Researchers at the University of California, Los Angeles, said that the naturally occurring compound found in broccoli -- sulforaphane -- and other cruciferous vegetables may help protect against respiratory inflammation that causes conditions such as asthma, allergic rhinitis and chronic obstructive pulmonary disease.
"This is one of the first studies showing that broccoli sprouts -- a readily available food source -- offered potent biologic effects in stimulating an antioxidant response in humans," Dr. Marc Riedl, the study's principal investigator said in a statement.
"We found a two- to three-fold increase in antioxidant enzymes in the nasal airway cells of study participants who had eaten a preparation of broccoli sprouts."
This strategy may offer protection against inflammatory processes and could lead to potential treatments for a variety of respiratory conditions, Riedl added.
The UCLA team worked with 65 volunteers who were given varying oral doses of either broccoli or alfalfa sprout preparations for three days. Broccoli sprouts are the richest natural source of sulforaphane; the alfalfa sprouts, which don't contain the compound, served as a placebo.
The study, published in the journal Clinical Immunology, found the maximum broccoli sprout dosage generated a 101-percent increase of the antioxidant enzyme GSTP1 and a 199-percent increase of another key enzyme NQO1.