Osteoarthritis (OA) is a chronic arthritis disease characterised by pain and stiffness of the joints caused by progressive erosion of articular cartilage, bone remodelling, new bone formation and synovial inflammation (1). The most commonly affected joints are the knees, hands and hips although it can occur to any joint. The condition affects more than 1.9 million Australians. Hip replacements due to OA accounts for nearly 50% of the OA economic cost in Australia (2).
There is no cure for OA but evidence shows that avocado and soybean unsaponifiables (ASU) may be an effective treatment for OA symptoms as it has potent chondroprotective, anabolic, anticatabolic and anti-inflammatory properties. ASUs clinically reduces joint pain and stiffness while helping improve joint function. It also actively prevents further OA symptoms. Natural remedies such as ASU have been reported to be safer for reducing OA symptoms than prescription drugs which are known to have adverse side effects. It also inhibits cholesterol absorption and endogenous cholesterol biosynthesis (3).
Avocado and soybean unsaponifiables (ASU) is a vegetable extract made up of one-third avocado oil and two-thirds soybean oil. The ASU mixture contains polyols (15%), sterols (4% - 20%), long-chain saturated hydrocarbons (5%), squalene (4%), saturated hydrocarbons (1%), and aliphatic alcohols (<1%) (1). The ASU preparation method involves cold-pressing avocado and soybean crude oils at below 50°C and extracting the unsaponifiable lipids through saponification, extraction and purification. At 20°C, ASU is a water-insoluble, oily thick paste (1).
Clinical Trials
At least six randomised, double-blind studies have been conducted on ASU's efficacy over three and six months. The trials have shown positive results for reducing symptoms of hip and knee OA. A 3 year double-blind, placebo-controlled trial tested avocado soybean unsaponifiable-Expanscience's (ASU-E) efficacy in slowing hip OA progression. Researchers concluded that 3-year treatment with ASU-E reduces the percentage of joint space width progressors, which suggests ASU-E possibly has a structure modifying effect in hip OA (2).
Description of clinical studies (5)
| Study | No. of patients Inclusion criteria | Groups of treatment and concomitant treatments | Main endpoints |
| 1 | N = 164
Age: 45-80 |
- ASU 300mg/day
- Placebo For 3 months. |
Osteoarthritis of the hip |
| 2 | N = 164
Age: 45-75 | - PIASCLEDINE 300mg/day - Placebo For 6 months then 2 months follow-up. | Osteoarthritis of the hip |
| 3 | N = 260
Age: 45-80 | - ASU 300mg/day
- ASU 600mg/day - Placebo For 3 months. | Uni or bilateral femorotibial osteoarthritis |
| 4 | N = 182
Age > 45 | - ASU - Placebo For 6 months. | Femorotibial osteoarthritis |
| 5 | N = 187
Age > 45 | - ASU - Placebo For 6 months. | Upper polar osteoarthritis of the hip |
| 6 | N = 128
Age: 45 – 80 | - ASU - Diacerein For 3 months. | Femorotibial osteoarthritis |
Avocado and soybean unsaponifiables (ASU) is a vegetable extract made up of one-third avocado oil and two-third soybean oil.
How ASU works
ASU's mechanism of action involves increasing collagen in tissues, increasing tissue lipids, and significantly increasing the proportion of extractable constituents. ASU as a whole has more powerful synergistic effects than each of its individual components (1).
ASU is believed to prevent OA osteoblast-induced inhibition of matrix molecule production, which suggests that the compound may support OA cartilage repair by acting on subchondral bone osteoblasts (4). Osteoblasts are large cells responsible for forming new bones and synthesising the collagen matrix to increase bone strength.
ASU's chondroprotective, anabolic and anti-catabolic properties suppress the breakdown of cartilage and promote cartilage repair by inhibiting the molecules and pathways implicated in OA (3).
As studies have demonstrated, ASU is an effective alternate for alleviating pain and stiffness caused by OA without the safety issues often attached to prescription medicine. Its natural, slow-acting agent not only addresses acute pain associated with OA but also helps prevent further OA symptoms.
Possible ASU combinations include Cat's Claw, ginger, vitamin C, vitamin E and manganese.
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Reference List
1.Salehi B, Rescigno A, Dettori T, et al. Avocado-Soybean Unsaponifiables: A Panoply of Potentialities to Be Exploited. Biomolecules. 2020;10(1):130. doi:10.3390/biom10010130
2.Maheu E, Cadet C, Marty M, et al. Randomised, controlled trial of avocado-soybean unsaponifiable (Piascledine) effect on structure modification in hip osteoarthritis: the ERADIAS study. Ann Rheum Dis. 2014;73(2):376-384. doi:10.1136/annrheumdis-2012-202485
3.Christiansen BA, Bhatti S, Goudarzi R, Emami S. Management of Osteoarthritis with Avocado/Soybean Unsaponifiables. Cartilage. 2015;6(1):30-44. doi:10.1177/1947603514554992
4.Christensen R, Bartels EM, Astrup A, Bliddal H. Symptomatic efficacy of avocado-soybean unsaponifiables (ASU) in osteoarthritis (OA) patients: a meta-analysis of randomized controlled trials. Osteoarthritis Cartilage. 2008 Apr;16(4):399-408. doi: 10.1016/j.joca.2007.10.003. Epub 2007 Nov 26. PMID: 18042410.
5.Haute Autorité de Santé, Avocado oil unsaponifiables, soya-bean oil unsaponifiables, 2009 Nov.