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laetrile

The Columbia Encyclopedia, 6th ed. | 2008 | Copyright

laetrile , name given to the chemical amygdalin, a substance derived from an extract of the kernels of many fruits, notably apricots, bitter almonds, and peaches. The idea that laetrile might selectively destroy cancer cells was developed by Dr. Ernst T. Krebs, Sr., a German immigrant to the United States, in the 1920s and was later refined by his son Ernst T. Krebs, Jr., who used the name "vitamin B17" for amygdalin and the derivatives of amygdalin that he developed. The Krebses had hypothesized that an enzyme that was more abundant in tumor cells than normal cells acted on laetrile to produce cytotoxic cyanide. (Cyanide is naturally produced in the intestines when laetrile is acted upon by intestinal bacteria.) This hypothesis and several refinements of it were proved to be untrue, as was the younger Krebs's later classification of the substance as a vitamin.

The subject of controversy for many years, laetrile was subjected to much scientific scrutiny in the 1970s. Investigations showed that anecdotal reports of improvement with laetrile were insufficient proof of effectiveness. Clinical trials showed no effectiveness in shrinking tumors, prolonging survival, or improving the quality of the patient's life. Toxicity from cyanide poisoning in some patients, coupled with the drug's ineffectiveness, led the Food and Drug Administration to label laetrile a fraud. Interstate shipment and shipment from other countries are illegal, but it is still legal in some states and in Mexico.

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laetrile

A Dictionary of Food and Nutrition | 2005 | | Copyright

laetrile Name given to an extract of apricot kernels, amygdalin. Claimed as a cancer cure, although there is no supporting evidence, and sometimes called vitamin B₁₇, although there is no evidence that it is a dietary essential or has any metabolic function.

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DAVID A. BENDER. "laetrile." A Dictionary of Food and Nutrition. 2005. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>.

DAVID A. BENDER. "laetrile." A Dictionary of Food and Nutrition. 2005. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1O39-laetrile.html

DAVID A. BENDER. "laetrile." A Dictionary of Food and Nutrition. 2005. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O39-laetrile.html

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vitamin B17

A Dictionary of Food and Nutrition | 2005 | | Copyright

vitamin B17 Laetrile; no evidence that it has any physiological function in the body, so not a vitamin.

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DAVID A. BENDER. "vitamin B17." A Dictionary of Food and Nutrition. 2005. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>.

DAVID A. BENDER. "vitamin B17." A Dictionary of Food and Nutrition. 2005. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1O39-vitaminB17.html

DAVID A. BENDER. "vitamin B17." A Dictionary of Food and Nutrition. 2005. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O39-vitaminB17.html

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Free newspaper and magazine articles

	Online Laetrile Vendor Ordered to Shut Down. Magazine article from: FDA Consumer; 3/1/2001
	Laetrile. (Shorts). Magazine article from: Townsend Letter for Doctors and Patients; 6/1/2002
	Lengthy jail sentence for vendor of Laetrile--A quack medication to treat... M2 Presswire; 6/24/2004