04.14.10
St. John's Wort has been shown to be effective in treating mild to moderate forms of major depression, but a new report from ConsumerLab.com, White Plains, NY, shows that few of the herbal supplement brands recently tested met quality standards. Among the 10 St. John's Wort supplements selected for testing, only four met ConsumerLab.com’s quality standards. Americans purchased $55 million of St. John's Wort supplements in 2008, according to the Nutrition Business Journal, down significantly from a high of $315 million in 1998.
St. John’s Wort is known to accumulate heavy metals from the soil. Four supplements failed testing due to contamination with cadmium, a heavy metal that is a carcinogen and a kidney toxin. Levels ranged from 0.18 to 0.86 micrograms of cadmium per gram of herb or extract in the four products. One of these products was also contaminated with an amount of lead that, although small, would necessitate a warning label in the State of California. Although each of these products alone does not pose a health risk, they represent avoidable sources of contaminants, ConsumerLab.com claims.
Three products, including one of those contaminated with cadmium, contained only 23% to 36% of St. John's Wort plant chemicals (hypericin or hyperforin) expected from their labels.