Tobacco and skin: the misconceptions.

No. Theimpact of smoking goes beyond our lungs. Studies have proven the harmful effects of smoking on the skin:

• It induces oxidative stress that accelerates the skin ageing process by degrading dermal fibres through the synthesis of free radicals;

• It makes the complexion dull due to a reduction in oxygen transport in the blood, which impacts cellular renewal;

• It can cause skin cancers through gene mutation;

• It impairs the healing process;

• It increases the risk of developing psoriasis due to the free radicals produced;

• It has been associated with the onset of acne.

Furthermore, smoking can also affect our hair. Tobacco promotes hair loss and leads to the emergence of grey hair.

Yes and no. It's important to understand that after quitting smoking, certain aspects of your skin will improve. Indeed, Kohei TAKAHASHI and his team demonstrated in a study that ceasing smoking for four weeks could enhance skin clarity and reduce redness, by lowering the level of haemoglobin in the blood.

However, another study, conducted by Finn GOTTRUP and his colleagues, concluded that the impairment of healing capacity caused by smoking could be long-lasting, if not irreversible. Parameters such as transepidermal water loss, which is high for smokers and should decrease during normal healing, showed no significant difference between current smokers and former smokers, particularly in terms of the temporal evolution of this measure.

However, these are only hypotheses, highlighting the need for additional studies.

Yes. In 2009, Mauro PICARDO and his team demonstrated a correlation between the frequency of non-inflammatory acne and smoking. Smoking appears to increase oxidative stress and thus generate free radicals, and decrease levels of vitamin E in the plasma, which is the main antioxidant transported by sebum to the skin's surface to maintain a low rate of lipid peroxidation in the sebaceous glands, such as squalene. When its peroxide is produced, it exerts a hyper-proliferative effect on keratinocytes, which will clog the pores and therefore be comedogenic. In this way, smoking can cause the onset of acne.

No. This idea is quite widespread, due to the fact that many skin-related consequences of smoking have been perceived as dose-dependent in relation to the quantity of cigarettes smoked. However, several studies have reported significant effects on the skin from light smoking.

For instance, Enrico Maria PROCACCINI and his colleagues found that smoking just one cigarette could affect the skin's microcirculation by reducing blood flow. This will then impact cellular renewal. A build-up of dead cells on the skin will be observed, followed by a dulling of the complexion.

No. Passive smoking, that is, the involuntary inhalation of smoke emitted by one or more smokers, can also have harmful effects on the skin. Indeed, tobacco smoke alone contains approximately 1,017 free radicals per puff, which if inhaled, can cause skin damage by oxidising dermal fibres such as collagen and elastin, thereby accelerating skin ageing. This will also induce the secretion of pro-inflammatory cytokines like IL-12, which consequently leads to the onset of inflammatory conditions such as psoriasis.

This smoke also contains toxic compounds, such as nitrosamines, phenolic compounds, and aromatic amines. These substances can cause DNA mutations and lead to skin cancers. Finally, it contains nicotine, carbon monoxide, and hydrogen cyanide, which interfere with the processes involved in wound repair and thus will impact healing.

• PROCACCINI E. M. & al. The acute effect of smoking on cutaneous microcirculation blood flow in habitual smokers and nonsmokers. Dermatology (1998).

• GOTTRUP F. & al. Effect of smoking, abstention, and nicotine patch on epidermal healing and collagenase in skin transudate. Wound Repair and Regeneration (2009).

• PICARDO M. & al. Acne and smoking. Dermato-Endocrinology (2009).

• TAKAHASHI K. & al. Improvement in skin color achieved by smoking cessation. International Journal of Cosmetic Science (2012).