Hair analysis is commonly used by alternative health practitioners to indicate a range of things, from macronutrient, mineral and vitamin deficiencies, through to food allergies and intolerances and even the presence of, or past infection with pathogens.
But is this testing method valid?
Hair analysis is used in mainstream science, specifically with respect to forensic inquiry and the evaluation of poisoning and toxicity. Hair analysis can indicate the presence of a mineral or metal and hence its use for toxicity testing in some cases, although it cannot reliably determine the dose.
Potential toxic metals such as arsenic, cadmium, cobalt, germanium, lead, lithium, manganese, mercury, nickel, and thallium, show relationships between hair and body burden, dosage, and exposure or toxicity and some heavy metal nutrients (chromium, selenium and zinc) may be somewhat reliably measured within hair (1). Hair mineral analysis specifically is not considered usable for individual diagnostics with two exceptions—arsenic and methylmercury because of large variations in individual and environmental influences and sources of error of the method of analysis. However mineral analysis of the hair can be used for cadmium, lead, and zinc in order to compare a single person with a larger population (2).
Hair testing though is commonly used in complementary and alternative medicine (CAM) to try to determine a range of health factors ranging from mineral, vitamin, fatty acid and amino acid deficiencies and life events such as past infection but there are significant complications when people try to extend the usefulness of hair testing.
Complications of Hair Analysis
There are many complications that may affect the viability of hair tissue analysis (3).
- Hair tested
Due to significant variation in tissue variation the site, distance from skin and hair type need to be standardised, and this hasn’t been tested or validated.
2. Time to test
Time between the hair being taken and testing will affect the viability of many results, especially those of water soluble vitamins.
3. Exposure to other elements
Hair dyes, shampoos, soaps and conditioners can all affect the viability and results from a hair test. This poses another significant challenge to the validity and standardisation of test results.
4. Stripping of components in hair
The factors mentioned above, along with handling and environmental conditions can all serve to strip some of the structural components of hair and thus the minerals, vitamins or other nutrients or toxins that they may contain.
5. Variation between individuals and lack of standardisation
There is considerable variation between the mineral levels found in hair, and there currently is very poor standardisation currently between labs, within labs and with any accepted reference ranges for hair testing and how that might relate to organ, blood and other mineral or vitamin content.
What does the literature say?
Evidence from systematic reviews suggest that hair mineral analysis may be a reliable indicator of zinc status (4).
Some heavy metals (especially cadmium and lead and magnesium) that are environmental pollutants may disturb behaviour in children (5, 6) and adults (7, 8). It is possible that higher levels of lead, cadmium, mercury, copper, iron, and silicon and lowered levels of lithium (as determined by hair test) may be correlated with behavioural difficulties (9). Hair analysis is considered a useful test for determining mercury intoxication (10). A correlation has also been noted between high levels of aluminium, arsenic, cadmium, mercury, antimony, nickel, lead, and vanadium in hair and autism symptoms in children (11, 12) and possibly in conjunction with low-levels of zinc and magnesium (13).
Some minerals such as arsenic, selenium, and probably iodine, zinc, sodium, and vanadium contribute to regulation of cancer and it has been suggested that hair analysis and multiple logistic regression analysis is a potential tool for estimating cancer risk (14).
Accumulations of manganese, iron, lead, cadmium and aluminium in hair from Mongolian men (compared to a Japanese control) were correlated with arthritis and Parkinonisms (15) and concentrations of calcium, magnesium, iron, and manganese may be higher in the hair of female patients with fibromyalgia (16).
These results are both highly preliminary and are correlatory, showing no definite causative effect. There are also conflicting results and a lot more research is required to show any clear causative nature of mineral imbalances and for example autism, and the usefulness of a hair test in indicating this.
A study published in the Journal of the American Medical Association in which hair samples from two healthy teenagers were sent under assumed names to 13 commercial laboratories performing multimineral hair analysis showed that the reported levels of most minerals varied considerably between identical samples sent to the same laboratory, and from laboratory to laboratory (17).
