Hair analysis is the chemical analysis of a hair sample. It is used in some branches of alternative medicine as a method of investigation to assist diagnosis. Its use is controversial.

Background

In hair analysis the levels of minerals and metals in the hair sample are analyzed. Advocates report that the results allow them to diagnose mineral deficiencies, heavy metal poisoning and that patients afflicted by conditions such as autism have anomalous hair test results.^[1] That hair mineral analysis can be used to diagnose some heavy metal toxicities is undisputed by toxicologists and routinely recognized in courts of law.^[2]

As of 1998, "the 9 commercial 'nutritional hair analysis' laboratories currently operating in the United States, 3 indicate that they primarily use ICP-MS, 4 primarily use ICP-AES, and 1 reports use of directly coupled plasma (DCP)-AES. DCP-AES is an older technique that is potentially less stable than ICP-AES. On average, these laboratories measure 26 elements per hair sample. Nutritional hair analysis laboratories require between 0.3 and 1 gram for the AES methods, and 0.25-1 gram for ICP-MS."^[3] The amount selected depends on the analytical method used, but sample sizes in the 50 milligram range are reported.^[4]

Inconsistent results

In a 1985 investigation of 13 commercial laboratories published in the Journal of the American Medical Association noted inconsistencies and questionable content in their reports and recommendations:

"Hair samples from two healthy teenagers were sent under assumed names to 13 commercial laboratories performing multimineral hair analysis. The reported levels of most minerals varied considerably between identical samples sent to the same laboratory and from laboratory to laboratory. The laboratories also disagreed about what was "normal" or "usual" for many of the minerals. Most reports contained computerized interpretations that were voluminous, bizarre, and potentially frightening to patients. Six laboratories recommended food supplements, but the types and amounts varied widely from report to report and from laboratory to laboratory. Literature from most of the laboratories suggested that their reports were useful in managing a wide variety of diseases and supposed nutrient imbalances. However, commercial use of hair analysis in this manner is unscientific, economically wasteful, and probably illegal."^[5]

The authors did not explicitly rule out further diagnostic uses for hair mineral analyses in the future, but listed three issues that prevent hair mineral tests provided by the sampled labs from being accepted as scientifically sound and clinically viable: a lack of standardization and general agreement on the techniques by which hair mineral content was to be determined, a lack of general consensus on the meaning of hair mineral content analyses, and a lack of agreement on treatments for putative imbalances.^[5]

In 2001 a follow up investigation was conducted to see if things had improved since the 1985 investigation. The authors concluded:

"Hair mineral analysis from these laboratories was unreliable, and we recommend that health care practitioners refrain from using such analyses to assess individual nutritional status or suspected environmental exposures. Problems with the regulation and certification of these laboratories also should be addressed."^[6]

Tests have shown that levels of heavy metal in the body may not be reflected by the levels in the hair.^[7]

Other investigations have shown considerable reliability from various hair analysis results for body uptake or absorption of nutritional elements and for toxic materials. Hair analysis has been recognized in courts as proof of use, or non-use, of illegal drugs, steroids etc.

Isotopic ratios differ slightly by location. Measuring the isotopic fingerprint in a hair sample as a function of distance from the scalp suggests a record of an individual's gross geographic movements.^[8]

Peer-reviewed studies that suggest further uses for hair mineral analysis in medicine

Despite this lack of consensus, there is some evidence to suggest that hair analyses can be a useful tool in both medical research and in clinical diagnostics. Studies have found statistically significant differences between healthy people and people with autism, multiple sclerosis, children with learning disabilities, dementia, protein deficient diets, and histories of violent criminal behavior.

• A 2003 study in the International Journal of Toxicology found that hair mercury levels in autistic infants do, indeed, significantly differ from those in healthy children.^[9] One of the co-authors of this paper was the chairman of the chemistry department at the University of Kentucky.^[10]

• A 1978 study by researchers at Dalhousie University found that "when scalp-hair samples from 40 multiple sclerosis patients and 42 controls were analyzed, ...highly significant differences (99% confidence) were observed between the two groups in concentrations of Cu, l, Mn, S, Se, and V.^[11]

Illnesses are diagnosed by measuring markers that prove the presence of a clear distinguishing difference between healthy persons and those with the illness in question. Presently, Multiple Sclerosis is diagnosed, as circumstances dictate, by means of a physical examination, an MRI test, or lumbar puncture into the spine.

• A preliminary 1986 study in the Journal of the Royal Society of Medicine of hair metal concentrations in "long-stay hyperactive mentally handicapped children and agitated senile dements" found that in the children "the only metals showing significant differences at the P= 0.01 level were lead and zinc. Zinc was significantly low in the hyperactive children when compared with the controls, and lead was raised (Student's t test.) In the blood analyses, neither metal showed any statistically significant difference between the groups." The specific measurements were

• hair lead: hyperactives (N=20) average= 15.1 ?g/g, standard deviation = 1.8 ?g/g, controls: hair lead (N=20) average= 5.3 ?g/g, standard deviation= 2.9?g/g

• blood lead: hyperactives (N=20): average= 9.4 ?g/dl, standard deviation=7.2 ?g/dl, controls (N=20): average= 6.0 ?g/dl, standard deviation = 4.3 ?g/dl.

• hair zinc: hyperactives (N=20) average = 97.5 2.9?g/g, standard deviation = 14.7?g/g, controls (N=20): average = 123 ?g/g standard deviation= 12.6 ?g/g

• serum zinc: hyperactives (N=20): average = 83.2 ?g/dl standard deviation = 11.8 ?g/dl, controls (N=20): average = 87.6 ?g/dl standard deviation= 12.4 ?g/dl

The study continued: "The results of the agitated senile dementia patients ... The only significant difference at the P= 0.01 level was for aluminium, with the agitated patients showing a raised level compared to controls." The actual measurements were:

• agitated senile dementia patients (N=22, gender=F) average=19.5 ?g/g, standard deviation= 11.1 ?g/g. Control patients (N=20, gender=F) average= 9.3 ?g/g, standard deviation= 7.4 ?g/g

It is merely to repeat the words of the authors to note that whereas they were unable to identify any significant differences between the hyperactives and controls and the agitated senile dementia patients and controls, whereas this was possible by means of hair analysis. ^[12]

• A 1972 study of hair analysis in 41 healthy Indonesian children and 40 protein-deficient Indonesian children found that average hair manganese was five times higher and hair sodium was 2.5 times higher in the protein deficient children. The author concluded: "The physiological significance of these results is obscure... Despite their statistical significance, the increases are not consistent enough for diagnostic use in individual subjects."^[13]

• A 1991 study found that in recently incarcerated inmates, "significantly elevated manganese levels were found in the hair of violent versus nonviolent subjects (P less than .0001)."^[14] Another study, dating to 1989 found that hair testing was able to correctly identify 86% of the violent and 78% of the nonviolent inmates (N= 40+40) that it studied.^[15]

References

External links

• AETNA Clinical Policy Bulletin: Hair Analysis
• Quackwatch: Commercial Hair Analysis: A Cardinal Sign of Quackery
• Study Questions Reliability of Hair Tests