ANN ARBOR, MICH. — A new study conducted by researchers at the University of Michigan Medical School suggests a link may exist between cigarette smoking and higher levels of aging on areas of skin not normally exposed to sunlight. The study, reported in the March issue of Archives of Dermatology, was headed by Yolanda R. Helfrich, M.D., assistant professor of dermatology at the University of Michigan Medical School. Previous studies have found that cigarette smoking contributes to premature skin aging as measured by facial wrinkles, the new study says, but little data has been accumulated to measure the aging of skin not exposed to light.
COVERED BUT STILL AGING "We examined nonfacial skin that was protected from the sun and found that the total number of packs of cigarettes smoked per day and the total years a person has smoked were linked with the amount of skin damage a person experienced," Dr. Helfrich says in a statement released by the University of Michigan Medical School. "In participants older than 65 years, smokers had significantly more fine wrinkling than nonsmokers. Similar findings were seen in participants aged 45 to 65 years."
The researchers tested 82 people, ages 22 to 91, half of whom were smokers, and photographed their inner right arms. Three independent judges were assigned to determine the extent of wrinkling on each participant's skin by assigning a grade based on applying a photonumeric scale the research team developed. The scale, on which zero indicated no fine wrinkling and 8 indicated severe fine wrinkling, was based on information compiled from the photographs. The same judges reviewed photos of the participants one year later, and the scores were used to determine the level of increase in the skin damage.Researchers also gathered participant information including age, ethnicity, history of cigarette smoking, use of nonsteroidal anti-inflammatory drugs, dietary or herbal supplements, sun exposure, sunscreen use and tanning-bed use. Women participants were also asked the number of children they had borne and about hormone therapy and oral-contraceptive use.
BLOOD FLOW SUSPECTED Among the participants who were current or former cigarette smokers, the average length of time they indulged in smoking was 24 years. In the 45-to 65-year age group, smokers had an average score on the photonumeric scale of more than 2, while nonsmokers scored less than 1, on average. In the 65 and older age group, smokers had an average score of about 6, while nonsmokers had an average score of approximately 4. The report did not discuss the mechanism involved that produces a higher degree of skin aging in smokers, but previous research has concluded that cigarette smoke causes subcutaneous blood vessels to constrict, which in turn reduces blood supply to the skin. Other previous research has found that smoking also damages the connective tissue that supports both the skin and the internal organs.
Helfrich YR, Yu L, Ofori A, et al. Effect of smoking on aging of photoprotected skin: evidence gathered using a new photonumeric scale. Arch Dermatol. 2007;143:397-402.