Seidel and colleagues (18) sent a sample of hair to six laboratories for analysis. 10-fold differences in mineral concentrations were reported by the labs with statistically significant (P<.05) extreme values reported for 14 of the 31 minerals analysed. Differences were also found in laboratory sample preparation methods, calibration standards and reference ranges used by the individual labs with conflicting dietary and supplement advice provided based on the results. A study conducted in Germany concluded similarly that the extreme variations in results between labs make hair testing an unreliable testing method (19). A more recent 2013 study conducted in Korea sent samples from a young male to three different labs noting similar procedures and methods and similar test results, however a lack of standardisation of reference ranges was still present (20).
In 2008 Brazilian researchers attempted to determine the relationship of hair levels of minerals to blood levels. For copper, manganese and strontium there was no correlation between levels in hair and blood. The authors concluded there was little value in hair analysis for determining copper, manganese, strontium of lead exposure (21).
A 2004 review published in the journal Allergies found that verified allergies were seldom picked up by Hair Analysis in most labs, with significant findings of false allergies (22), for example the ability to diagnose allergic disease was studied in nine fish-allergic and nine control subjects, who provided specimens of blood and hair for testing. All fish-allergic subjects had previously been shown to have a positive skin prick test to fish. The specimens were submitted as coded, duplicate samples to five laboratories which all offer a commercial service in carrying out diagnostic tests for allergy. All five laboratories were not only unable to diagnose fish allergy but also reported many allergies in apparently non-allergic subjects and provided inconsistent results on duplicate samples from the same subject (23).
An attempt has also been made to correlate body levels of minerals with hair analysis in autopsy. A significant correlation was found between mercury levels in hair and in the kidney, however only weak associations were found between hair levels of mercury and selenium with liver concentrations. Overall mineral concentrations between tissue types varied enormously (in some cases more than 5000-fold) and it was concluded that with the exception of mercury and possibly selenium that hair analysis does not provide a useful measure of trace element status (24).
The bottom line
If we were to be able to use hair analysis as a consistent diagnostic tool it would be extremely useful because it is non-invasive and extremely convenient in a clinical setting. However it has not yet been proven to be reliable, nor accurate to consistently reflect the status of trace elements, vitamins or macronutrients in the body. It is also in all likelihood (at this stage) not a reliable measure of allergy or disease status and may serve to further confuse clients and patients and risk scaring them unnecessarily. We also have at this point little knowledge of accurate reference ranges for hair analysis and the variation between tests and the comparison with serum or other tissue samples (25) which makes it difficult to use diagnostically for the few minerals for which it may offer a more reliable test (26).
In short—while enticing, at this stage the evidence for hair testing, especially for the range of outcomes that many purveyors claim, is simply not backed by credible evidence.
We suggest avoiding hair analysis for the time-being.
“there are so many confounding factors that influence these measurements that isolated individual results cannot be relied upon. Their current value is in epidemiological studies” (27).
1. Shamberger, R.J., Validity of hair mineral testing. Biological Trace Element Research, 2002. 87(1-3): p. 1-28.
2. Hamilton, T. and F. Schweinsberg, [The reliability of conclusions based on hair mineral analysis in individual diagnostic]. Versicherungsmedizin / herausgegeben von Verband der Lebensversicherungs-Unternehmen e.V. und Verband der Privaten Krankenversicherung e.V, 2004. 56(3): p. 136-140.
3. Hambidge, K.M., Hair analyses: worthless for vitamins, limited for minerals. The American Journal of Clinical Nutrition, 1982. 36(5): p. 943-9.
4. Lowe, N.M., K. Fekete, and T. Decsi, Methods of assessment of zinc status in humans: a systematic review. The American Journal of Clinical Nutrition, 2009.
5. Rimland, B. and G.E. Larson, Hair Mineral Analysis and Behavior: An Analysis of 51 Studies. Journal of Learning Disabilities, 1983. 16(5): p. 279-285.
6. Marlowe, M., et al., Hair Mineral Content as a Predictor of Learning Disabilities. Journal of Learning Disabilities, 1984. 17(7): p. 418-421.
