A deficiency in iron may explain that persistent cough.

A deficiency in iron may explain that persistent cough.

If you're plagued by a pesky cough, ask your doctor to check your iron levels. Research presented last fall at a meeting of the American College of Chest Physicians suggests that iron deficiency may help explain why some otherwise healthy, nonsmoking women have persistent coughs.

The study followed 16 women who had chronic cough and a mild deficiency of iron, a mineral that transports oxygen and helps regulate inflammatory responses. "We examined the women before and after three to four months of iron supplementation [according to level of deficiency]," says Caterina Bucca, M.D., of the University of Turin. "After iron supplementation, coughs and signs of laryngitis improved or resolved in most of the women."

Women are more likely than men to suffer unexplained coughs. They're also more likely to have insufficient iron stores because they lose the mineral through menstruation. Bucca says she just put the two together. More research is needed to pinpoint the exact relationship, but Bucca suspects that iron deficiency damages the tissues that line the mouth and nose, back of the throat and trachea, making them more vulnerable to irritants and more prone to ­inflammation. Another reason to eat lean meats and dark leafy greens.