Hyaluronic acid is one of the stars of what are called nutricosmetics, an alternative for reducing skin wrinkles, they say, to more aggressive treatments like Botox. It comes in the form of injections, gels or pills that are worth their weight in gold. But does hyaluronic acid really work? What are the side effects?
Originally used as an egg substitute in baking and later to treat diseases of the connective tissues that surround and hold most internal organs in place, hyaluronic acid is a polysaccharide naturally present in our body that holds water in cells and tissues in a percentage equivalent to a thousand times its weight. This confers hyaluronic acid with an interesting redensifying and moisturizing potential that the cosmetics industry is exploiting to the full.
Healing and rejuvenating
In 2004 the ABC network in the USA attributed hyaluronic acid with almost miraculous qualities in a documentary on the long-living Japanese Yuzurihara people. Their skin remains soft and smooth and they have enviable health, all because their diet includes tubers and starches that improve the body’s synthesis of hyaluronic acid. The news spread after the documentary was broadcast and a Japanese company developed the first hyaluronic acid tablets.
First isolated by the German pharmacist Karl Meyer in 1934, hyaluronic acid has been used by the cosmetics industry since 1996. It had previously been used by athletes to speed up their recovery from sprained ankles and other joint problems.
In France, hyaluronic acid injections received publicity as a consequence of injury treatment in the tennis player Amélie Mauresmo in 2002. But despite the fact that hyaluronic acid was already used to treat osteoarthritis of the knee, the US Food and Drug Administration (FDA) did not approve it as a wrinkle treatment until 2003, when it did so for the brand Restylane (hyaluronic acid of non-animal origin) and somewhat later (2006) for other brands such as Juvederm (hyaluronic acid produced by bacterial fermentation).
Both these products are gels that are injected under the skin. Restylane claims to have administered more than 11 million treatments worldwide and states that the risk of allergy or hypersensitivity reactions from its product is minimal.
Little scientific evidence
However, despite the commercial success of these products and the fact that the above observations are corroborated by research such as that by Fabrizio Duranti and coworkers of the American Society for Dermatologic Surgery, few studies exist that demonstrate the effectiveness of hyaluronic acid in removing wrinkles. Most studies refer to the injectable form of the substance to treat knee osteoarthritis and are positive.
Few studies, however, have measured the impact of polysaccharide injections in the skin. The Journal of the American Academy of Dermatology stated in 2009 that injected wrinkle fillers, specifically hyaluronic acid, can cause skin inflammation, redness and itching.
In April 2012, a study published in Nature negatively linked hyaluronic acid to cancer. In contrast, a study by the University of Buenos Aires and the Argentine National Council of Scientific and Technical Research (CONICET) dating to May 2011 indicated that hyaluronic acid could play an important role in reversing resistance to drugs used in chemotherapy. Again, there is insufficient positive or negative evidence.
Capsules and tablets
As for oral hyaluronic acid supplements, scientists say that the formulation generally has a molecular weight too great for the body to absorb. In other words, there is evidence that the pills do not work because it is difficult to digest them, although some self-serving articles do plug their effectiveness.
Meanwhile, the cosmetics industry continues to test formulations that are more absorbable by the body and so take effect more quickly; however, it is not yet known what damage could be caused if this process is accelerated.
For the moment, cosmetic dermatologists like Leslie Baumann, associate professor of clinical dermatology and cosmetics at the University of Miami (USA), see the injections as a powerful ally for her work. Baumann says that for years dermatologists have known that wrinkles result from the loss of three crucial components of the skin: collagen, elastin and hyaluronic acid. “Today, we can replace two of these components - collagen and hyaluronic acid”. She concludes: “It is my hope that one day we will be able to replace elastin as well”.