"It's unfortunate that a therapy that's advertised as contributing to 'vital living and well-being' would contain potentially unsafe levels of arsenic," said Schenker, who is a professor of Public Health Sciences and a leading authority on occupational and environmental diseases and respiratory illness. "Concentrations of materials contained in herbal supplements, including both the expected benefits and potential side effects, should be studied, standardized, monitored and accurately labeled."
To assess the concentration of arsenic present in commercially available kelp supplements, the UC Davis investigators purchased nine over-the-counter kelp samples from local health food stores. Included were samples from three different batches of the product consumed by the patient.
The researchers sent the samples to the California Animal Health & Food Safety Laboratory in Davis, which operates in partnership with UC Davis, the California Department of Food and Agriculture and others to provide specialized testing that helps protect both human and animal health. Investigators found detectable levels of arsenic in eight of the nine kelp supplements by using a hydride vapor generation method with an inductively coupled argon plasma spectrometer. Seven of the supplements exceeded the tolerance levels for food products set by the U.S. Food and Drug Administration (FDA).
"Part of the problem," said Schenker, "is that the FDA has limited control over dietary supplements. It can't scrutinize products like herbal kelp before they enter the market, so it has to rely on adverse reports to determine product safety."
He noted that none of the kelp products in the study had labels indicating
the presence of arsenic, nor were there any wa
Contact: Carole Gan
University of California, Davis - Health System