According to a July study from the National Center for Complementary and Alternative Medicine, based on interviews with more than 23,300 adults during the 2007 National Health Interview Survey, almost 40% of adults use some form of complementary and alternative medicine to treat a variety of conditions.

They spent about $33.9 billion on these practices in 2007, accounting for about 11.2% of the public’s total out-of-pocket health expenditures. In 1997, the last time such a survey was taken, the figure was $27 billion. Read the story by Tammy Worth in the LA Times.