Hyaluronic acid 101
Hyaluronic acid (HA) is the naturally occurring and widespread component found within the extracellular matrix (ECM) and bodily tissues, especially those of the face. Its water-binding and water-attracting attributes fill up the spaces between the connective fibers of collagen and elastin in the dermis. The skin’s dermis layer is made up of about 70 percent water and claims nearly 50 percent of your body’s total HA allotment. Hyaluronic acid decreases with age and adults have only 1/20 the HA of a baby — hence the excitement over topical solutions for potentially replenishing it.
What role does HA play in aging skin?
Wrinkles come about from the loss of three important components in the skin: collagen, hyaluronic acid and elastin. HA provides the hydrating, nutrient-transporting framework necessary for holding up the structure of the ECM in the skin. If elastin is not bathed in water it becomes dry and brittle, invariably leading to dull, loose and less-elastic skin. Bottom line: Dry skin is aged skin.
What is sodium hyaluronate?
Sodium hyaluronate has a smaller molecular size than HA, making it especially penetrative, and is able to hold more water than any other natural substance — up to 1,000 times its weight in water. So how is it sourced for our face creams? Originally extracted from rooster combs, it is now produced as a reactive byproduct of benign bacteria and is identical to the substance found within the skin.
Topical hyaluronic can reach deep down into the dermis to combine with, maintain and attract water. It also promotes microcirculation and nutrient absorption and helps maintain normal metabolism. The Journal of Clinical and Aesthetic Dermatology published a study that found that hyaluronic acid can “boost skin’s moisture content, reduce inflammation, have cell-communicating abilities and help prevent moisture loss.”
But there may be more to it than hydration. One study, in Germany, measured the effect of hydrolyzed hyaluronic acid on gene expression. It was found that hydrolyzed hyaluronic acid changed the regulation of more than 40 genes, including those responsible for cell to cell adhesion. The researchers concluded that hyaluronic acid improves skin tautness.
True or false: The molecules are too big to penetrate the skin
These days there are methods to reduce the molecular size and increase the likelihood of penetration. Furthermore, a 1999 study on animals and humans found that even large molecules will penetrate deep into the epidermis, the dermis and the lymphatic endothelium.
What about those high concentration claims? Sodium hyaluronate typically makes up 1 to 2 percent of a solution, which is primarily comprised of water. Claims of 10 percent SH and even 75 percent SH are simply misleading. In any case, high concentrations would act as a sponge and simply draw out moisture from the skin, thus causing dryness. All the responsible formulators that I have spoken to say it just isn’t possible to formulate with over 2 percent sodium hyaluronate.
The dry climate controversy
You may have heard that in dry climates hyaluronic acid may actually make your skin drier. The theory goes that in dry climates, where there’s little moisture in the air, HA may resort to tapping the skin’s own moisture resources, bringing them to the surface to evaporate. The result is drier skin. Now I haven’t found any research that definitively proves this, but anecdotally I have heard from members of the Truth In Aging community that live in desert climates who have reported that HA makes their skin appear parched. In this case, it could be a good idea to ensure that the formula also contains occlusive ingredients that can lock water into the skin.
Alternative forms of hydration
Tremella fuciformis is a genus of fungi in the family tremellacea that has water-retention capabilities that are supposedly superior to hyaluronic acid. Not only is the jelly-like fungi a source of vitamin D, but it’s also a free radical scavenger that enhances the body's own superoxide dismutase. According to one study, it even inhibits melanin. The study found that when the polysaccharide was isolated from a hot water extract of a Tremella mushroom without adding a chemical agent, it actually inhibited melanin formation with an inhibition ratio of 59.7 percent. You can find tremella fuciformis in products by Sevani.
Even with the sodium hyaluronate family, there are different chemical subsets. For example, Deciem, in its Hyalmide SubQ, hedges its bets with three variations: sodium hyaluronate crosspolymer, hydrolyzed sodium hyaluronate and sodium hyaluronate. It goes even further with Deciem NIOD Multi-Molecular Hyaluronic Complex, taking a multi-dimensional approach to hydrating that features no less than 12 different hyaluronic compounds.