Kelp Contamination Alert

DAVIS, Calif.In laboratory analysis and at least one case study, kelp was found to contain higher levels of arsenic than allowed by the Food and Drug Administration (FDA), after having caused a string of ill side effects, including hair (alopecia) and memory loss, a severe rash, fatigue, nausea and vomiting in one case report; officials reported these symptoms dissipated after those affected ceased supplementation.

As a part of the investigation, University of California, Davis, researchers analyzed nine samples of kelp randomly obtained from local health food stores. Eight of the nine samples showed detectable levels of arsenichigher than the FDA tolerance level of 0.5 to 2 ppm for certain food products; yet, none of the product tests provided information regarding the possibility of contamination with arsenic or other heavy metals.

In the case report, published in Environmental Health Perspectives (115:4, 2007), a 54-year-old woman, referred to the University of California, Davis, Occupational Medicine Clinic, had a two-year history of worsening alopecia and memory loss. Taking daily kelp supplements, she had an arsenic level of 83.6 µg/g creatinine (normal < 50 µg/g creatinine) in her urine sample. Within weeks of discontinuing the kelp supplements, her symptoms resolved and arsenic blood and urine levels returned to normal.