LONDON -- If the increased risk of lung cancer and heart disease isn't enough to convince smokers to quit, Japanese scientists have a new incentive -- it causes wrinkles.
Akimichi Morita and researchers at Nagoya City University Medical School have shown how smoking could upset the body's mechanism for breaking down old skin and renewing it."Dermatologists say the finding confirms the long-held view that smoking ages skin prematurely," New Scientist magazine said Wednesday.
Morita and his colleagues demonstrated the link in the laboratory by exposing human skin cells that produce collagen -- connective tissue that makes up around 80 percent of normal skin -- to a solution of cigarette smoke and saline.
Before the body can make new skin, it must break down the old skin with special enzymes called matrix-metalloproteinases, or MMPs, that destroy the fibers that form collagen.
After the skin cells were exposed to the smoke solution for a day, the scientists tested them for MMP and new collagen. The cells produced much more MMP than normal skin cells but about 40 percent less new collagen.
Morita and his team believe the combined rapid breakdown of collagen and the lack of new collagen is probably what causes premature aging in smokers.
"This suggests the amount of collagen is important for skin aging," said Morita. "It looks like less collagen means more wrinkle formation."
The researchers hope to confirm their laboratory findings by testing the effects of smoking on skin samples from smokers and non-smokers in different age groups.
"So far we've only done this in the lab," Morita told the magazine.
Lawrence Parish, director of the Center for International Dermatology in Philadelphia, said the research confirms that tobacco smoke is injurious to skin.