Tobacco smoking seriously affects internal organs, particularly the heart and lungs, but it also affects a person’s appearance. While these changes are generally not as life threatening as heart and lung disease, they can, nevertheless, increase the risk of more serious disorders and have a noticeable ageing effect on the body.
Smoking and skin
The skin is affected by tobacco smoke in at least two ways. Firstly, tobacco smoke released into the environment has a drying effect on the skin’s surface. Secondly, because smoking restricts blood vessels, it reduces the amount of blood flowing to the skin, thus depleting the skin of oxygen and essential nutrients.
Some research suggests that smoking may reduce the body’s store of Vitamin A, which provides protection against some skin-damaging agents produced by smoking. Another likely explanation is that squinting in response to the irritating nature of the smoke, and the puckering of the mouth when drawing on a cigarette causes wrinkling around the eyes and mouth.
Skin damaged by smoke has a greyish, wasted appearance. Research has shown that the skin-ageing effects of smoking may be due to increased production of an enzyme that breaks down collagen in the skin. Collagen is the main structural protein of the skin which maintains elasticity. The more a person smokes, the greater the risk of premature wrinkling. Darkening of the skin around the eyes is also a possible effect of smoking.
Smokers in their 40s often have as many facial wrinkles as non-smokers in their 60s. In addition to facial wrinkling, smokers may develop hollow cheeks through repeated sucking on cigarettes: this is particularly noticeable in under-weight smokers and can cause smokers to look gaunt. A South Korean study of smokers, non-smokers and ex-smokers aged 20 to 69 found that the current smokers had a higher degree of facial wrinkling than non-smokers and ex-smokers. Past smokers who smoked heavily at a younger age, revealed less facial wrinkling than current smokers.
Smoking and Psoriasis
Compared with non-smokers, smokers have a two to threefold higher risk of developing psoriasis, a chronic skin condition which, while not life-threatening, can be extremely uncomfortable and disfiguring. Some studies have found a dose-response association of smoking and psoriasis, i.e. the risk of the disease increases the longer a person continues to smoke. Smoking also appears to be more strongly associated with psoriasis among women than among men. Smoking may cause as many as one quarter of all psoriasis cases and may also contribute to as many as half of the cases of palmoplantar pustulosis, a skin disease involving the hands and feet, that some experts view as a form of psoriasis.
Smoking and weight
When people stop smoking, they usually put on weight. Although this is often a cause for concern, the average weight gain is around 2 to 3 kg and may be temporary. Although the reasons for weight gain are not fully understood, it has been partly explained by the fact that smoking increases the body’s metabolic rate – i.e. the rate at which calories are burned up. In addition, nicotine may act as an appetite suppressant so that when smokers quit an increase in appetite leads to an increase in calorie intake. The effect of nicotine on metabolic rate may also explain why smokers tend to weigh less than nonsmokers.
Experts believe that one way smoking raises metabolic rate is by stimulating the nervous system to produce catecholamines, (hormones which cause the heart to beat faster), thus making the body burn more calories. Nicotine also produces more thermogenesis, the process by which the body produces heat. This too, causes the body to use up more calories. Women and girls tend to be more concerned about their weight and body shape than men, and weight control may be influential in causing the higher incidence of smoking among teenage girls. However, post-cessation weight gain can be modified by eating a low-fat, calorie-reduced diet and by moderately increased exercise.
While weight gain is common immediately after stopping smoking, in the longer term, ex-smokers weight may return to the comparative weight of someone who has never smoked. The combination of excess weight and smoking has also been shown to accelerate the ageing process of the body. A study showed that being both overweight and a smoker can age a person by ten years or more.
Although smokers tend to be thinner than non-smokers, the effect of smoking on the endocrine system (glands which secrete hormones) causes smokers to store even normal amounts of body fat in an abnormal distribution. Smokers are more likely to store fat around the waist and upper torso, rather than around the hips. This means smokers are more likely to have a higher waist-to-hip ratio (WHR) than non-smokers. A high WHR is associated with a much higher risk of developing diabetes, heart disease, high blood pressure, gallbladder problems and (in women) cancer of the womb and breast.
In one study of nearly 12,000 pre- and postmenopausal women aged 40 to 73, the waist to hip ratio increased as the number of cigarettes smoked per day increased. A study of American men also found a dose-response relationship between the number of cigarettes smoked and waist-to-hip ratio.
However, changes to WHR induced by smoking need not be permanent. A Swedish study examined the effect of smoking and smoking cessation on the distribution of fat in a representative sample of women. The study found that women who stopped smoking experienced less upper-body fat deposition than would be expected by their accompanying weight gain. This suggests that while some weight gain after stopping smoking can be expected, it is less of a health risk because it is not deposited in the upper torso, where it is associated with increased risk of heart disease.