Airborne effects unstudied

CATCHY packaging and celebrity endorsements have done much to make Airborne a hot seller among consumers eager to keep colds and flu at bay. The product, famously created by a schoolteacher who was tired of catching germs from her students, racked up more than $100 million in sales in 2006, after just a few years on the market.

Though individual consumers swear by the product and write to the company with testimonials of their satisfaction, hard evidence of the dissolvable tablets’ efficacy is nonexistent.

The ability of Airborne’s unique combination of 17 herbs, vitamins and minerals to cure or prevent colds or the flu hasn’t been independently studied. The company cites the results of a small clinical trial on its website, but the results haven’t been published or made publicly available.

The product contains popular remedies, including zinc, vitamin C and echinacea, which are likely of limited use in preventing colds or the flu. It also includes herbs such as lonicera and forsythia, which are far less studied for colds and flu. And three Airborne tablets -- the recommended daily dose -- provide more than the safe daily limit of vitamin A. A one-time overdose of vitamin A can cause headaches and nausea; over time, too much of the vitamin can cause bone weakness and dry, cracked skin.