Researchers have discovered that a naturally occurring compound found in broccoli and other cruciferous vegetables may help protect against respiratory inflammation that causes conditions like asthma, allergic rhinitis and chronic obstructive pulmonary disease.

The research shows that sulforaphane, a chemical in broccoli, triggers an increase of antioxidant enzymes in the human airway that offers protection against the onslaught of free radicals that we breathe in every day in polluted air, pollen, diesel exhaust and tobacco smoke.

Free radicals are atoms or groups of atoms with an odd number of electrons that can cause oxidative tissue damage, which leads to inflammation and respiratory conditions like asthma.

Asthma is a chronic lung disease that inflames and narrows the airways. Asthma causes recurring periods of wheezing, chest tightness, shortness of breath, and coughing. In the United States, more than 22 million people are known to have asthma.

People who have asthma have inflamed airways and this makes the airways swollen and very sensitive. They tend to react strongly to certain substances that are breathed in.

In the study, 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 do not contain the compound, served as a placebo.

Rinses of nasal passages were collected at the beginning and end of the study to assess the gene expression of antioxidant enzymes in cells of the upper airways. Researchers found significant increases of antioxidant enzymes at broccoli sprout doses of 100 grams and higher, compared with the placebo group.

The maximum broccoli sprout dosage of 200 grams generated a 101-percent increase of an antioxidant enzyme called GSTP1 and a 199-percent increase of another key enzyme called NQO1.

No serious side effects occurred in study participants receiving broccoli sprouts, demonstrating that this may be an effective, safe antioxidant strategy to help reduce the inflammatory impact of free radicals.

This strategy may offer protection against inflammatory processes and could lead to potential treatments for asthma and other respiratory conditions.

Marc Riedl, study author notes that more research needs to be done to examine the benefits of sulforaphane for specific respiratory conditions. It is too early to recommend a particular dosage.
References:
1. Marc Riedl, et al. University of California - Los Angeles.
2. National Institutes of Health.