Q: I often add oregano to food to fight infections, but I have heard that it lowers testosterone. Should men avoid oregano?

A: Oregano includes substances that inhibit and encourage testosterone formation, but the effects are almost insignificant. Oregano also is an antioxidant that may help fight cancer, heart disease and stroke. It contains compounds that can fight pain, inflammation and infections and stimulate the immune system, but these are present in low levels, so it is not a substitute for medication. Men and women can use oregano as a spice and an herbal tea. It also is available as an essential oil, which should be taken as directed.