January 3, 2001 CHICAGO (AP) - Hair analysis is generally an unreliable method of diagnosing nutritional problems and exposure to environmental toxins, according to a study of six commercial laboratories.
A hair sample sent to all six labs produced widely varying and often opposite results. One lab called the patient a "fast metabolizer" and recommended that she abstain from vitamin A; another said the sample showed she was a "slow metabolizer" who should take vitamin A supplements.
"Health-care choices based on these analyses may be ineffective or even detrimental to the patient's overall health," the researchers said in Wednesday's Journal of the American Medical Association.
A similar study made a similar warning in the same journal 15 years ago. Because laboratory methods have generally improved since then and a federal law was passed in 1988 to regulate testing, the researchers decided to re-examine the issue.
The hair - supplied by one of the researchers - was not tested for illegal drugs such as cocaine, which is another common use of hair analysis. The researchers did not pass judgment on the reliability of hair tests to detect drug use.
The authors, from the California Department of Health Services, said the federal government should refrain from certifying hair analysis laboratories until standards for proficiency testing are developed.
The researchers said an average of 225,000 hair mineral tests costing $9.6 million are performed yearly by nine labs nationwide. They focused on six, whose charges ranged from $30 to $69 per sample to test for levels of poisons such as arsenic and 18 other elements, including lead and mercury.
Because of the findings, health care professionals should reconsider the use of hair analysis to assess a patient's nutritional health, Steven Steindel of the Centers for Disease Control and Prevention and Dr. Peter Howanitz of the State University of New York in Brooklyn wrote in an accompanying editorial.
Copyright 2001 The Associated Press. All rights reserved.
