Health Care Professional Information
Scientific Name
D-mandelonitrile-b-D-glucosido-6-b-D-glucoside
Common Name
Apricot pits, vitamin B17, mandelonitrile-beta-glucuronide (semi-synthetic), mandelonitrile beta-D-gentiobioside (natural product), laevorotatory and mandelonitrile, prunasin
Brand Name
Laetrile®, Amigdalina, NovoDalin B17
Clinical Summary
Amygdalin is a naturally occurring cyanogenic glycoside derived from nuts, plants, and the pits of certain fruits, primarily apricots. It was first used as a cancer treatment in Russia in 1845 and later, in the 1920s, in the United States. It became popular once again in the 1970s, faded away after negative study results, and saw a resurgence in the early 2000. Although patients use amygdalin in oral, injectable and IV forms, there is no evidence documenting effectiveness. Amygdalin is metabolized by the enzyme beta-glucosidase into benzaldehyde, glucose and cyanide(1).
Claims of its anticancer activity rely on the theory, now proven false, that cancer cells contain elevated amounts of the beta-glucosidase compared to normal cells (1). The cyanide resulting from the hydrolysis of amygdalin is believed to be cytotoxic (2). It was further postulated that normal cells convert the cyanide to benign thiocyanate. However, there is no convincing evidence for this selective effect on neoplastic cells. It has also been claimed by some promoters that amygdalin is in fact a vitamin (B17) and that cancer develops due to deficiencies in B17, but no data substantiate this idea.
Laboratory studies suggest that amygdalin has anticancer properties (3) (13), but a 1982 clinical trial conducted by the National Cancer Institute failed to find any effectiveness. Moreover, several study patients had symptoms of mild cyanide toxicity or significant levels of cyanide (4). Systematic reviews of several studies concluded that amygdalin is ineffective as a cancer treatment (5) (6).
Amygdalin is banned in the United States, but is available in Mexico and via the Internet. Evaluation of the parenteral formulation showed contamination with both pyrogens and microbes, and both oral and parenteral formulations did not contain the labeled amounts of amygdalin. Oral administration of Amygdalin has resulted in cyanide toxicity and death. Patients should not use this supplement.
Purported Uses
- Cancer prevention
- Cancer treatment
Constituents
- D-mandelonitrile-b-D-glucosido-6-b-D-glucoside
Mechanism of Action
The mechanism of action is unknown. Claims for amygdalin's activity rely on the theory, now proven false, that cancer cells contain elevated amounts of beta-glucosidase and reduced levels of rhodanese compared to normal cells (1) (2). Based on this incorrect assumption, cancer cells were claimed to metabolize amygdalin into cyanide and die, while healthy cells would convert cyanide to benign thiocyanate via rhodanese. Limited in vitro data support the idea that cyanide, benzaldehyde, and prunasin are cytotoxic. It has also been postulated that cancer develops due to deficiencies in vitamin B17, but no data substantiate this idea (7).
Pharmacokinetics
Hydrocyanic acid, or cyanide, and benzaldehyde are formed from mandelonitrile when amygdalin is metabolized by beta-glucosidase enzymes in the cell. Administration of amygdalin 4.5 grams/m2 intravenously to cancer patients displays two-compartment open model kinetics. Elimination half-life is approximately 2 hours with a mean clearance of 99 ml/min. No changes in whole blood levels of cyanide or thiocyanate were noted with parenteral administration (8). Repeated oral administration of amygdalin 500 mg tablets in cancer patients resulted in increased whole blood cyanide levels of averaging approximately 1 mcg/ml (range 0-3 mcg/ml) (2).
Warnings
Amygdalin is not approved for use in the United States.
Pharmaceutical evaluation of the injectable formulation showed pyrogen and microbial contamination, and both injectable and oral dosage forms did not contain labeled amount of amygdalin.
(12)
Adverse Reactions
Reported (oral): Dermatitis and cyanide toxicity consisting of nausea, vomiting, headache, dizziness, mental obtundation, cyanosis, hypotension, ptosis, neuropathies, coma, and death.
(4) (8) (10) (11)
Reported (oral): Severe cyanide poisoning following ingestion of 3 grams of amygdalin with concurrent use of high doses of vitamin C.
(12)
Literature Summary and Critique
Milazzo S, Ernst E, Lejeune S, Boehm K, Horneber M. Laetrile treatment for cancer. Cochrane Database Syst Rev. 2011 Nov 9;11:CD005476.
