Effects of shampoo and water washing on hair cortisol concentrations

Neuroscience and Behavior Graduate Program, University of Massachusetts, Amherst, MA 01003-9271, USA.
Clinica chimica acta; international journal of clinical chemistry (Impact Factor: 2.82). 10/2010; 412(3-4):382-5. DOI: 10.1016/j.cca.2010.10.019
Source: PubMed


Measurement of cortisol in hair is an emerging biomarker for chronic stress in human and nonhuman primates. Currently unknown, however, is the extent of potential cortisol loss from hair that has been repeatedly exposed to shampoo and/or water.
Pooled hair samples from 20 rhesus monkeys were subjected to five treatment conditions: 10, 20, or 30 shampoo washes, 20 water-only washes, or a no-wash control. For each wash, hair was exposed to a dilute shampoo solution or tap water for 45 s, rinsed 4 times with tap water, and rapidly dried. Samples were then processed for cortisol extraction and analysis using previously published methods.
Hair cortisol levels were significantly reduced by washing, with an inverse relationship between number of shampoo washes and the cortisol concentration. This effect was mainly due to water exposure, as cortisol levels following 20 water-only washes were similar to those following 20 shampoo treatments.
Repeated exposure to water with or without shampoo appears to leach cortisol from hair, yielding values that underestimate the amount of chronic hormone deposition within the shaft. Collecting samples proximal to the scalp and obtaining hair washing frequency data may be valuable when conducting human hair cortisol studies.

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    • "How the external environment impacts hair cortisol content is not well studied, and there are inconsistent reports on this subject in the literature. Repeated hair-washings in hot water and shampoo have been reported to decrease hair cortisol content by some, and this could perhaps be due to damage of the hair structure (Stout et al. 2007; Hamel et al. 2011; Li et al. 2012). Conversely, Kirschbaum et al. (2009), Manenschijn et al. (2011), and Stalder et al. (2012) found no significant differences in hair cortisol content in hair related to frequency of hair-washing or treatment. "
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    ABSTRACT: Stress is known to contribute to overall health status. Many individuals in sub-Saharan Africa are believed to be stressed about their employment, income, and health. This study aimed to investigate hair cortisol as a biomarker of chronic stress in settlement communities in Kenya. Hair samples were collected from 108 volunteers from settlement communities in Kenya. An enzyme-linked immunosorbent assay technique was used to measure hair cortisol concentrations. In parallel, a health survey was completed. The mean ± SD for the cortisol concentration in the hair of volunteers from the settlement communities in Naivasha was 639 ± 300 ng/g, which was higher than found for a Caucasian reference group (299 ± 110 ng/g; one-way ANOVA, P = 0.0003). There were no differences in hair cortisol concentrations between members of slum settlements adjacent to large floriculture farms in Naivasha (Karagita, Kamere/Kwa Muhia/DCK, and Kasarani) compared with those well-removed from all floriculture in Mogotio (Mogotio and Westlands/Katorongot). However, hair cortisol concentrations were significantly higher in females, divorced volunteers, those who made below minimum wage, and those who reported feeling unsafe collecting water or using sanitation facilities within these 2 settlement groups. We found no evidence for increased chronic stress (measured by hair cortisol content) between members of slum settlements adjacent to versus distant to large floriculture farms. Cultural and socio-economic conditions that prevail in much of sub-Saharan Africa were found to be factors contributing to chronic stress.
    Canadian Journal of Physiology and Pharmacology 07/2014; 92(9):1-8. DOI:10.1139/cjpp-2014-0035 · 1.77 Impact Factor
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    • "Thus, the systematic decrease in cortisol along the hair shaft seen in humans ('washout effect'; e.g., Kirschbaum et al., 2009) should not be observed. Hamel et al. (2011) have shown a decrease in HCC in the hair of rhesus macaques after numerous intense wash/dry procedures using shampoo or water only. Zoo-living animals , however, are not subject to frequent rain and thus a washout effect is unlikely to affect hair of captive animals. "
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    ABSTRACT: This study examined whether the method of hair cortisol analysis is applicable to orang-utans (Pongo spp.) and can help to advance the objective monitoring of stress in non-human primates. Specifically, we examined whether fundamental prerequisites for hair cortisol analysis are given in orang-utans and, subsequently, whether segmental hair analysis may provide a retrospective calendar of long-term cortisol levels. For this, hair samples were examined from 71 zoo-living orang-utans (38 males, 33 females, mean age = 23.5 years) for which detailed records of past living conditions were available. Hair samples were cut from defined body regions and were analyzed either in full length or in segments. Results showed that hair cortisol concentrations (HCC) were unrelated to age or sex of the individual animal. HCC were found to be higher in orang-utans, with perceived long-term stressful periods (mean HCC = 43.6 ± 26.5 pg/mg, n = 13) compared to animals without perceived stressful periods (19.3 ± 5.5 pg/mg, n = 55, P < 0.001). In non-stressed animals, segmental hair analyses revealed that HCC was stable along the hair shaft even when hair reached >40 cm. The possibility of obtaining a retrospective calendar of stress-related cortisol changes through hair analysis was further supported by data of three case studies showing close correspondence between the segmental HCC results and keeper reports of stress exposure during the respective time periods. Finally, low within-animal variation in HCC from different body regions (CV%: 14.3) suggested that this method may also be applicable to naturally shed hair, e.g., as found in nests of wild orang-utans and other great apes. Therefore, using HCC may provide an ideal non-invasive tool for both captive management as well as conservation in orang-utans and potentially other great apes.
    General and Comparative Endocrinology 11/2013; 195. DOI:10.1016/j.ygcen.2013.11.002 · 2.47 Impact Factor
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    • "repeated washing of hair might leach some of the cortisol from within the hair shaft causing cortisol lev - els to decline significantly as a function of the distance from the scalp . We recently confirmed this hypothesis using monkey hair samples treated with differing num - bers of washes with a standard commercially available shampoo solution ( Hamel et al . , 2011 ) . Importantly , a con - trol condition in which hair samples were washed with tap water alone showed nearly the same amount of cor - tisol loss . Thus , any comparison of cortisol concentrations between free - ranging / corral housed and laboratory housed primates might be confounded by exposure to rainfall , especially if such rainfa"
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