Shortness of breath and a persistent wheeze plague 400 million asthmatics worldwide. As that number continues to grow, more people are looking to natural alternatives to bronchodilators, whose expense and side effects have some questioning their efficacy. Passion fruit might be the solution, according to a new study published in Nutrition Research. Over the course of four weeks, 42 asthmatics with an average age of about 36 years participated in a random, double-blind trial. Half the group was administered 150 mg per day of bioflavonoid-rich purple passion fruit (PPF) peel extract, while the rest took a placebo.

After a month, fewer than 20 percent of the PPF-extract-taking subjects experienced wheezing, compared with about 80 percent of subjects in the placebo group. Coughing also decreased by 76 percent in the PPF group, versus 47 percent in the placebo group. Although these findings show promise in helping control severe asthma symptoms, PPF extract did not seem to bring on any significant increase in actual lung function; forced expiratory volume—the amount of oxygen expelled over 1 second—did not improve in either group. Researchers say PPF extract could be available to consumers in pill form by the end of 2009.