7. Struempler, R.E., G.E. Larson, and B. Rimland, Hair Mineral Analysis and Disruptive Behavior in Clinically Normal Young Men. Journal of Learning Disabilities, 1985. 18(10): p. 609-612.
8. Cromwell, P.F., et al., HAIR MINERAL ANALYSIS: BIOCHEMICAL IMBALANCES AND VIOLENT CRIMINAL BEHAVIOR. Psychological Reports, 1989. 64(1): p. 259-266.
9. Marlowe, M., H.G. Schneider, and L.B. Bliss, Hair mineral analysis in emotionally disturbed and violence prone children. International Journal of Biosocial & Medical Research, 1991.
10. Katz, S.A. and R.B. Katz, Use of hair analysis for evaluating mercury intoxication of the human body: A review. Journal of Applied Toxicology, 1992. 12(2): p. 79-84.
11. Blaurock-Busch, E., et al., Toxic Metals and Essential Elements in Hair and Severity of Symptoms among Children with Autism. Mædica, 2012. 7(1): p. 38-48.
12. Yasuda, H., et al., Mineral Imbalance in Children with Autistic Disorders. Biomedical Research on Trace Elements, 2005. 16(4): p. 285-292.
13. Yasuda, H., Y. Yasuda, and T. Tsutsui, Estimation of autistic children by metallomics analysis. Scientific reports, 2013. 3.
14. Yasuda, H., et al., Metallomics study using hair mineral analysis and multiple logistic regression analysis: relationship between cancer and minerals. Environmental Health and Preventive Medicine, 2009. 14(5): p. 261-266.
15. Komatsu, F., et al., A High Accumulation of Hair Minerals in Mongolian People: 2nd Report; Influence of Manganese, Iron, Lead, Cadmium and Aluminum to Oxidative Stress, Parkinsonism and Arthritis. Current Aging Science, 2011. 4(1): p. 42-56.
16. Kim, Y.-S., et al., Women with Fibromyalgia Have Lower Levels of Calcium, Magnesium, Iron and Manganese in Hair Mineral Analysis. J Korean Med Sci, 2011. 26(10): p. 1253-1257.
17. Barrett, S., Commercial hair analysis. Science or scam? JAMA, 1985. 254(8): p. 1041-5.
18. Seidel, S., et al., ASsessment of commercial laboratories performing hair mineral analysis. JAMA, 2001. 285(1): p. 67-72.
19. Drasch, G. and G. Roider, Assessment of hair mineral analysis commercially offered in Germany. Journal of Trace Elements in Medicine and Biology, 2002. 16(1): p. 27-31.
20. Namkoong, S., et al., Reliability on Intra-Laboratory and Inter-Laboratory Data of Hair Mineral Analysis Comparing with Blood Analysis. Ann Dermatol, 2013. 25(1): p. 67-72.
21. Rodrigues, J.L., et al., Evaluation of the use of human hair for biomonitoring the deficiency of essential and exposure to toxic elements. Science of The Total Environment, 2008. 405(1–3): p. 370-376.
22. Niggemann, B. and C. Grüber, Unproven diagnostic procedures in IgE-mediated allergic diseases. Allergy, 2004. 59(8): p. 806-808.
23. Sethi, T.J., et al., How reliable are commercial allergy tests? Lancet, 1987. 1(8524): p. 92-4.
24. Muramatsu, Y. and R.M. Parr, Concentrations of some trace elements in hair, liver and kidney from autopsy subjects — relationship between hair and internal organs. Science of The Total Environment, 1988. 76(1): p. 29-40.
25. Manson, P. and S. Zlotkin, Hair analysis--a critical review. Can Med Assoc J, 1985. 133(3): p. 186-8.
26. Mikulewicz, M., et al., Reference values of elements in human hair: A systematic review. Environmental Toxicology and Pharmacology, 2013. 36(3): p. 1077-1086.
27. Morley, N. and R.P.K. Ford, Hair-element analysis — still on the fringe. Child: Care, Health and Development, 2002. 28: p. 31-34.