Avocado and Soybean Print Page


Common Names: avocado, alligator pear, soy, soybean, ASU

Scientific Names: avocado (Persea americana), soybean (Glycine max)

 Bottom Line

Effectiveness: Avocado/soybean unsaponifiable oil (ASU) may modestly improve pain and functionality in knee and hip OA.

Safety: Likely safe when used orally at appropriate doses for up to six months.  Long term safety unknown.

What are avocado and soybean?

  • Avocado is a dark green berry fruit with a single large seed native to Mexico and Central America.
  • Soybean is a legume plant native to East Asia. Its beans are used to make tofu, soy milk, and soy based foods.
  • Both avocado and soybean are high in nutrients.

What are they used for in people with rheumatic conditions?

  • Combination of avocado and soybean unsaponifiable (ASU) oils may be beneficial in the management of osteoarthritis (OA).

How is it thought to work?

  • Some studies suggest that avocado/soybean oils can increase collagen growth, reduce joint space narrowing, and reduce the production of substances that increase inflammation (inflammatory mediators).

Does it Work? What the Science Says:

  • Two studies demonstrated that taking ASU 300mg/day significantly reduced the dose of NSAID needed in patients with knee OA after 2 to 3 months of use
  • Another study evaluating ASU 300mg/day in knee and hip OA found ASU significantly improved pain and functionality
  • However, a longer-term study (2 years) did not show any benefit of ASU in reducing joint space loss in patients with hip OA
  • Well-conducted studies are limited
  • ASU may improve symptoms of OA and reduce NSAID use
  • May be worth trying for 4-8 weeks
  • More long term trials are needed

What are possible side effects and what can I do about them?

  • ASU is generally well tolerated when taken orally at appropriate doses. Stomach upset, nausea/vomiting, headaches, and migraine have also been reported.
  • Patients allergic to avocado and soybean should avoid ASU.
  • Allergic reactions have been reported in people with latex sensitivity ingesting avocado. Take ASU with caution.


With drugs:

  • Based on case reports, avocado and soymilk may decrease the anticoagulant effect of warfarin, which would increase the risk of a blood clot. It is unknown if ASU would show similar results. Close monitoring of INR may be needed in patients starting or stopping ASU.


To learn more, visit AlbertaRheumatology.com, & consult your physician and pharmacist.