Oral contraceptives may offer women an unexpected side effect: fewer asthma symptoms.
Researchers at McMaster University in Canada studied 17 women with asthma during their menstrual cycles.
They found women using birth control pills had fewer inflammatory markers known to cause asthma attacks.
Researchers were looking at levels of exhaled nitric oxide as a measurement for asthma symptoms.
They also found those markers could be higher or lower depending on where a woman was in her cycle -- and say medication could be prescribed to counteract those changes.
The scientists published their findings in the journal CHEST, November 2009.
