Here There and Everywhere

Nostrums that promise to smooth wrinkled skin are a staple of snake-oil salesmen everywhere, but now there is strong evidence that certain kinds of treatment are effective. Over the past decade, researchers have been learning which treatments work, and why.

The key is a growing understanding of the skin’s connective tissue, called the dermal collagen, and a recognition that damage to the mechanical properties of the collagen outside the skin cells, and not necessarily genetic damage to the cells themselves, causes wrinkled skin.

A recent review in The Archives of Dermatology concludes that three anti-aging treatments are proven clinically effective: the topical application of retinol; carbon dioxide laser resurfacing; and injection of hyaluronic acid, a moisture-retaining acid that occurs naturally in the skin. Each depends on the same mechanism, the interaction of skin cells called fibroblasts with the collagen they produce.

“This is an area where there’s a lot of hype and not much substance,” said David J. Leffell, a professor of dermatology and surgery at Yale who was not involved in the review. But, he said, this study is “good science.”

Theory and experiment back these treatments, the authors write. Fibroblasts — connective tissue cells — secrete a complex group of polysaccharides and proteins that creates collagen, which gives the skin shape and elasticity and supports the blood vessels that permeate it. The network of collagen tissue is maintained by its mechanical tension with these skin cells.

Skin deteriorates as it ages, but its exposure to sunlight inhibits the ability of fibroblasts to produce collagen. The hands, face, neck and upper chest all suffer more than unexposed skin, and light-pigmented people wrinkle more readily than others. This damage, the authors write, is essentially an accelerated version of chronological aging. Ultraviolet radiation induces production of the same enzymes that degrade collagen with age.

Collagen fibers last as long as 30 years. But with age and ultraviolet exposure, they deteriorate and fragment, and fragmented collagen impairs the collagen-producing function of the fibroblasts that created it. As the fragmented collagen accumulates, new collagen production declines, the connections between the fibroblasts and the collagen weaken, and the skin, now lacking support, begins to wrinkle.