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What do we need to know about hair straightening?

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Abstract

p class="abstract"> Hair straightening is a popular hair procedure. The first hair straightening products were used for African hair. Various modes of hair straightening methods are currently being used. Temporary methods like blow drying and ironing are used for easy manageability of hair, both by modern men and women. Salon- based hair straighteners were initially permanent relaxers which, with time, evolved to formaldehyde-free hair strengthening procedures like hair Botox which is currently in trend. It improves hair manageability, increases hair strength and reduces frizz without producing much chemical damage to hair and by maintaining their natural waves, thereby producing a more natural look. We performed a thorough literature search on the topic in PubMed, consulted various hair stylists and beauty school professors prior to formulation of this article. The article aims at understanding the basic mechanisms involved in various hair straightening methods which helps us to advice patients on a wholesome care of hair. </p

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Cosmetic hair care products are often implicated by the user or the clinician in cases of hair loss. Yet, these products are used ad lib, in a wide variety of home conditions and on a wide variety of hair types, by millions of consumers every day with no adverse effects. Based on this extensive data set, the absence of literature reports, and a detailed understanding of the mode of action of cosmetic hair care products, we can conclude that they do not cause hair loss. Clinicians investigating cases of hair loss must fully appreciate the hair cycle, the length of time a single fibre may be present on the head, and its biological and cosmetic history in order to understand the causes of hair loss and make the correct diagnosis. With a better understanding of the cosmetic practices used by everyday consumers, the clinician will be in a strong position to help patients re-grow their hair and guide them through a high quality hair care regime.
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Hair relaxers (straighteners) have been used by millions of African American women, often for many years. Relaxer ingredients can enter the body through scalp lesions and burns. Because manufacturers are not required to list all ingredients, these products may contain unknown harmful substances. We assessed hair relaxer use in relation to breast cancer incidence in the Black Women's Health Study, a nationwide follow-up study of African American women. Information on hair relaxer use was collected in 1997; 48,167 women were followed subsequently through 2003 for incident breast cancer. Incidence rate ratios of breast cancer were estimated with Cox regression. During 266,298 person-years of follow-up, 574 incident cases of breast cancer were ascertained. There were no increases in breast cancer risk associated with any categories of duration of hair relaxer use, frequency of use, age at first use, number of burns experienced during use, or type of relaxer used. The incidence rate ratio for use at least seven times a year for 20 or more years relative to use for less than a year was 0.98 (95% confidence interval, 0.78-1.39). These results suggest that hair relaxer use does not increase the incidence of breast cancer in African American women.
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Glyoxylic acid, a small dicarboxylic acid, has been detected at measurable levels in the atmosphere and is suspected to be present in indoor air environments. It is generated through the ozonolysis of several high volume production compounds that are commonly found indoors. Glyoxylic acid was tested in a combined irritancy and local lymph node assay (LLNA). It tested positive in the LLNA with an EC3 value of 5.05%. Significant increases were observed in the B220+cell population in the draining lymph nodes. No changes were identified in the IgE+B220+ cell population in the draining lymph nodes or total serum IgE levels; this suggests that glyoxylic acid functions as a T-cell-mediated contact sensitizer. Exposure to volatile organic compounds (VOC), similar to glyoxylic acid, emitted from building materials, cleaning formulations or other consumer products, and /or indoor chemistry have been linked to adverse health effects. These results may provide an explanation for some of adverse health effects associated with indoor air exposure.
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To evaluate the genotoxic risk to hairdressers exposed daily to chemical substances such as hair dyes, waving and straightening preparations and manicurists' products by the Comet assay test (single-cell gel electrophoresis). The Comet assay was performed on blood samples from 69 female hairdressers (36.4 +/- 10.7 years old) currently employed in 21 different beauty institutes in São Paulo, Brazil, and on 55 female control blood donors (32.6 +/- 10.0 years old) from the São Paulo University Clinical Hospital blood bank. All the control subjects had occupations other than hairdresser. Comet assays were performed by evaluating 100 blood lymphocytes per individual and graded by visual score according to comet tail length. The hairdressers showed a higher frequency of DNA damage revealed by Comet Score (159.8 +/- 71) when compared to the control group (125.4 +/- 64.1), and the difference was statistically significant by the Student's t-test (P = 0.005). Multiple regression analysis showed that in addition to the hairdressers' profession, tobacco use contributed to the higher frequency of cells with comets (P < 0.05). The observed DNA damage could be associated with the hairdressers' occupational environment, where different chemicals are chronically manipulated and inhaled. Considering that this profession in many countries, including Brazil, is not officially regulated, more attention should focus on these professionals not only by legislative bodies but also by multidisciplinary teams able to develop and implement risk prevention and control strategies for chemical, physical and biological agents to which hairdressers are exposed.
Impact of acid straightener's pH value in the hair fiber properties
  • A M Goshiyama
  • M F Dario
  • Crrc Lima
  • Glb De Araújo
  • A R Baby
  • Mvr Velasco
Goshiyama AM, Dario MF, Lima CRRC, de Araújo GLB, Baby AR, Velasco MVR. Impact of acid straightener's pH value in the hair fiber properties. J Cosmet Dermatol. 2020;19(2):508-13.