Unsafe "cancer remedy" amygdalin/laetrile - no end in sight: The seeds (kernels) of stone fruits such as apricots or bitter almonds contain up to 8% amygdalin, a cyanogenic glycoside. Amygdalin and its derivatives such as laetrile are not licensed as medicines, but have been propagated for decades, also under the appellation of Vitamin B17, as a cancer treatment - increasingly as a food supplement and also combined with the consumption of amygdalin-containing bitter apricot kernels or with high doses of Vitamin C. The description as Vitamin B17 is misleading, as amygdalin is not necessary for the human metabolism (1). The amygdalin chapter could and should, actually, have been closed long ago: The US Food and Drug administration (FDA) has been warning against the "quack medication" (2) for decades (a-t 1978; No. 4: 42 and No. 11: 100). In 1982, in a study sponsored by the National Cancer Institute with 178 patients, no benefit could be established, either in relation to the cure, stabilisation or improvement of the disease, or in terms of prolongation of life, but actually it was found to entail considerable risks (a-t 1982; No. 2: 14) (3). Furthermore, a current Cochrane review has come up with a negative risk-benefit balance (4). Proponents claim that amygdalin does not damage healthy cells.* The enzyme beta-glucosidase is purposed to exist in high concentrations in cancer cells and release cyanhydric acid from amygdaline (salt: cyanide), and thus selectively destroy malignant cells. This hypothesis was already refuted in the 1980s by measuring the enzyme concentrations in both healthy and cancerous tissue (1). An author from the Federal Institute for Drugs and Medicinal Devices (BfArM) warns, in view of the lack of evidence of any benefit, that amygdalin can cause considerable adverse effects such as headaches, dizziness, nausea and vomiting, and that it presents the risk of elevated cyanide levels (above 3 µg/ml), which lie in a range that has been described in the existing cases of death. The simultaneous consumption of foods with a high beta-glucosidase content, which includes for example apricot kernels, increases the risk of symptomatic cyanide toxicity (1). The risk of cyanide poisoning continues to rise when Vitamin C is administered in high doses at the same time, as this increases the production of cyanide in vitro and diminishes the body's reserves of cysteine, which contributes to the detoxification of cyanide (5). According to the BfArM, amygdalin is an unsafe remedy that must not be placed on the market and the administration of which is inadmissible, even on medical prescription (1). Advocates of amygdalin treatment for cancer create confusion on a number of internet sites* with conspiracy theories (see blitz-a-t, June 16, 2000): They claim that this natural "vitamin" is not of interest to the pharmaceutical cartels as it cannot be patented, and that the medical establishment has still been able to deprive the public of information about the remedy. We renew our warning in the strongest terms against this kind of quackery, -Ed.

(M = meta-analysis)

1

LILIENTHAL, N. (BfArM): Bull. z. Arzneimittelsicherheit 2014 (Nr. 3): 7-13; http://www.a-turl.de/?k=elgw

2

FDA: press release dated 22 June 2004

3

MOERTEL, C.G. et al.: N. Engl. J. Med. 1982; 306: 201-6

4

MILAZZO, S. et al.: Laetrile treatment for cancer. Cochrane Database of Systematic Reviews, Stand Sept. 2011, accessed Oct. 2014

5

BROMLEY, J. et al.: Ann. Pharmacother. 2005; 39: 1566-9

e.g.: http://heilpraktiker-warnemünde.de/amygdalin-vitamin-b17