The major components of avocado/soybean unsaponifiables (ASU) are considered anti-inflammatory compounds
with antioxidant properties that also provide analgesia (phytosterols). This compound blocks the activation of TNF-a, IL-1b, inducible nitric oxide synthase COX-2 transcripts and secretion of prostaglandin E2.49 Among the ASU experiments for OA, four highquality RCTs were considered in the meta-analysis by Christensen et al.50 A total of 664 OA subjects with
either hip (41.4%) or knee (58.6%) OA were grouped to either 300 mg ASU (336) or placebo (328) arm for
an average trial duration of 6 months. The combined pain reduction favored ASU (P = 0.04) and the number
of responders following ASU is significantly higher compared to placebo (odds ratio [OR] 2.19, P = 0.007). These results were corroborated on a Cochrane review on herbal therapy for treating OA.
The two combined studies of ASU in this meta-analysis showed beneficial effects on functional index, pain, intake of NSAIDs and global evaluation with no serious side effects.51
49 Au RY, Al-Talib TK, Au AY, Phan PV, Frondoza CG (2007) Avocado soybean unsaponifiables (ASU) suppress TNF-alpha, IL-1beta, COX-2, iNOS gene expression, and prostaglandin E2 and nitric oxide production in articular chondrocytes and monocyte/macrophages. OsteoarthritisCartilage 15(11), 1249–55.
50 Christensen R, Bartels EM, Astrup A, Bliddal H (2008) Symptomatic efficacy of avocado-soybean unsaponifiables
(ASU) in osteoarthritis (OA) patients: a meta-analysis of randomized controlled trials. Osteoarthritis Cartilage 16(4), 399–408.
51 Little CV, Parsons T (2001) Herbal therapy for treating osteoarthritis. Cochrane Database Syst Rev (1), CD002947.
International Journal of Rheumatic Diseases 2011; 14: 152–158
