Leonardo Di Caprio's Frank Abagnale Jr. in "Catch Me If You Can" and Freddy Benson (Steve Martin) in "Dirty Rotten Scoundrels" prove just how much folks love a con man - movie-goers laid out more than $200 million to see these tricksters.

But that's nothing compared with the $15 BILLION spent in one year (2007) on "alternative" supplements - many herbal - that are phonier than Abagnale's medical degree and Freddy's disability.

A recent study looked at 44 herbal products from 12 companies, 30 species of herbs and 50 leaf samples to see if their contents were related IN ANY WAY to what their labels stated.

-59 percent of the products contained material from plants NOT listed on the label.

-Just 48 percent contained what they claimed as the active ingredient. Of those, 1/3 were contaminated with ingredients and fillers; some that pose health risks.

-Only two of 12 companies delivered what they promised on the label without any substitutions.

The Food and Drug Administration says store shelves contain more than 300 "adulterated" supplements, some with unidentified prescription medications, others with heavy metals that up the risk of heart attack, stroke and death.

What can you do?

-Rely on an ingredients certification seal from the United States Pharmacopeial Convention. Five companies (go to usp.org) have earned them.

-Remember, even reliable supplements are just that! They're meant to supplement, not substitute for, a healthy lifestyle.

© 2013 Michael Roizen, M.D. and Mehmet Oz, M.D.
Distributed by King Features Syndicate, Inc.