Reversing damage in the skin from aging and the sun is the holy grail of skin care. For decades, the focus has been on slowing the aging process, but so much more is possible when applying already-known information from studies and experience. There are three categories for antiaging skin care ingredients recommended for sun damaged skin: prevention, plumping, and wound repair. This article will review why some ingredients do more than others and discuss the most important targets needed to activate repair within the skin.

The aging process involves a combination of factors that impact the skin. There is no question that free radical damage is the primary reason sun exposure is so hard on the skin. It damages DNA, cell walls, and other structural components within the epidermis and dermis. Additionally, the skin loses approximately 1% of its circulation each year after age 25, which results in the loss of critical skin nutrients that force a slowdown in collagen manufacturing, epidermal turnover, and wound repair – to name a few. The analogy would be going on a crash diet that causes the body to slow down its metabolism and cellular activity. This means a typical 50-year-old will have 25% less circulation and food, 25% less dermal collagen, 25% fewer growth factors, 25% slower turnover (making it a 38-day epidermal cycle), and 25% less capacity to heal wounds. The looming question is: can professionals do anything about this? Can professionals increase circulation and create new capillaries to feed the skin? What critical ingredients are missing to accelerate wound repair? Can free radical damage be corrected or should professionals simply stay focused on preventing more damage?

The reality of today’s instant gratification world is that formulators look for a good marketing story along with the visible improvement of fine lines within three to six weeks. As long as those two boxes are checked, they are not very interested in how the improvement occurs or what, if anything, can make the skin reverse damage more permanently. The following is a list of the main ingredient strategies used:

• antioxidants
• vitamin C
• vitamin A
• alpha hydroxy acids
• peptides and growth factors

DO ANTIOXIDANTS MAKE SKIN YOUNGER?
Are topically applied antioxidants (vitamins A and C discussed later) an important part of the prevention of aging? No. The skin is intelligent enough that every time it sends oxygen towards the surface, it is accompanied by an antioxidant bodyguard. This means that with minimal time in the sun and the avoidance of oxidizing topical ingredients, most people are adequately protected. Even though there are 25% fewer antioxidants at age 50, there is also 25% less oxygen that can be radicalized. Excess daily sun or the use of retinols, alpha hydroxy acids, and peroxide may justify the addition of antioxidants to a client’s regimen. However, antioxidants generally do not stimulate collagen or repair oxidative damage, so their role is quite limited. The bottom line is that on a tier of the most important strategies to repair sun damage, antioxidants rank relatively low.

WHAT IS THE BEST VITAMIN C FOR THE SKIN?
Vitamin C is another major storyline that has persisted for decades but often remains misunderstood. Most people think L-ascorbic acid is an antioxidant story and the focus has been on novel ways to prevent its oxidation before it is applied to the skin. If that were really the story, then those suffering with scurvy (inadequate vitamin C in the skin) would simply age faster. In reality, scurvy means the skin falls apart, so what is vitamin C’s most important role? It is one of the most important molecules in the skin because, through its role in the hydroxylation of amino acids, it makes them capable of binding to each other to make collagen and elastin and facilitates wound healing. Another misconception is that this invaluable molecule is one and done in its role. In other words, people commonly assume that oxidized vitamin C is useless or harmful. This is far from the truth. It actually lasts about two weeks in the skin with half of an individual’s daily application disappearing within four days. Why does it stay around? It is recycled by the antioxidant glutathione and used again and again by the skin. For discussion purposes, let us say that L-ascorbic acid gets oxidized and recycled 100 times in that two-week period. This means that oxidized vitamin C still has 99 more uses even if it oxidizes in the bottle before application. The other concern for this molecule is absorption; topical vitamin C does not penetrate well and adding stabilizers to prevent oxidation results in even worse absorption rates. There is also confusing research that suggests a pH of 3.5 or lower is needed to improve penetration but this study involves 24 hours under an occlusive dressing (not a typical skin care application), so what they really determined was that professionals can improve vitamin C penetration if they destabilize the barrier with prolonged, intense acid exposure. Lowering pH to enhance penetration has long been shown to be ineffective in improving absorption in normal applications. How do we make sense of the data? Trust what it says. The best form of vitamin C is the smallest, because each application has the best chance of delivering more to the dermis. Research shows that oxidized vitamin C has better penetration, so one could argue that it is the preferred topical form because it is still 99 percent viable. Every stabilized version of vitamin C penetrates less effectively because of the added bulk. To make things worse, C-esters, like ascorbyl palmitate and tetrahexyldecyl ascorbate, are not even bioavailable because the skin cannot detach the ester. The summary of this information is that vitamin C’s most bioavailable form is L-ascorbic acid and its oxidized counterpart dehydroascorbic acid because they have the best chance of penetrating to the dermis and being fully utilized over 100 recycling events.

