Found in skin, eyes, cartilage and joints, hyaluronic acid acts as both a structural support and as a lubricant. Many companies sell hyaluronic acid nutritional supplements claiming to help rebuild cartilage and relieve arthritis symptoms. However, large molecules such as hyaluronic acid are quickly broken down during digestion making oral supplements useless. Ophthalmic and plastic surgeons, however, find injectable forms of hyaluronic acid beneficial, building up lost tissue and relieving joint pain.
Chemistry
Polysaccharides are long strings of sugar molecules used for either storing energy or providing structural support for cells and tissues. Hyaluronic acid, short for hyaline uronic acid, is a specific type of polysaccharide called glucosaminoglycan. Composed of long chains of disaccharides or two-sugar subunits, hyaluronic acid contains two modified glucose molecules; an N-acetyl-glucosamine linked to glucuronic acid. Hyaluronic acid may contain several thousand sugar molecule subunits linked together. Short hyaluronic acid chains provide lubricating properties, while larger chains appear gelatinous.
Effects
Hyaluronic acid has anti-inflammatory and pain-relieving properties. Injections may help stimulate your body to produce more hyaluronic acid yourself. Relief of joint pain with hyaluronic acid injections are not immediate. However, many patients do begin to feel benefits after the third round of treatment. The pain relief may last for several months. Immediate effects of hyaluronic acid injections can include pain, warmth and slight swelling at the injection site, but these effects most likely relate to the injection itself, rather than the hyaluronic acid.
Functions
Hyaluronic acid protects cartilage by providing increased lubrication between joint surfaces . When challenged by weight-bearing activities, the hyaluronic acid helps act as a shock absorber. Conditions such as arthritis show decreased hyaluronic acid in joint space, which can lead to damage during joint use by compression or sheer stress forces. Hyaluronic acid also helps increase the flow of nutrition to cartilage by impeding larger proteins often associated with inflammation, blocking pain receptors as well.
