Laetrile
Laetrile, also known as amygdalin or sometimes referred to as vitamin B17, is a compound derived from the seeds of fruits like almonds and apricots. It gained attention as a supposed cancer treatment, particularly during the 1970s, despite a lack of scientific evidence supporting its effectiveness. Laetrile can break down into cyanide in the body, which poses significant health risks, including toxicity and even fatal outcomes due to cyanide poisoning. While some proponents suggest that cyanide could have anticancer properties, clinical studies have not validated these claims. Research has shown that laetrile does not cure cancer, and its use can lead to dangerous side effects, including nausea and vomiting. Although laetrile was legalized in some states following a court challenge, it was ultimately banned by the FDA in 1980 due to safety concerns. Today, laetrile is still produced and used in Mexico, but it remains controversial and poses ethical questions in medical research due to its potential dangers.
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Laetrile
ALSO KNOWN AS: Amygdalin, mandelonitrile beta-D-gentiobioside, mandelonitrile-beta-glucuronide, vitamin B17, amigdalina B-17
DEFINITION: Laetrile is a modified form of amygdalin, a glycoside that is extracted from almonds and the pits of apricots and peaches. It was formerly marketed as a cancer treatment, but its effectiveness was never proven, and it is considered dangerous, as it can break down into cyanide in the gut.
Cancers treated or prevented: None
Delivery routes: Injection, intravenously, pill, enema
How this substance works: Amygdalin was first extracted in 1830 and used as an anticancer drug in Russia in 1845. The popularity of laetrile reemerged in the 1970s, and a court challenge succeeded in legalizing its use. Twenty states legalized laetrile as a result of the challenge. Laetrile, however, was not approved by the Food and Drug Administration (FDA) to treat cancer or any other disease. In 1980, a federal ban on laetrile made purchasing it in the United States impossible. It is, however, manufactured and used for cancer treatment in Mexico. Even taken as a supplement, laetrile can be toxic and fatal because of the risk of cyanide poisoning. There are known deaths directly attributable to laetrile use and the resulting cyanide poisoning.
Proponents believe that cyanide has anticancer effects. Laboratory and clinical studies have yielded no data supporting the effectiveness of laetrile as an anticancer drug. Human studies have yielded inconclusive results. In some studies, patients were given traditional cancer treatment along with laetrile. Thus, it was not possible to study the laetrile independently. A study published in 1982, however, followed 175 patients with different types of cancer who took laetrile. The cancer returned in all patients by eight months. No patient was cured of cancer by laetrile. Medical researchers found similar results in studies and reviews of studies in the 2020s. While treatment with laetrile showed some potential for laetrile to prevent precancerous cells from multiplying, there was no evidence of its effectiveness in treating cancer. More human and animal studies are necessary, though due to the potential dangers of laetrile, medical ethics is an issue.
The primary mechanism of the most widely held belief in laetrile’s effectiveness is that cyanide has a direct toxic effect on cells by preventing oxygen from being effectively used by the cancer cells, causing them to die. The second main theory is that cancer is caused by a vitamin deficiency and that laetrile (termed vitamin B17) treats the deficiency. Neither of these theories has been shown to be valid.
Side effects: Cyanide poisoning is the main side effect. It causes nausea and vomiting and can be fatal in high doses. Laetrile as a supplement is particularly hazardous to children and pregnant women. Taking raw amygdalin while on laetrile can induce toxic cyanide levels in the blood.
Bibliography
"Amygdalin: Cyanide Poisoning: Case Report." Reactions Weekly, Nov. 2013, p. 7.
Kapoor, Shailendra. "Safety of Studies Analysing Clinical Benefit of Amygdalin." Immunopharmacology and Immunotoxicology, vol. 36, no. 1, 2014, p. 87.
“Laetrile/Amygdalin (PDQ®).” National Cancer Institute, 14 June 2022, www.cancer.gov/about-cancer/treatment/cam/hp/laetrile-pdq. Accessed 15 June 2024.
Makarević, Jasmina, et al. "Amygdalin Blocks Bladder Cancer Cell Growth in Vitro by Diminishing Cyclin A and cdk2." PLoS ONE, vol. 9. no. 8, 2014, pp. 1–9.
Song, Zuoqing, and Xiaohong Xu. "Advanced Research on Anti-Tumor Effects of Amygdalin." Journal of Cancer Research and Therapeutics, vol. 10, suppl. 5, 2014, pp. C3–C7.
Spanoudaki, Maria, et al. "Amygdalin As a Promising Anticancer Agent: Molecular Mechanisms and Future Perspectives for the Development of New Nanoformulations for Its Delivery." International Journal of Molecular Sciences, vol. 24, no. 18, 2023, p. 14270, doi.org/10.3390/ijms241814270. Accessed 15 June 2024.