How old are you? smoking causes premature aging.
If you want to stay young, do not light up. Smokers often look old before their time, because they have many more wrinkles than nonsmokers of the same age. Dermatologists now believe they may have discovered why. A study published in March 24 issue of The Lancet suggests that smoking stimulates production of an enzyme that makes the skin less elastic.
Scientists have known for some time that both smoking and exposure to ultraviolet (UV) predispose to premature aging of the skin. A team of dermatologists led by Anthony Young of the Institute of St. John of Dermatology at Kings College London first studied how UV light affected the levels of matrix metalloproteinase-1 (MMP-1), a enzyme that chops proteins. MMPs degrade collagen, a structural protein that is important for maintaining the elasticity of the connective tissue and constitutes up to 70% of the dry weight of the skin. When collagen is destroyed, the skin begins to sag and bend
Young and his fellow volunteers divided into two groups. a group of sites on their buttocks exposed to UV light, while the other did not. Skin biopsies revealed a curious fact: The levels of MMP-1 mRNA in the controls are not normally distributed, but are divided into two distinct groups. The team was perplexed. But then Young said he remembered seeing the results of a Japanese study showing that in vitro tobacco smoke solution induces transcription of the MMP-1 gene in cells of the human skin. When the team asked if they smoked, they discovered that smokers tend to have high levels of MMP-1 mRNA. He was completely "accidental discovery," says Young. Apparently, one of the thousands of chemicals in tobacco causes the MMP-1 levels to rise.
The results are important for several reasons, says Christopher Griffiths of Dermatology Centre at the University of Manchester. "This study shows that chemicals in cigarette smoke affect the whole body," he said, not only the parties who smoke is in direct contact with. "Inhaled products are transported through the bloodstream and make contact with all organs. "Griffiths also notes that emphysema, a lung disease common among smokers, is marked by a loss of connective tissue and may be related to the increase in MMP-1.
Related Sites
St. John Institute of Dermatology
DermWeb (skin care and dermatology information)
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