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The consequences of smoking on hair health

Smoking impacts both health, the condition of the skin, and that of the hair. Indeed, tobacco consumption triggers numerous detrimental effects on the hair. Discover in this article the consequences of smoking on the hair fibre.

Summary
Published May 7, 2024, by Kahina, Scientific Editor — 4 min read
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Consequence No.1: Smoking accelerates hair loss.

Tony H. H. CHEN and Lin-Hui SU aimed to evaluate the association of androgenetic alopecia (AGA) with smoking and estimate its prevalence among Asian men, by conducting a survey based on questionnaires. Significant positive associations were observed between moderate or severe alopecia and smoking status with a relative risk of 1.77, current smoking of 20 or more cigarettes per day with a relative risk of 2.34, and the intensity of smoking with a relative risk of 1.78. Therefore, smoking tobacco would indeed be associated with hair loss.

The mechanisms by which smoking causes hair loss are multifactorial. Firstly, the skin's micro-circulation is constricted by both acute and long-term smoking. Consequently, cells may not receive sufficient oxygen and nutrients, which can lead to hair loss.

Furthermore, the genotoxic compounds in smoke can damage the DNA of the hair follicle. Indeed, the reduction of capillary blood flow in the dermal papilla of hair follicles can also concentrate more toxic substances. Nicotine and cotinine are both detected in hair samples from smokers, and mutations in mitochondrial DNA associated with smoking have been observed in human hair follicles. These mutations can damage the follicles, leading to hair loss.

Finally, smoking can lead to oxidative stress. It induces the production of free radicals, which cause lipid peroxidation (or degradation), and subsequently triggers the apoptosis of hair follicle cells by upregulating genes related to this process. This could therefore be one of the reasons why hair loss can be observed. Oxidative stress can also lead to the release of pro-inflammatory cytokines which, in turn, cause a micro-inflammation and follicular fibrosis.

Consequence No. 2: Smoking can lead to the onset of grey hair.

Yousef AL-MOTASSEM and his team wanted to determine whether there is a significant link between greying of hair prematurely and smoking. An observational study was conducted on 207 participants. The participants were classified into two groups: premature greying and normal greying. Premature greying was defined as the first appearance of grey hair before the age of 30.

Data on smoking and hair greying were collected using a questionnaire. The prevalence of smokers in the premature group was higher: 40.2% compared to 24.7%. Smokers began to grey earlier, specifically 31 smokers compared to 34 non-smokers. Overall, smokers were two and a half times more likely to develop premature hair greying than non-smokers.

The colour of hair primarily depends on the presence or absence of melanin pigments produced by melanocytes. As previously mentioned, it has been suggested that smoking could be associated with the production of large amounts of reactive oxygen species leading to increased oxidative stress. This pro-oxidant effect of smoking could damage the melanocytes and thus reduce the synthesis of melanin, resulting in white or grey hair. This theory is supported by the observation that the melanocytes in the hair follicles of grey hair are often highly vacuolated, a common response to increased oxidative stress.

Sources

  • TRÜEB R. M. Association between smoking and hair loss: Another opportunity for health education against smoking? Dermatology (2003).

  • SU L. H. & al. Association of androgenetic alopecia With smoking and its prevalence among Asian men: A community-based survey. Archives of Dermatological Research (2007).

  • AL-MOTASSEM Y. & al. Smokers’ hair: Does smoking cause premature hair graying? Indian Dermatology Online Journal (2013).

  • TRÜEB R. M. Effect of ultraviolet radiation, smoking and nutrition on hair. Practical Evaluation and Management (2015).

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