Written by Helen Seers, Helen Cooke and the CAM-Cancer Consortium.
Updated July 23, 2009

Laetrile

Abstract and key points

  • Laetrile is an acronym used to describe a purified, semi-synthetic form of Amygdalin, a naturally occurring plant compound.
  • There is no clear evidence that laetrile is effective as an anti-cancer agent.
  • Laetrile is associated with serious safety concerns.

Laetrile is an acronym used to describe a purified, semi-synthetic form of Amygdalin (LAEvorotatory and mandeloniTRILE). Amygdalin is a naturally occurring plant compound that contains sugar and produces cyanide and is found primarily in the kernels of apricots, peaches and bitter almonds and also in plants such as lima beans, clover and sorghum.

The main active cancer-killing ingredient of Laetrile is thought to be cyanide, this has caused serious concerns over toxicity. Laetrile is reported to be an anti-cancer treatment or even cure. It was at the height of its popularity in the 1970s and 1980s, and has since been rejected by the scientific community after a phase II controlled clinical trial in 1982 which found no evidence for the efficacy of laetrile and highlighted safety concerns.

Although there is no further clear evidence that laetrile is effective as an anti-cancer agent, a recent Cochrane review suggested that in view of recent promising laboratory studies further laboratory investigations might be considered.

Laetrile/Amygdalin/B17 is associated with potential toxic effects at certain doses (cyanide poisoning) and liver problems.

Citation Helen Seers, Helen Cooke, CAM-Cancer Consortium. Laetrile [online document]. http://www.cam-cancer.org/CAM-Summaries/Biologically-Based-Practices/Laetrile. July 23, 2009.

