快猫短视频

SMOKING causes wrinkles by upsetting the body鈥檚 mechanism for renewing skin,
say scientists in Japan. Dermatologists say the finding confirms the long-held
view that smoking ages skin prematurely.

Skin stays healthy and young-looking because of a fine balance between two
processes that are constantly at work. The first breaks down old skin while the
second makes new skin. The body breaks down the old skin with enzymes called
matrix metalloproteinases, or MMPs. They chop up the fibres that form
collagen鈥攖he connective tissue that makes up around 80 per cent of normal
skin.

Akimichi Morita and his colleagues at Nagoya City University Medical School
suspected that smoking disrupted the body鈥檚 natural process of breaking down old
skin and renewing it. To test their idea, they first made a solution of
cigarette smoke by pumping smoke through a saline solution. Smoke was sucked
from cigarettes for two seconds every minute. Tiny drops of this smoke solution
were added to dishes of human fibroblasts, the skin cells that produce
collagen.

After a day in contact with smoke solution, the researchers tested the skin
cells to see how much collagen-degrading MMP they were making. Morita found that
cells exposed to cigarette smoke had produced far more MMP than normal skin
cells.

Morita also tested the skin cells to see how much new collagen they were
producing. He found that the smoke caused a drop in the production of fresh
collagen by up to 40 per cent.

He says that this combined effect of degrading collagen more rapidly and
producing less new collagen is probably what causes premature skin ageing in
smokers. In both cases, the more concentrated the smoke solution the greater the
effect on collagen. 鈥淭his suggests the amount of collagen is important for skin
ageing,鈥� he says. 鈥淚t looks like less collagen means more wrinkle
蹿辞谤尘补迟颈辞苍.鈥�

Morita doesn鈥檛 know if this is the whole story of why smokers have more
wrinkles. But he plans to confirm his findings by testing skin samples from
smokers and non-smokers of various ages to see if the smoking has the same
effect on collagen. 鈥淪o far we鈥檝e only done this in the lab,鈥� he says. 鈥淲e don鈥檛
know exactly what happens in the body yet鈥攖hat might take some time.鈥�

Other dermatologists are impressed by the work. 鈥淭his is fascinating,鈥� says
Lawrence Parish, director of the Centre for International Dermatology at Thomas
Jefferson University Hospital in Philadelphia. This confirms scientifically what
we鈥檝e long expected, he says. 鈥淭obacco smoke is injurious to skin.鈥