Apricot kernels are the seed of the apricot fruit. They have a long history of medicinal use in some cultures. Currently there is considerable controversy over their use as a cancer cure, but the weight of the scientific evidence is against its use. Oil extracted from the kernels has other uses as well, including as an ingredient in skin care products. Apricot kernels are known to contain highly toxic cyanide compounds and should be eaten with caution or not at all.
The kernel is located inside the seed shell, which is what remains when the apricot's flesh has been removed. The seed shell must be cracked open in order to extract the kernel, which is then sometimes eaten whole. Oils and other compounds can also be extracted from the kernel.
According to the American Cancer Society, apricot kernels (also known as bitter almonds) have been used for thousands of years as a part of traditional medicine. Cultures that used the kernels included the Chinese and the Egyptians. Its use today as an alternative cancer treatment began with the theories of Ernst T. Krebs, Sr., MD, who purified the kernel's liquid extract into a form called amygdalin.
Another name given for this substance is "Vitamin B-17." This compound was too toxic for use as any kind of treatment. Krebs' son, Ernst T Krebs, Jr., further developed his fathers' theories and created a new formulation that he called Laetrile. Krebs claimed that this formulation was an effective cancer cure, but it was ultimately banned by the FDA and is illegal in any state without a law explicitly permitting it.
Krebs' claims about the use of Laetrile as a cancer cure depended on his thesis that the substance would attack cancer cells without harming healthy human cells. Unfortunately, no evidence was found that this is the case. Beginning in 1957, more than a dozen studies with tumor cells in animals failed to discover any beneficial effect.
In 1981, a human trial demonstrated the same lack of efficacy. 175 patients were tested, and none manifested any significant effect. Instead, some of the patients developed symptoms of cyanide poisoning, according to "A Clinical Trial of Amygdalin (Laetrile) in the Treatment of Human Cancer," by Dr. Charles Moertel of the Mayo Clinic, published in the Jan. 28, 1982 edition of "The New England Journal of Medicine."
The kernels have been sold whole as a treatment or health food in many locations, but contain cyanide toxins and therefore should not be consumed. One package of the kernels imported from Pakistan was found to contain twice the lethal dose of cyanide, according to the report in the March 26, 1993 issue of "The New York Times."
Despite bitter almonds' toxicity when taken internally, oil extracted from them is used for beauty products. This practice has origins in the same ancient cultures that would use them for medicinal purposes. The oil's effect is to reduce skin roughness and irritation.