Smoking affects not only health, but also the condition of the skin and hair. Indeed, tobacco consumption causes numerous harmful effects on the hair. Discover in this article the consequences of smoking on the hair fiber.
The consequences of smoking on hair health
- Consequence #1: Smoking accelerates hair loss
- Consequence #2: Smoking can lead to the onset of gray hair
Consequence #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 implementing a questionnaire-based survey. 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 smoking intensity with a relative risk of 1.78. Therefore, tobacco smoking would indeed be associated with hair loss.
The mechanisms by which smoking causes hair loss are multifactorial. Firstly, the skin's micro-circulation is narrowed by both acute and long-term smoking. Therefore, cells will not be sufficiently supplied with 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 theapoptosis of hair follicle cells by upregulating genes related to this process. This could 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 micro-inflammation and follicular fibrosis.
Consequence #2: Smoking can lead to the onset of gray hair.
Yousef AL-MOTASSEM and his team wanted to determine if there is a significant link between graying of hair prematurely and smoking. An observational study was conducted on 207 participants. The participants were classified into two groups: premature graying and normal graying. Premature graying was defined as the first appearance of gray hair before the age of 30.
Data on smoking and hair graying were collected using a questionnaire. The prevalence of smokers in the premature group was higher: 40.2% versus 24.7%. Smokers began to gray earlier, specifically 31 smokers compared to 34 non-smokers. Overall, smokers were two and a half times more likely to develop premature hair graying than non-smokers.
Hair color 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 melanin synthesis, resulting in white or gray hair. This theory is supported by the observation that the melanocytes in the hair follicles of gray hair are often highly vacuolated, a common response to increased oxidative stress.
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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