ARE ALL VITAMIN A’S EQUAL?
It is universally accepted that vitamin A is an essential part of good skin care, but where did that come from? Research shows that the skin stores several forms of vitamin A but relies heavily on retinoic acid as the fibroblast activator for collagen manufacturing. Do we know the roles of other forms of vitamin A? Not really. Does the research support that more vitamin A is needed topically? Not really. The dilemma is that vitamin A can be quite damaging to the epidermis, so the pros and cons of each form have to be weighed. To start, retinoic acid is research-proven to thin the dermis by 18% if used daily for one year. It is research-proven to cause severe damage to the integrity of the epidermis, including skin DNA. The skin’s best collagen stimulator is not meant to have a significant presence in the epidermis – or even the dermis, for that matter. Its manufacturing is highly controlled since it cannot be stored in the skin; thus, retinoic acid is made from stored retinaldehyde on an as-needed basis. Pushing it through the epidermis creates a lot of damage on the way down and then distorts normal maintenance of the dermis because there are too many molecules to manage. It may surprise skin care professionals to know that retinol and retinyl palmitate also cause DNA damage when they oxidize in the epidermis. Professionals talk about the sun sensitizing effects of retinol and many people follow the practice of only using vitamin A at night, but the reality is that their nightly application is still present in the epidermis the next day, so DNA damage is unavoidable. The keratolytic effect of retinols is known to increase ultraviolet damage and dehydrate the skin and is present 24 hours a day, even if only applied at night. So, what is the right answer? The only other vitamin A besides retinoic acid that is proven to stimulate collagen at a high level, one thousand times more than every other retinol, is retinaldehyde. Stabilized retinaldehyde has the added benefit of not oxidizing and not being highly keratolytic, thus minimizing the potential for DNA damage, dehydration, and sun sensitivity. Its presence is proven to activate the conversion to retinoic acid when applied topically, but on the skin’s timeline, so it is rarely more than the skin can handle. Once the issue of sun sensitization is removed, twice daily micro-doses around 0.1% make sense to maximize the potential of fibroblasts. A delivery system like liposomes is preferable because of the known absorption problems of such a large molecule. Every other form of vitamin A ages the skin and should be avoided because all of the research on these retinols shows they only thicken the epidermis temporarily.

SHOULD YOU SAY “NO WAY” TO AHAs?
Common sense says that if the skin is burned, it will respond by repairing the burned collagen with new collagen. There will likely be an uptick in collagen production right after the burn. This is not a rejuvenation event. This is one more burden added to the skin’s many repair projects. Replacing the skin’s critical maintenance activities with new onset wound repair logically means that less collagen can be made for the dermis, as more collagen is being made for the epidermal wound. This reality is why alpha hydroxy acids have failed to demonstrate any antiaging advantage other than swelling the skin. Why do clients love the burn of acids? It makes their skin plump and feel tight. That is a combination of inflammation (which is never a win in the battle against aging) and the melting away of the protective lipid barrier – which, when combined, temporarily tighten the skin and give a false sense of rejuvenation. Alpha hydroxy acids are proven to increase ultraviolet damage and to dehydrate the skin when used above 5% at a pH below 5. There is no research showing they make the skin younger in the process.

GROWTH FACTORS, CYTOKINES, AND PEPTIDES … OH MY!
There is no question that the most talked about ingredient class for the last several years has been peptides. They have some exciting marketing stories and petri dish results. Where they fall short is in-vivo (on real skin) studies. There are very few peptides that show the ability to change real skin significantly. The larger peptides and many of the smaller ones often end up as protein fragments trapped in the epidermis. The good news is that it can result in a plumping effect that improves the appearance of fine lines. The bad news is that they do not activate repair in deeper layers and, thus, do very little to improve the health and vitality of the skin. Growth factors and cytokines (signal proteins) made from human stem cells have a better track record in clinical trials, even though they are larger molecules. They activate receptors in the follicles. They are a critical part of encouraging new blood vessel formation to rejuvenate the skin but, since that comes with certain risks, growth factors may not be unless they have been proven safe on cancer cells. For example, epidermal growth factor (EGF) used by itself accelerates cancer cells. One has to wonder if any of these peptide or growth factor serums have similar potential but, thus far, those tests are not being mandated. Growth factors signal the skin to increase repair and rejuvenation efforts as long as they are stable – a common issue with all peptides. Look for formulas that have exosomes, which are protective shells that surround the proteins while also serving to enhance bioavailability. Finally, when choosing a peptide or growth factor serum, look at their clinical data. Do not accept in-vitro results as fact and always look at the company’s laboratory data because growth factors are measurable and any company not providing those measurables for comparison has something to hide.

The skin is capable of restoring a lot of its losses if skin care professionals show it kindness by limiting exfoliation and certain retinols and acids and feed it the necessary ingredients to maximize its potential. Stabilized, liposomal retinaldehyde is proven to accelerate collagen activation without harming the skin. L-ascorbic acid is the smallest and most bioavailable form of vitamin C, followed by oxidized vitamin C, and both are a necessary part of a daily regimen. Make sure every element of protocols for aging and sun damage is targeted and purposeful. Prevention strategies are a lower priority than wound repair, although limiting excessive sun exposure is a must. Temporarily plumping the skin without increasing inflammation is fine, as long as it does not replace those ingredients that make real change in the skin. This is skin care’s new paradigm and it should give skin care professionals hope.

Ben Johnson, MD, is the founder and formulator of Osmosis Skincare. He is a graduate of Creighton University School of Medicine, an entrepreneur, an inventor, and an outside-the box thinker. Johnson spent most of his career in aesthetic medicine beginning with a chain of medical spas, but developing innovative skin care that is changing the industry is his passion. His holistic approach incorporates highly effective, revolutionary strategies that treat skin conditions at their source, providing permanent results.