References

  1. Davignon, JP, Trissel, LA, & Kleinman, LM. Pharmaceutical assessment of amygdalin (Laetrile) products. Cancer Treatment Reports. 1978; 62 (1): 99-104.
  2. Chandler, RF, Phillipson, JD & Anderson, LA. Controversial Laetrile. Journal of Pharmacology. 1984; 232: 330-332.
  3. Ellison, NM, Byar, DP, & Newell, GR. Special report on Laetrile: the NCI Laetrile Review. Results of the National Cancer Institute's retrospective Laetrile analysis.New England Journal of Medicine. 1978; 7;299 (10):549-52.
  4. Beard J. The Enzyme Treatment of Cancer, 1911. London: Chatto and Windus.
  5. Krebs, ET Jr., Krebs, ET Sr., & Beard, HH. The Unitarian or trophoblastic thesis of cancer. Medical Record. 1950; 153 (7): 149-74.
  6. Conchie, J, Findlay, J, and Levvy, GA. Mammalian glucosidases: distribution in the body. Biochemical Journal. 1959; 71: 318-25.
  7. IARC Handbooks on Cancer Prevention. 2003. Vol. 8 ‘Fruit and Vegetables’ WHO.
  8. Vickers A. Alternative cancer cures; “unproven” or “disproven”?. CA: A Cancer Journal for Clinicians. 2004; 54, 110-8.
  9. Greenberg, DM. The case against Laetrile: The fraudulent cancer remedy. Cancer. 1980; 15; 45 (4) :799-807.
  10. McCarrison, SR. “Nutrition and National Health.” Journal of the Royal Society of Arts. 1936. lxxxiv, 1047, 1067, 1087.
  11. Wodinsky, I, & Swiniarski, JK. Antitumour activity of amygdalin MF (NSC-15780) as a single agent and with beta-glucosidase (NSC-128056) on a spectrum of transplantable rodent tumours. Cancer Chemotherapy Reports. 1975; 59, (5): 939-50.
  12. Overjera, AA., Houchens, DP., Barker, AD. et al. Inactivity of DL- amygdalin against human breast and colon tumor xenografts in athymic (nude mice). Cancer Treatment Reports. 1978; 62 (4): 576-78.
  13. Manner HW, DiSanti SJ, Maggio MI, et al. Amygdalin, vitamin A and enzyme induced regression of murine mammary adenocarcinomas. Journal of Manipulative Physiolgical Therapy. 1978; 1 (4): 246-8.
  14. Bhatti RA, Ablin RJ, & Guinan PD. Tumour-associated directed immunity in prostatic cancer: effect of amygdalin. IRCS Medical Science research Biochemistry. 1981; 9 (1): 19.
  15. Biaglow JE, & Durand RE. The enhanced radiation response of an in vitro tumour model by cyanide released from hydrolysed amygdalin. International Journal of Radiation Biology. 1978; 33 (4): 397-401.
  16. Syrigos KN, Rowlinson-Busza G, & Epenetos AA. In vitro cytotoxicity following specific activation of amygdalin by beta-glucosidase conjugated to a bladder cancer-associated monoclonal antibody. International Journal of Cancer. 1998; 78 (6): 712-9.
  17. Newmark J, Brady, RO, Grimley, PM, Gal, AE, Waller, SG, & Thistlethwaite, JR. Amygdalin (Laetrile) and pruasin beta-glucosidases: Distribution in germ free rat and in human tumor tissue. Proceedings of the National Academy of Sciences of the United States of America. 1981; 78 (10): 6513-6.
  18. Binzel, PE, Alive and Well, 1994. American Media Publishing, USA.
  19. Navarro, MD. Five years experience with Laetrile therapy in advanced cancer. Acta Unio Int Contr Cancrum. 1959; 15 (suppl 1): 209-21.
  20. Moertel, CG, Ames, MM, Kovach, JS, et al. A pharmacologic and toxicological study of amygdalin. Journal of the American Medical Association. 1981. 245 (6): 591-4.
  21. Moertel, CG, Fleming, TR, Rubin, J, et al. A clinical trial of amygdalin (Laetrile) in the treatment of human cancer. New England Journal of Medicine. 1982; 306 (4): 201-6.
  22. Kochi, M, Takeuchi, S, Mizutani, T, et al. Antitumor activity of benzaldehyde. Cancer Treatment Reports. 1980; 64 (1): 21-3.
  23. Kochi, M, Isono, N, Niwayama, M, et al. Antitumor activity of a benzaldehyde derivative. Cancer Treatment Reports. 1985; 69 (5): 533-7.
  24. Moss, RW. The Cancer Industry: The Classic Expose on the Cancer Establishment. (1996). Brooklyn, NY: First Equinox Press.
  25. Quackwatch topics [online]. 2004 [cited 2004 July 18]. Available from URL: http://www.quackwatch.org/01QuackeryRelatedTopics/Cancer/Laetrile.html
  26. Braico, KT, Humbert, JR, Terplan, KL, & Lehotay, JM. Laetrile intoxication: report of a fatal case, New England Journal of Medicine. 1979; 1; 300 (5): 238-40.
  27. Sadoff, L, Fuchs, K, & Hollander, J, Rapid death associated with Laetrile ingestion, Journal of the American Medical Association. 1978; 14; 239 (15): 1532.
  28. Lee, M, Berger, HW, Givre, HL, et al. Near fatal Laetrile intoxication: Complete recovery with supportive treatment, Mount Sinai Journal of Medicine. 1982; 49 (4): 305-307.
  29. Milazzo S, Ernst E, Lejeune S, Schmidt K. Laetrile treatment for cancer. Cochrane Database Syst Rev. 2006 Apr 19;(2):CD005476. Review.
  30. Milazzo S, Lejeune S, Ernst E. Laetrile for cancer: a systematic review of the clinical evidence. Support Care Cancer. 2007 Jun;15(6):583-95.
  31. Bromley J, Hughes BG, Leong DC, Buckley NA. Life-threatening interaction between complementary medicines: cyanide toxicity following ingestion of amygdalin and vitamin C. Ann Pharmacother. 2005 Sep;39(9):1566-9.
Legal notice
The present documentation has been compiled by the CAM-CANCER Project with all due care and expert knowledge. However, the CAM-CANCER Project provides no assurance, guarantee or promise with regard to the correctness, accuracy, up-to-date status or completeness of the information it contains. This information is designed for health professionals. Readers are strongly advised to discuss the information with their physician. Accordingly, the CAM-CANCER Project shall not be liable for damage or loss caused because anyone relies on the information.