Amanda Sandford, research manager for Action on Smoking and Health (ASH), said she hoped this would act as a warning, particularly to young smokers.
They claim that simply looking at a person's face could show whether he or she is a smoker.
A study by dermatologists, published in The Lancet, shows that smoking activates the genes responsible for a skin enzyme that breaks down collagen in the skin.
Collagen is the main structural protein of the skin and keeps it elasticated.
When this starts to disintegrate, skin begins to sag and wrinkle.
Professor Antony Young and his colleagues from Guys, Kings and St Thomas' School of Medicine, in London, measured concentrations of the gene MMP-1, which breaks down collagen.
Wrinkly skin
They studied the buttock skin of 14 smokers and 14 non-smokers and found significantly more MMP-1 genetic material in the skin of smokers.
Professor Young said: "Smoking exerts such a noticeable effect on the skin that it's often possible to detect whether or not a person is a smoker simply by looking at his or her face.
"Smokers have more wrinkles and their skin tends to have a greyish pallor compared to non-smokers.
"Smoking tobacco activates this enzyme that breaks down the skin collagen.
"We did not know that before, we suspected it from studies done in the test-tube, but this is the first proof."
Professor Young also warned of the dangers of solar ultra-violet radiation, which has a particularly detrimental effect on the skin of the face.
Amanda Sandford, research manager for Action on Smoking and Health (ASH), said she hoped this would act as a warning, particularly to young smokers.
"It's ironic that teenagers often start smoking in the hope of appearing more mature but it probably never occurs to them by middle-age they will really start to look older than their age.
"For smokers, middle-age starts in their early 30s as the tell-tale wrinkles around the mouth and eyes begin to appear.
"Young female smokers are likely to be wasting money on anti-ageing face creams if they continue to smoke.
"The best beauty treatment by far is to quit smoking."
The Tobacco Manufacturers Association criticised the study saying it was too small and inconclusive.
A spokesman said: "This latest piece of research is too small in sample to be of real significance.
"The investigators themselves use the words 'might' and 'possibly' in their conclusions and admit that sun's rays could be an important factor."