Laetrile in therapeutics
Laetrile, a semi-synthetic form of amygdalin often referred to as vitamin B17, has been promoted as a potential cancer treatment despite significant controversy surrounding its efficacy and safety. Originally identified in the 1830s and later synthesized in the 1950s, laetrile is derived from the pits of certain fruits and is notorious for breaking down into cyanide, a harmful toxin. While some proponents advocate for its anticancer properties, claiming that it selectively targets cancer cells, extensive scientific research has consistently dismissed these claims, finding no credible evidence supporting its effectiveness in cancer treatment.
Health experts, including oncology professionals, caution against laetrile use due to its potential risks, including severe adverse reactions akin to cyanide poisoning. Regulatory bodies, such as the U.S. Food and Drug Administration (FDA), have not approved laetrile, and its sale is illegal within the United States. Despite this, some alternative medicine practitioners, particularly in Mexico, continue to offer laetrile treatments to patients.
Recent laboratory studies have noted some cellular benefits of laetrile, prompting further research, but these findings do not establish it as a safe or effective option for human cancer treatment. Those considering alternative therapies are advised to consult healthcare professionals to avoid harmful interactions with conventional cancer treatments.
Laetrile in therapeutics
DEFINITION: A potentially deadly, purported cancer cure dismissed as ineffective by the scientific community.
Overview
Laetrile is a pure semi-synthetic form of the chemical amygdalin, sometimes called vitamin B17. This compound occurs naturally in many fruit pits and nuts. French chemists first identified it in 1830 and found that when amygdalin breaks down, it produces the poison cyanide.
Laetrile continues to attract the attention of health consumers and regulatory authorities. Cancer experts and health fraud watchdogs are concerned about the risks of taking this substance and of patients being duped. There is little evidence in support of laetrile’s proposed anticancer properties and considerable evidence of its dangers. Even so, glowing testimonials fill supporters’ websites.
“The primary risk of using any unproven treatment for cancer is the patient forgoes traditional treatment that could help them,” says oncologist Clarence Brown, president of the M.D. Anderson Cancer Center in Orlando, Florida. “Secondly, they may be taking something that’s harmful to them. It could interact with other medications. Or they could have a bad reaction. And they’re spending, oftentimes, big dollars to take a treatment that has absolutely no benefit.”
Vitamin B17 and apricot kernels are other names for laetrile. It is not a vitamin. Some advocates believe cancer results from a vitamin deficiency that laetrile can presumably correct. Opponents think the term “laetrile” was coined to avoid federal drug safety and efficacy requirements.
Theories on Laetrile
During the nineteenth century, doctors tried using amygdalin to treat cancer. It proved too toxic. In the 1950s, a semisynthetic form called laetrile was produced and promoted as a cancer cure. Several theories exist about its anticancer action. In addition to the “vitamin” theory, some supporters believe an enzyme found primarily in cancer cells but lacking in healthy cells breaks down amygdalin. The amygdalin is broken down to cyanide, which then kills the cancer.
“Every cancer cell has a prodigious quantity of beta-glucosidase, or the unlocking enzyme,” says G. Edward Griffin, who maintains that laetrile works and who published the supporting book World Without Cancer: The Story of Vitamin B17 (2001). None of these theories has held up well under scientific scrutiny.
Scientific Studies
Laetrile gained notoriety in the 1970s when doctors had fewer effective cancer treatments. Chemotherapy's side effects were hard to control. Patients began looking for other options. More than seventy thousand Americans had tried laetrile by 1978. That year, the National Cancer Institute (NCI) reviewed cases submitted by doctors touting its benefits. Only two of sixty-seven patients had a complete response. Tumors got smaller in four others.
