The same destructive effects that smoking has on skin,
causing premature aging among other visible changes, also may contribute
to baldness.
Wound-healing experiments have shown that the smallest
blood vessels that supply the scalp are constricted by both acute and
long-term smoking, reports Dr. Ralph M. Trueb, a dermatologist at the
University Hospital of Zurich, in an editorial in the April issue of
Dermatology. Researchers also have detected nicotine and cotinine, a toxic
byproduct in smoke, in smokers' hair. Studies have shown that when these
substances are processed by cells in the hair follicle, mutations occur in
the cell's DNA.
Among the research Trueb cites in his editorial is
evidence that smoking causes inflammation. Experiments have shown that
pro-inflammatory proteins inhibit growth of hair follicles. These proteins
trigger the release of enzymes that cause scarring around the follicles,
which also interferes with hair growth.
Cigarette smoking also
causes a drop in estrogen, tipping the hormone balance in favor of the
male hormone androgen, which contributes to hair loss in
men.
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-- Dianne Partie Lange