This review was conducted to assess the anti-cancer and possible adverse effects of laetrile and amygdalin. The databases CENTRAL (2011, Issue 1); MEDLINE (1951-2011); EMBASE (1980-2011); AMED; Scirus; CancerLit; CINAHL (all from 1982-2011); CAMbase (from 1998-2011); the MetaRegister; and the National Research Register were searched for the review. A total of 69 studies were evaluated, but none met the inclusion criteria. Researchers concluded that the claims of beneficial effects made for laetrile or amygdalin are currently not supported by any clinical data. Further, there is a great risk of serious side effects from cyanide poisoning, espeically following oral consumption of laetrile or amygdalin.
Dosage (Inside MSKCC Only)
This field is only visible to only Inside MSKCC users.
References
- Newmark J, Brady RO, Grimley PM, et al. Amygdalin (Laetrile) and prunasin beta-glucosidases: distribution in germ-free rat and in human tumor tissue. Proceedings of the National Academy of Sciences of the United States of America. Oct 1981;78(10):6513-6516.
- Ames MM, Moyer TP, Kovach JS, et al. Pharmacology of amygdalin (laetrile) in cancer patients. Cancer chemotherapy and pharmacology. 1981;6(1):51-57.
- Fukuda T, Ito H, Mukainaka T, et al. Anti-tumor promoting effect of glycosides from Prunus persica seeds. Biological & pharmaceutical bulletin. Feb 2003;26(2):271-273.
- Moertel CG, Fleming TR, Rubin J, et al. A clinical trial of amygdalin (Laetrile) in the treatment of human cancer. The New England journal of medicine. Jan 28 1982;306(4):201-206.
- Milazzo S, Lejeune S, Ernst E. Laetrile for cancer: a systematic review of the clinical evidence. Supportive care in cancer : official journal of the Multinational Association of Supportive Care in Cancer. Jun 2007;15(6):583-595.
- Milazzo S, Ernst E, Lejeune S, et al. Laetrile treatment for cancer. Cochrane Database Syst Rev. 2011;11:CD005476.
- Greenberg DM. The case against laetrile: the fraudulent cancer remedy. Cancer. Feb 15 1980;45(4):799-807.
- Moertel CG, Ames MM, Kovach JS, et al. A pharmacologic and toxicological study of amygdalin. JAMA : the journal of the American Medical Association. Feb 13 1981;245(6):591-594.
- Davignon JP, Trissel LA, Kleinman LM. Pharmaceutical assessment of amygdalin (Laetrile) products. Cancer treatment reports. Jan 1978;62(1):99-104.
- Sadoff L, Fuchs K, Hollander J. Rapid death associated with laetrile ingestion. JAMA : the journal of the American Medical Association. Apr 14 1978;239(15):1532.
- Kalyanaraman UP, Kalyanaraman K, Cullinan SA, et al. Neuromyopathy of cyanide intoxication due to "laetrile" (amygdalin). A clinicopathologic study. Cancer. Jun 1 1983;51(11):2126-2133.
- Bromley J, Hughes BG, Leong DC, et al. Life-threatening interaction between complementary medicines: cyanide toxicity following ingestion of amygdalin and vitamin C. The Annals of pharmacotherapy. Sep 2005;39(9):1566-1569.
- Chen Y, Ma J, Wang F, et al. Amygdalin induces apoptosis in human cervical cancer cell line HeLa cells. Immunopharmacol Immunotoxicol. 2013 Feb;35(1):43-51.
Consumer Information
How It Works
Bottom Line: Amygdalin (Laetrile) has toxic side effects and has caused decreased survival in cancer patients.
Amygdalin (also called Laetrile®) is an extract from apricot pits that can be metabolized to cyanide, a known poison. It was first used in the 1920s and was promoted widely in the 1950s as a cancer therapy. Promoters claimed that the cyanide released from amygdalin selectively killed cancer cells, leaving normal tissue cells alone. This theory has been proven false by laboratory experiments that showed that amygdalin, when fed to laboratory animals that had cancer cells implanted in them, was not able to reduce the size or slow the growth of their tumors. This was true for many different types of cancer cells. Cyanide does kill cells in laboratory experiments, but affects all cells (both cancerous and healthy) in the same way, which explains the handful of cyanide poisonings that have been reported in cancer patients using amygdalin/Laetrile®.