The NCI then sponsored research to evaluate laetrile. Two of the six persons in the first study died of cyanide poisoning after eating almonds. During the second study, patients received an infusion of amygdalin, followed by laetrile pills. Some participants reported feeling better while taking the drug, but cancer progressed in all 175 participants by the end of treatment. The agency decided not to investigate further. The American Cancer Society concluded laetrile had no role in cancer care. A further systematic review of laetrile’s effectiveness published in 2015 confirmed there is no clinical evidence of its ability to be an anticancer medication and that misuse of laetrile could be toxic. The National Cancer Institute, as well as all reputable cancer hospitals in the United States, remain steadfast in their belief that though lab results sometimes point to laetrile’s effectiveness in treating cancer, these results simply have not been duplicated in human clinical studies.
Despite laetrile's volatile nature as a cancer treatment in its natural form, scientists continue to study its cellular properties. In the early 2020s, several studies found several beneficial characteristics of laetrile at the cellular level, which may help inform a new body of cancer treatment research. Laetrile exhibited anticancer properties, induced apoptosis, stopped the spread of cancer cells, and, when combined with beat-glucosidase, helped kill prostate cancer cells. However, these studies were performed in a lab on individual cells rather than animal or human studies. Their promising results indicate further research is warranted, but they do not indicate laetrile is a safe supplement or an effective cancer treatment in humans.
Use of Laetrile in the Twenty-First Century
The US Food and Drug Administration (FDA) has not approved the use of laetrile and has taken action against companies in the United States to halt online sales of laetrile. The US Supreme Court banned its interstate shipment in 1980, and it is illegal to bring it into the United States for personal use. “This product has not been found to be safe and effective, so they’re in violation of US drug laws,” says FDA spokesperson Susan Cruzan of organizations that sell laetrile.
Mexican doctors, for example, still give laetrile to patients despite the lack of scientific evidence. Oasis of Hope Hospital spokesperson Alex Phillips said that in several decades, his Tijuana facility has treated 100,000 persons with laetrile. Patients initially receive laetrile through a vein. Then they take laetrile tablets, sometimes for the rest of their lives.
In 2019, the FDA issued a special alert concerning laetrile, its dangers, and its ineffective use as a cancer treatment.
Safety Issues
Adverse reactions to laetrile are similar to those that occur with cyanide poisoning. Eating raw almonds or some fruits and vegetables when taking laetrile increases the risk of having an adverse reaction. Side effects tend to be more severe when laetrile is ingested, and some persons have died from laetrile treatment. Adverse effects of laetrile include nausea, vomiting, headache, dizziness, bluish skin color, droopy eyelids, trouble walking, fever, and confusion.
General Advice
People with cancer who want to try alternative therapies should consult a doctor if they are considering laetrile or other therapies. Also, consumers should know that herbal remedies can interfere with drugs ordered by a doctor.
Bibliography
Al-Khafaji, Khattab, and Tugba Taskin Tok. “Understanding the Mechanism of Amygdalin’s Multifunctional Anti-Cancer Action Using Computational Approach.” Journal of Biomolecular Structure & Dynamics, vol. 39, no. 5, 2021, pp. 1600–10. doi.org/10.1080/07391102.2020.1736159. Accessed 21 Nov. 2024.
“Amygdalin.” Memorial Sloan Kettering Cancer Center, 7 July 2021, www.mskcc.org/cancer-care/integrative-medicine/herbs/amygdalin. Accessed 20 Sept. 2024.
Blackmer, Nick. "What to Know about Vitamin B17." Verywell Health, 19 Aug. 2024, www.verywellhealth.com/laetrile-amygdalin-89572. Accessed 20 Sept. 2024.
“Laetrile/Amygdalin.” National Cancer Institute, 2 June 2022, www.cancer.gov/about-cancer/treatment/cam/patient/laetrile-pdq. Accessed 20 Sept. 2024.
Marks, Julie. "Is Amygdalin a Safe Cancer Treatment?" WebMD, 29 Feb. 2024, www.webmd.com/cancer/amygdalin-cancer-treatment. Accessed 20 Sept. 2024.
Milazzo, Stefania, et al. "Laetrile Treatment for Cancer." The Cochrane Database of Systematic Reviews, vol. 4, 2015. doi.org/10.1002/14651858.CD005476.pub4.
U.S. Food and Drug Administration. www.fda.gov.