Some cancer patients use laetrile, or amygdalin, because they believe it may help manage or cure the disease, states Cancer Research UK. Other cancer sufferers think that laetrile cleanses the body while boosting energy levels. However, the National Cancer Institute notes conflicting viewpoints on its effectiveness.
As of 2015, there is some laboratory evidence that amygdalin does discourage the growth of some types of cancer cells, according to an abstract published by the National Center for Biotechnology Information. The abstract describes a university study performed on metastasized lung cancer cells. In-vitro results, this study concludes, strongly indicate that amygdalin, or Laetrile, may be viable as a therapy for lung cancers.
Scientists hold different theories of how laetrile may fight cancer, notes the National Cancer Institute. One theory posits that cyanide, produced by the amygdalin plant compound, kills cancer cells while enhancing a patient's immunity. However, two clinical trials performed in the 1970s and 1980s showed that cancer tumors had actually grown in a majority of the participants.
In 2011, the National Cancer Institute confirmed that a review of the existing research discovered no proof that laetrile is an effective treatment for cancer. The Memorial Sloan Kettering Cancer Center cautions that clinical evidence does not substantiate claims that Laetrile is beneficial in treating cancer. In fact, the U.S. Food and Drug Administration has not officially accepted laetrile as a cancer treatment, although it is in use in Mexico and other parts of the world.