ANN ARBOR, Mich. — Fine wrinkles, deeper creases, saggy areas around
the mouth and neck – the sights in the mirror that make baby boomers
wince – are not inevitable. They result from a structural breakdown
inside the skin that some existing treatments effectively counteract by
stimulating the growth of new, youthful collagen, University of
Michigan scientists say.
The researchers report an emerging
picture of collagen collapse and possible renewal, based on more than a
decade of studies, in the May issue of Archives of Dermatology.
article draws on dozens of studies since the early 1990s, conducted
primarily by U-M dermatologists, to explain why three types of
available skin treatments are effective: topical retinoic acid, carbon
dioxide laser resurfacing and injections of cross-linked hyaluronic
These treatments all improve the skin’s appearance –
and its ability to resist bruises and tears – by stimulating new
collagen. Collagen is a key supporting substance, plentiful in young
skin, that’s produced in the sub-surface layer of skin known as the
dermis. The U-M findings show that the breakdown of the dermis’ firm,
youthful structure is a very important factor in skin aging – a much
more straightforward thing to fix than genetic factors that others
theorize may be involved.
“Fibroblasts are not genetically
shot,” says John J. Voorhees, M.D., F.R.C.P., chair of the Department
of Dermatology at the U-M Medical School and the article’s senior
author. Fibroblast cells in the skin are the key producers of collagen.
“We have shown that if you make more collagen go in, it
provides an environment in which fibroblasts recover and make more
Voorhees and co-authors Gary J. Fisher, Ph.D., U-M
professor of dermatology, and James Varani, Ph.D., U-M professor of
microbiology and immunology and of pathology, hope the findings will
help people make intelligent decisions amid the hype of the
multi-billion-dollar anti-aging products industry. Fisher directs the
U-M Photoaging and Aging Research Program.
“We want to educate
clinicians about what’s been found, and what it means in terms of how
we may improve the appearance of people,” says Voorhees, the Duncan and
Ella Poth Distinguished Professor of Dermatology at U-M.
Young vs. old skin
formation and breakdown takes place in the dermis or inner skin – the
thicker, firm layer of skin that lies beneath the paper-thin outer skin
or epidermis, much as a mattress lies beneath a sheet. Collagen
consists of proteins that make up a supporting structure surrounding
the skin cells. In youthful skin, collagen is firm, taut and abundant,
like a new mattress. In older skin, the collagen structure begins to
fall away, says Voorhees.
Just as a foam mattress over time
becomes flatter in places and creased as its structure breaks down,
aging skin begins to sag and wrinkle when its collagen is diminished
and fragmented. The cycle of events involved in collagen loss is
As skin ages, reactive oxygen species,
associated with many aspects of aging, lead to increased production of
the enzyme collagenase, which breaks down collagen. Then fibroblasts,
the critical players in firm, healthy skin, lose their normal stretched
state. They collapse, and then more breakdown enzymes are produced.
People in their 80s have four times more broken collagen than people in
“What it’s doing is dissolving your skin,”
Voorhees says. “What you’ve got is a vicious cycle. You have to
interrupt it, or aging skin is just going downhill.”
elderly, in whom the dermis has lost two-thirds or more of its youthful
thickness through collagen loss, skin tears and bruises easily.
Collagen-building interventions thus have potential for reducing basic
health problems such as bed sores, in addition to improving appearance.
A growing body of evidence
U-M researchers base their conclusions on past studies in which they
have explored why certain anti-aging treatments are effective. A 2007
study looked at Restylane, marketed as a dermal filler, and found that
injections of the product caused fibroblasts to stretch, promoting new
collagen, and also limited the breakdown of collagen.
another 2007 study, the U-M team tested lotions containing retinol, a
form of Vitamin A found in many skin-care products, and found it
significantly reduced wrinkles and skin roughness in elderly skin by
promoting new collagen. Other U-M studies have shown why some laser
treatments work and some less powerful ones do not. Carbon dioxide
laser resurfacing is effective because it removes the aging dermis; in
the three-week regrowth process, new, young collagen is produced.
and his colleagues say they provide needed, independent research on the
effectiveness of available and future treatments to counteract skin
aging. They have no ties to the manufacturers of products they study.