williams, Mario Castro, Leonard Bacharier, Kaharu Sumino, Jaime J. Tarsi, Brenda Patterson, Terri Montgomery, Raymond G. Slavin, Deborah Keaney Chassaing, Lynn B. Gerald, James L. Goodwin, Mark A. Brown, Kenneth S. Knox, Tara F. Carr, Cristine E. Berry, Fernando D. Martinez, Wayne J. Morgan, Cori L. Daines, Michael O. Daines, Roni Grad, Dima Ezmigna, Monica M. Vasquez, Jesus A. Wences, Silvia S. Lopez, Janette C. Priefert, Monica T. Varela, Rosemary Weese, Katherine Chee, Andrea Paco, Adam Wanner, Richard Lockey, Andreas Schmid, Michael Campos, Monroe King, Eliana S. Mendes, Patricia D. Rebolledo, Johana Arana, Lilian Cadet, Rebecca McCrery, Sarah M. Croker, Shirley McCullough, Gary Salzman, Asem Abdeljalil, Dennis Pyszczynski, Abid Bhat, Patti Haney, Stephen Wasserman, Joe Ramsdell, Xavier Soler, Katie Kinninger, Paul Ferguson, Amber Martineau, Samang Ung, Tonya Greene, W. Gerald Teague, Kristin W. Wavell, Donna Wolf, Denise Thompson-Batt, William C. Bailey, Nicholas Anthonisen, Razan Yasin, Debra Amend-Libercci, Anna Adler, Anne Shanklin Casper, Marie Daniel, Adante Hart, Andrea Lears, Gwen Leatherman, Deborah Nowakowski, Nancy Prusakowski, Sobharani Rayapudi, Alexis Rea, Joy Saams, David Shade, April Thurman, Christine Wei, Alicia Newcomer, Christian Bime, Ellen Brown, Charlene Levine, Suzanna Roettger, Nienchun Wu, Weijiang Shen, Lucy Wang, Johnson Ukken, Stephen C. Lazarus, William J. Calhoun, Michelle Cloutier, Peter Kahrilas, Bennie McWilliams, Andre Rogatko, Christine Sorkness, Scott Sicherer, Gail Weinmann, Michelle Freemer, Robert Smith, Virginia Taggart, Lisa Webber, Gang Zheng, Elizabeth Lancet, Norman H. Edelman, Susan Rappaport

Research output: Contribution to journalArticlepeer-review

40 Scopus citations


IMPORTANCE Soy isoflavone supplements are used to treat several chronic diseases, although the data supporting their use are limited. Some data suggest that supplementation with soy isoflavone may be an effective treatment for patients with poor asthma control. OBJECTIVE To determine whether a soy isoflavone supplement improves asthma control in adolescent and adult patients with poorly controlled disease. DESIGN, SETTING, AND PARTICIPANTS Multicenter, randomized, double-blind, placebo-controlled trial conducted between May 2010 and August 2012 at 19 adult and pediatric pulmonary and allergy centers in the American Lung Association Asthma Clinical Research Centers network. Three hundred eighty-six adults and children aged 12 years or older with symptomatic asthma while taking a controller medicine and low dietary soy intake were randomized, and 345 (89%) completed spirometry at week 24. INTERVENTIONS Participants were randomly assigned to receive soy isoflavone supplement containing 100mg of total isoflavones (n=193) or matching placebo (n=193) in 2 divided doses administered daily for 24 weeks. MAIN OUTCOMES AND MEASURES The primary outcome measurewas change in forced expiratory volume in the first second (FEV1) at 24 weeks. Secondary outcome measures were symptoms, episodes of poor asthma control, Asthma Control Test score (range, 5-25; higher scores indicate better control), and systemic and airway biomarkers of inflammation. RESULTS Mean changes in prebronchodilator FEV1 over 24 weeks were 0.03 L (95%CI, -0.01 to 0.08 L) in the placebo group and 0.01 L (95%CI, -0.07 to 0.07 L) in the soy isoflavone group, which were not significantly different (P = .36). Mean changes in symptom scores on the Asthma Control Test (placebo, 1.98 [95%CI, 1.42-2.54] vs soy isoflavones, 2.20 [95%CI, 1.53-2.87]; positive values indicate a reduction in symptoms), number of episodes of poor asthma control (placebo, 3.3 [95%CI, 2.7-4.1] vs soy isoflavones, 3.0 [95%CI, 2.4-3.7]), and changes in exhaled nitric oxide (placebo, -3.48 ppb [95%CI, -5.99 to-0.97 ppb] vs soy isoflavones, 1.39 ppb [95%CI, -1.73 to 4.51 ppb]) did not significantly improve more with the soy isoflavone supplement than with placebo. Mean plasma genistein level increased from 4.87 ng/mL to 37.67 ng/mL (P < .001) in participants receiving the supplement. CONCLUSIONS AND RELEVANCE Among adults and children aged 12 years or older with poorly controlled asthma while taking a controller medication, use of a soy isoflavone supplement, compared with placebo, did not result in improved lung function or clinical outcomes. These findings suggest that this supplement should not be used for patients with poorly controlled asthma. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01052116.

Original languageEnglish (US)
Pages (from-to)2033-2043
Number of pages11
JournalJAMA - Journal of the American Medical Association
Issue number20
StatePublished - May 26 2015
Externally publishedYes

ASJC Scopus subject areas

  • General Medicine


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