Avocado Soy Unsaponifiables (ASU) are a mixture of one-third avocado oil and two-thirds soybean oil extracts. These unsaponifiable fractions have been studied particularly in the context of osteoarthritis and cartilage health. Several randomized controlled trials and systematic reviews have evaluated the efficacy of ASU in slowing the progression of cartilage damage and alleviating symptoms in osteoarthritis patients, especially of the hip and knee.

Mechanistically, ASU appears to exert anti-inflammatory effects, inhibit the synthesis of pro-inflammatory cytokines, and stimulate the production of collagen and proteoglycans in chondrocytes, which are essential components of healthy cartilage. The most commonly cited product, Piascledine, has been investigated in several clinical studies. Some of these studies have reported modest improvements in pain and function, as well as a possible reduction in joint space narrowing, which is a marker of cartilage degradation.

However, the overall quality of evidence is moderate. While some trials and meta-analyses demonstrate statistically significant benefits compared to placebo, the clinical significance of these findings remains a topic of debate, and there is variability in study design and outcomes. Major rheumatology guidelines consider ASU as a symptomatic slow-acting drug for osteoarthritis ("SYSADOA"), but do not universally recommend its use due to variability in efficacy. In summary, there is scientific evidence supporting the use of ASU for cartilage damage, but it is not robust or universally accepted.