Friday Favorites: Do Apricot Seeds Work as an Alternative Cancer Cure?

Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

Does use of alternative medicine in addition to conventional therapies predict prolonged survival from cancer? Even if the alternative therapies themselves were useless, one might predict users would live longer, because they tend to have more hope, a greater will to live; nearly three times as likely to believe their cancer was curable even if it wasn’t. But death rates were actually higher in alternative medicine users. Follow them up years later, and 79 percent of the alternative medicine users had died compared to 65 percent of nonusers. Now if the alternative medicine users started out sicker, that could certainly explain that, and they did tend to be, though the difference didn’t reach statistical significance. Bottom line: the association between the use of alternative medicine and shortened survival is not necessarily cause and effect, but it’s possible some of the alternative modalities may have indeed been harmful.

Thanks to the internet, there has been a resurgence of older complementary and alternative cancer treatments, such as laetrile, which is a compound derived from amygdalin, a natural cyanide-containing substance concentrated in apricot kernels, the seeds inside the pits. It was branded as a “vitamin” to skirt regulations—vitamin B-17—but it’s not a vitamin, and the lack of laetrile’s effectiveness against cancer and the risk of side effects from cyanide poisoning led to it being banned decades ago. However, no surprise, you can still buy it on the internet, along with the apricot kernels themselves. Why not just give them a try, though? Because of cyanide intoxication.

Here’s a typical case report. Woman ate some apricot seeds she got at a health food store. So, they’ve got to be healthy, right? Twenty minutes later, she was having trouble breathing, before she slipped into a coma. They made some calculations, and it appears an eight-ounce bag of apricot kernels is enough to kill six people if consumed in one sitting. “Therefore, the continuing sale of apricot kernels as health food is troubling.”

And you never know what you’re getting. Here, this person was consuming a quarter of a teaspoon of ground apricot kernels daily, and had just switched brands the day before she ended up in the ICU. Thankfully, she survived; others are not so lucky, like this 17-year-old who was dead within a day, as severe cyanide poisoning can result in coma, convulsions and cardiovascular collapse. That’s why calling it a vitamin is so insidious. A 32-year-old woman arrives at the emergency room in a coma. Was she on anything? No, she just took some vitamin supplements. Thankfully, a relative showed up with them. Oh, B-17. They gave her a cyanide antidote and she survived. But had that relative not showed up, or been delayed in traffic or something, the case could have proved fatal.

So, “[c]ancer patients should be informed about the high risk of developing serious adverse effects due to cyanide poisoning after laetrile or amygdalin,” the natural compound in apricot seeds. Especially at risk may be those taking megadoses of vitamin C, or those not getting enough vitamin B12. See, the body has two major ways to detoxify cyanide. It can attach it to B12 to form the supplement form cyanocobalamin, which can be harmlessly peed out. Or, it can use the amino acid cysteine, which is also used to metabolize vitamin C, and so if you take too much vitamin C, levels can drop, and you can end up more vulnerable to cyanide toxicity.

But hey, conventional cancer treatments such as chemo can be toxic, too. It’s all about benefits versus risks. Yeah, amygdalin can block the growth of certain cancer cells in a petri dish, though doesn’t appear to have any anti-cancer effects against laboratory animal tumors.  But you don’t know what happens in people…until you put it to the test and do a clinical trial of amygdalin in the treatment of human cancer, which we’ll cover next.

Please consider volunteering to help out on the site.

• Risberg T, Vickers A, Bremnes RM, Wist EA, Kaasa S, Cassileth BR. Does use of alternative medicine predict survival from cancer?. Eur J Cancer. 2003;39(3):372-7.
• Thomson D. Complementary, alternative, proven, unproven. Intern Med J. 2006;36(10):623-4.
• Beadle GF, Yates PM, Najman JM, et al. Beliefs and practices of patients with advanced cancer: implications for communication. Br J Cancer. 2004;91(2):254-7.
• Smith PJ, Clavarino AM, Long JE, Anstey CM, Steadman KJ. Complementary and alternative medicine use by patients receiving curative-intent chemotherapy. Asia Pac J Clin Oncol. 2016;12(3):265-74.
• Milazzo S, Horneber M. Laetrile treatment for cancer. Cochrane Database Syst Rev. 2015;(4):CD005476.
• Ginter E, Simko V. False claims about so called vitamin B 17. Bratisl Lek Listy. 2013;114(4):241.
• Lerner IJ. Laetrile: a lesson in cancer quackery. CA Cancer J Clin. 1981;31(2):91-5.
• O'brien B, Quigg C, Leong T. Severe cyanide toxicity from 'vitamin supplements'. Eur J Emerg Med. 2005;12(5):257-8.
• Seghers L, Walenbergh-van veen M, Salome J, Hamberg P. Cyanide intoxication by apricot kernel ingestion as complimentary cancer therapy. Neth J Med. 2013;71(9):496-8.
• Sadoff L, Fuchs K, Hollander J. Rapid death associated with laetrile ingestion. JAMA. 1978;239(15):1532.
• Sauer H, Wollny C, Oster I, et al. Severe cyanide poisoning from an alternative medicine treatment with amygdalin and apricot kernels in a 4-year-old child. Wien Med Wochenschr. 2015;165(9-10):185-8.
• Moertel CG, Fleming TR, Rubin J, et al. A clinical trial of amygdalin (Laetrile) in the treatment of human cancer. N Engl J Med. 1982;306(4):201-6.
• Makarević J, Tsaur I, Juengel E, et al. Amygdalin delays cell cycle progression and blocks growth of prostate cancer cells in vitro. Life Sci. 2016;147:137-42.
• Chan TY. A probable case of amygdalin-induced peripheral neuropathy in a vegetarian with vitamin B12 deficiency. Ther Drug Monit. 2006;28(1):140-1.
• Suchard JR, Wallace KL, Gerkin RD. Acute cyanide toxicity caused by apricot kernel ingestion. Ann Emerg Med. 1998;32(6):742-4.
• Vlad IA, Armstrong J, Bertilone C, Matisons M. Apricot kernels: a rare case of cyanide toxicity. Emerg Med Australas. 2015;27(5):491-2.
• Basu TK. Possible toxicological aspects of megadoses of ascorbic acid. Chem Biol Interact. 1977;16(2):247-50.
• 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;39(9):1566-9.

Image credit: Iulian.serbanoiu via Wikimedia Commons. Image has been modified.

Motion graphics by Avocado Video