When asked what protein is the most important for maintaining youthful skin (i.e. firm, bouncy, sag-free, unwrinkled skin), the majority of people and many experts would say collagen. (Well, ok, the majority might say "No idea!" or "what's a protein?" but you know what I mean...). Indeed, collagen is important for the skin - it is the principal structural protein holding the skin together. Yet, there is another skin protein that is at least as important: elastin. Elastin is a protein found in any elastic connective tissue. It is responsible for the ability of tissues to resume original shape after being stretched.
Chemistry of elastin
Elastin is a protein primarily composed of the amino acids glycine, valine, alanine, and proline. Just as collagen, it is produced by the connective tissue cells called fibroblasts. More accurately, fibroblasts secrete tropoelastin, the soluble immature form of elastin. Tropoelastin molecules are then cross-linked in a reaction catalyzed by the enzyme lysyl oxidase, forming a durable, resilient web of elastin fibers that behaves akin to latex.
Elastin and aging
One simple test for skin aging is to check how long it takes for the skin to snap back after being pinch-pulled away. (You can try it on the back of your hand.) Young skin snaps back almost immediately. The old one takes up to several seconds. The reason for such difference is quantity and quality of elastin in the skin.
The amount of elastin in the skin usually peeks in adolescence or early adulthood and declines thereafter. Fibroblasts in older skin have a much reduced capacity to produce new elastin. This deficiency does not appear to be a result of the loss of fibroblasts or mutations in elastin-encoding genes. More likely, age-related changes in the skin's biochemical environment shut down elastin production. Therefore, at least in theory, elastin production can be restored to its youthful levels with proper biochemical signals.
Can you boost elastin in your skin?
Boosting elastin in the skin is a somewhat neglected topic in skin care. In part, this is a result of excessive focus of cosmetic industry and dermatologic research on collagen - arguably at the expense of elastin. The skin's collagen content and composition can be increased/improved by a number of topical formulas (e.g. ascorbic acid, copper peptides, etc.) as well as procedures (lasers, resurfacing and so forth). Unfortunately, much less is known about boosting the skin's elastin. Yet it is just as important for successful skin rejuvenation. Below I list a few approaches that show at least some promise to restore and/or preserve elastin levels in aging skin. However, as of the time of this writing, none is reliably proven to do so.
Retinoic acid
In a tissue culture study, retinoic acid (a.k.a. tretinoin, Retin A, Renova) was shown to increase elastin synthesis in chick embryonic vascular smooth muscle cells up to 2.8-fold. Interestingly, retinol (a form of vitamin A often touted in skin care as a better tolerated substitute for retinoic acid) had no effect on elastin synthesis in that study. There is some ground to believe that topical retinoids may also stimulate elastin synthesis in the human skin. But any definitive research to that effect is lacking. (See also our articles on tretinoin and other retinoids.)
MMP inhibitors
Skin rejuvenation is not just about producing more of the key components of the skin matrix, such as collagen and elastin. It is also about protecting the one you have from excessive degradation. Such degradation is caused primarily by the enzymes matrix metalloproteinases (MMP). There are many types of MMP and some are involved in breaking down elastin: MMP-2, MMP-9, MMP-12, and possibly others. Inhibiting these MMP may increase the skin content of elastin by reducing the rate of its degradation. (See our article on MMP inhibitors.)
Controlled tissue injury procedures
Some skin rejuvenation procedures (e.g. lasers or medium-to-deep peels) work by inducing controlled tissue injury followed by skin remodeling, which leads to increased production of new skin matrix and skin remodeling. The predominant protein produced during healing is collagen but the synthesis of elastin increases as well. However, whether such procedures lead to the sustained improvement in the density and quality of elastin in the skin remains unclear. (See our section on noninvasive procedures.)
Topical tropoelastin
As we discussed earlier, fibroblasts synthesize the immature soluble form of elastin (tropoelastin), which then permeates the dermis and fuses into an elastic web. What if tropoelastin were applied to the skin in a cream? Would that help? At least one skin care company, DermaPlus, Inc. (not affiliated with SmartSkinCare.com in any way), sells topical tropoelastin in a cream called DermaLastyl. The company claims that their products increase skin content of elastin, thereby reducing wrinkles and firming skin. Unfortunately, their research data have not been published in any peer-reviewed research journals. Furthermore, large molecules like tropoelastin generally do not penetrate into the dermis easily enough to produce clinically significant effects. Some skin penetration (all the way into the dermis) is occasionally possible even for large molecules, including certain proteins. However, the claims that topical tropoelastin restores youthful levels of dermal elastin will require solid, independent scientific evidence before they can be taken seriously.
Ethocyn
Ethocyn (ethoxyhexyl-bicyclooctanone) is a small molecule tht easily penetrates into the dermis. It is claimed to specifically increase the synthesis of elastin to the levels seen in early adulthood. At present, the evidence backing such claims appears sparse. (See our acricle on Ethocyn.)
