What Are Avocado Soybean Unsaponifiables?
Avocado soybean unsaponifiables (often referred to as ASU) are a natural vegetable extract made from avocado and soybean oils. As a dietary supplement, avocado soybean unsaponifiables have been shown in clinical studies to have beneficial effects on osteoarthritis.
What Have Studies Shown About Avocado Soybean Unsaponifiables?
Natural remedies are popular with arthritis patients. Most people believe that natural products are safer than prescription medications. The implication being that there are less undesirable side effects with natural products. But does ASU work? What does the research say?
So far, there have been 4 studies that assessed the effect of avocado soybean unsaponifiables on knee osteoarthritis and hip osteoarthritis. Two of the studies were conducted over 3 months -- one assessed hip and knee osteoarthritis, while the other looked only at knee osteoarthritis. Results from both studies revealed that patients who took 300 mg of avocado soybean unsaponifiables a day didn't need as much pain medication as before -- they decreased their use of NSAIDs (nonsteroidal anti-inflammatory drugs). There was no significant difference observed between the 300 and 600 mg once a day dose of avocado soybean unsaponifiables.
In the third trial, a 6-month trial that evaluated avocado soybean unsaponifiables on hip and knee osteoarthritis, 300 mg once a day improved the Lequesne Functional Index compared to placebo.
A 2-year clinical trial on hip osteoarthritis revealed that 300 mg once a day of avocado soybean unsaponifiables did not slow down joint space narrowing and no other significant differences were observed when compared to placebo after one year. A later analysis of the study, however, determined that avocado soybean unsaponifiables might decrease joint space narrowing in patients with very severe hip osteoarthritis.
How Quickly Does It Work?
Avocado soybean unsaponifiables took at least two months before any improvement was noticed, according to the study results. Interestingly, there also was residual symptom relief for 2 months after stopping treatment.
Wherever it is available as a supplement, a 300 mg softgel daily is what is recommended to treat osteoarthritis. Eating avocado and soy, even in large amounts, will not provide enough of the unsaponifiables to provide a benefit for osteoarthritis. Only a small fraction of the oil is the unsaponifiable portion.
The Future for Avocado Soybean Unsaponifiables
Long-term studies have not yielded positive results -- some think that's because researchers looked at the effect of avocado soybean saponifiables on joint structure rather than focusing on symptom relief. More long-term studies are needed.
Regarding safety, there was no significant difference in adverse effects between avocado soybean unsaponifiables and placebo in any of the 4 studies.
In France, avocado soybean unsaponifiables are available with a prescription. The French have tracked its safety for 15 years and there appears to be no significant problems.
Avocado Soybean Unsaponifiables (ASU). Arthritis Today Supplement Guide. Arthritis Foundation. 7/16/2007.
Osteoarthritis and nutrition. From nutraceuticals to functional foods: a systematic review of the scientific evidence. Laurent G Ameye and Winnie SS Chee. Arthritis Research and Therapy. 2006; 8(4): R127.