Various species of yucca plant were used as food by Native Americans and early California settlers. Yucca contains high levels of soapy compounds known as saponins that also made it a useful natural shampoo and soap.
One double-blind placebo-controlled trial reported in 1975 concluded that use of yucca reduces arthritis symptoms (both osteo- and rheumatoid arthritis).1 However, this study was highly preliminary in nature, and there has not been any subsequent confirming evidence.
Animal and test tube studies suggest that various yucca extracts may have antiviral, antifungal, antiprotozoal (e.g., Giardia) and antibacterial effects,3-6 but no human trials have been reported for potential uses based on these actions.
Yucca extracts are also widely used to enhance the foaming effect of carbonated beverages.
The standard dosage is 2 to 4 tablets of concentrated yucca saponins daily.
Yucca is generally accepted as safe based on its long history of use as a food. However, it sometimes causes diarrhea if taken to excess. Safety in young children, pregnant or nursing women, or those with severe liver or kidney disease has not been established. Yucca may have slight estrogen-like actions,2 and for this reason should not be taken by women who have had breast cancer.
1. Bingham R, Bellew BA, Bellew JG. Yucca plant saponin in the management of arthritis. J Appl Nutr. 1975;27:45–51.
2. Zava DT, Dollbaum CM, Blen M. Estrogen and progestin bioactivity of foods, herbs and spices. Proc Soc Exp Biol Med. 1998;217:369–378.
3. Miyakoshi M, Tamura Y, Masuda H,et al. Antiyeast steroidal saponins from Yucca schidigera (Mohave yucca), a new anti-food-deteriorating agent. J Nat Prod. 2000 Mar;63(3):332-338.
4. Wang Y, McAllister TA, Yanke LJ, Cheeke PR. Effect of steroidal saponin from Yucca schidigera extract on ruminal microbes. J Appl Microbiol. 2000 May;88(5):887-896.
5. McAllister TA, Annett CB, Cockwill CL, et al. Studies on the use of Yucca schidigera to control giardiosis. Vet Parasitol. 2001 May 22;97(2):85-99.
6. Hayashi K, Nishino H, Niwayama S, et al. Yucca leaf protein (YLP) stops the protein synthesis in HSV-infected cells and inhibits virus replication. Antiviral Res. 1992 Apr;17(4):323-333.
Last reviewed December 2015 by EBSCO CAM Review Board Last Updated: 12/15/2015