How Can Hyaluronic Acid Help Treat Osteoarthritis?
Hyaluronic acid (HA) is a naturally occurring mucopolysaccharide. It is also sometimes referred to as hyaluronate or hyaluronan. This gel-like molecule is found throughout the neural, epithelial and connective tissues of mammals. It acts primarily as cushioning and hydrating agent, with a high water absorption capacity.
An average 70kg person has approximately 15 grams of HA within the body; around one third of which is degraded and synthesized daily. However, as the body ages, HA production declines and by the mid-40s the synthesis of this polysaccharide is approximately half that required by the body.
Found naturally within the cartilage and synovial fluid of the joints, HA helps with lubrication. However, as the availability of HA decreases with age, so too does the lubrication. This can cause inflammation and result in stiff, sore joints.
There has been a lot of research investigating the effect of HA on patients suffering from osteoarthritis. Due to the important joint cushioning characteristics of HA, it’s been theorized that increasing the availability of this molecule may help to minimize joint pain and stiffness associated with osteoarthritis.
Can Intra-articular Injection of Hyaluronic Acid Reduce Osteoarthritis Symptoms?
In 2004 Wang and colleagues conducted a meta-analysis of randomised controlled trials investigating the therapeutic effects of HA on knee osteoarthritis1.The authors assessed twenty blind, randomized trials that examined the treatment of osteoarthritis using either an intra-articular injection of a placebo or hyaluronic acid. Patients were assessed based on a classification of pain without activities, pain with activities, and function.
Wang and associates concluded that an intra-articular injection of hyaluronic acid can assist in the reduction of osteoarthritis symptoms of the knee. Significant improvements were reported in pain levels and functionality, with few adverse side effects. However, the authors did acknowledge that better designed randomized controlled trials using high methodological quality were necessary to confirm these findings. More recent studies have also concluded that HA injections can help to reduce osteoarthritis symptoms2 3 4.
A recent meta-analysis argues that intra-articular injection of hyaluronic acid can be just as effective as non-steroidal anti-inflammatory drugs (NSAIDs), but without the negative side effects5.
Oral Hyaluronic Acid Administration and Osteoarthritis
Although intra-articular HA injections can help to reduce osteoarthritis symptoms there is a minor risk of infection. Researchers have been investigating the efficiency of taking hyaluronic acid orally to treat arthritic symptoms.
In a recent study, scientists randomly assigned either a placebo or 200 mg of HA daily for 12 months to sixty patients suffering from knee osteoarthritis6. During the study, all patients also participated in daily quadriceps strengthening exercises.
Each participant had their symptoms evaluated using the Japanese Knee Osteoarthritis Measure (JKMO). Patients taking oral HA daily showed more obvious improvements compared with the placebo group, especially for subjects under the age of 70. Tashiro and colleagues concluded that a daily oral intake of HA can reduce symptoms of knee osteoarthritis in conjunction with quadriceps strengthening exercises.
There is a significant body of research that supports the use of hyaluronic acid in the treatment of osteoarthritis, especially in association with knee joints. Early research has focused on intra-articular injection of hyaluronic acid and achieved positive results.
The scientific focus is now shifting towards oral administration of HA in the aim to achieve the same level of relief as injecting this important mucopolysaccharide. The advantage of using hyaluronic acid to minimise osteoarthritis symptoms is that it doesn’t present the same side effects as NSAIDs. This make HA more suitable for long-term therapeutic use.
- “Wang, C. et.al. (2004). Therapeutic effects of hyaluronic acid on osteoarthritis of the knee. A meta-analysis of randomized controlled trials. Journal of Bone and Joint Surgery. American Version. Volume 86-A, Issue 3, (pp, 538-45).” ↩
- “Juni, P. et.al. (2007). Efficacy and safety of intraarticula hylan or hyaluronic acids for osteoarthritis of the knee: a randomized controlled trial. Arthristis Rheum, Volume 56, Issue 11, (pp. 3610-9).” ↩
- “Chou, C. et.al (2008). Effect of intra-articular injection of hyaluronic acid in rheumatoid arthritis patients with knee osteoarthritis. Journal of Chinese Medication Assoication, Volume 71, Issue 8, (pp. 411-5).” ↩
- “Rogue, V. et.al. (2013). Managing knee osteoarthritis: efficacy of hyaluronic acid injections. Acta Reynatol Port, Volume 38, Issue 3, (pp. 15461).” ↩
- “Bannuru, R. et.al. (2014). Relative efficacy of hyaluronic acid in comparison with NSAIDs for knee osteoarthritis: A systematic review and meta-analysis. Seminars in arthritis and rheumatism. Volume 43, Issue 5, (pp. 593-599).” ↩
- “Tashiro, T. et.al. (2012). Oral administration of polymer hyaluronic acid alleviates symptoms of knee osteoarthritis: A double-blind, placebo-controlled study over a 12-month period. The Scientific World Journal, Volume 2012, PMC3512263.” ↩