Purported Uses
- To prevent and treat cancer
Laboratory and clinical evidence does not support this use.
Amygdalin (Laetrile®) has been linked to several cases of cyanide poisoning in cancer patients.
Research Evidence
Cancer treatment:
A review was conducted to determine the anti-cancer and possible adverse effects of laetrile and amygdalin. The databases CENTRAL (2011, Issue 1); MEDLINE (1951-2011); EMBASE (1980-2011); AMED; Scirus; CancerLit; CINAHL (all from 1982-2011); CAMbase (from 1998-2011); the MetaRegister; and the National Research Register were searched for the review. A total of 69 studies were evaluated, but none met the inclusion criteria of the review. Researchers concluded that the claims of beneficial effects made for laetrile or amygdalin are currently not supported by any clinical data. Further, there is a great risk of serious side effects from cyanide poisoning, espeically following oral consumption of laetrile or amygdalin.
Patient Warnings
- Amygdalin is not an approved drug in the United States.
- Laboratory analysis showed that some samples of amygdalin have been contaminated with microbes and pyrogens (substances that induce fever). This analysis also showed that both the injectable and oral dosage forms contained less active product than was claimed on the label.
Side Effects
- Dermatitis (inflammation and redness of the skin)
- Cyanide toxicity from high doses or prolonged use of amygdalin can cause nausea, vomiting, headaches, dizziness, mental confusion, cyanosis (bluish discoloration of the skin), low blood pressure, ptosis (drooping of the eyelids), nerve dysfunction, coma, and death.
Special Point
The Food and Drug Administration has banned the sale and use of amygdalin (Laetrile®) due to the risk of cyanide poisoning. For this reason, Laetrile® is only offered at alternative medicine clinics in Tijuana, Mexico as a component of multi-modality metabolic therapies. Such therapies generally have not been found effective and are discussed at greater length in a separate monograph about metabolic therapies.
Last updated: December 10, 2012
administration (ad-MIH-nih-STRAY-shun)
In medicine, the act of giving a treatment, such as a drug, to a patient. It can also refer to the way it is given, the dose, or how often it is given.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)alternative medicine (all-TER-nuh-tiv MEH-dih-sin)
Practices used instead of standard treatments. They generally are not recognized by the medical community as standard or conventional medical approaches. Examples of alternative medicine include dietary supplements, megadose vitamins, herbal preparations, special teas, acupuncture, massage therapy, magnet therapy, spiritual healing, and meditation.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)amygdalin (uh-MIG-duh-lin)
A substance found in the pits of many fruits such as apricots and papayas, and in other foods. It has been tried in some countries as a treatment for cancer, but it has not been shown to work in clinical studies. Amygdalin is not approved for use in the United States. Also called laetrile.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)analysis (uh-NA-lih-sis)
A process in which anything complex is separated into simple or less complex parts.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)benign (beh-NINE)
Not cancerous. Benign tumors may grow larger but do not spread to other parts of the body. Also called nonmalignant.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)benzaldehyde (ben-ZAL-deh-hide)
A chemical used in flavorings and in some dyes, perfumes, and medicines. It is found in essential oils made from almonds and peach pits and in other foods. It can also be made in the laboratory.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)blood (blud)
A tissue with red blood cells, white blood cells, platelets, and other substances suspended in fluid called plasma. Blood takes oxygen and nutrients to the tissues, and carries away wastes.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)blood pressure (blud PREH-sher)
The force of circulating blood on the walls of the arteries. Blood pressure is taken using two measurements: systolic (measured when the heart beats, when blood pressure is at its highest) and diastolic (measured between heart beats, when blood pressure is at its lowest). Blood pressure is written with the systolic blood pressure first, followed by the diastolic blood pressure (for example 120/80).
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)cancer (KAN-ser)
A term for diseases in which abnormal cells divide without control and can invade nearby tissues. Cancer cells can also spread to other parts of the body through the blood and lymph systems. There are several main types of cancer. Carcinoma is a cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is a cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is a cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system. Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord. Also called malignancy.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)clinical (KLIH-nih-kul)
Having to do with the examination and treatment of patients.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)coma (KOH-muh)
A condition in which a patient is in a state of deep sleep and cannot be awakened. A coma may be caused by many things, including trauma, drugs, toxins, or certain diseases.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)confusion (kun-FYOO-zhun)
A mental state in which one is not thinking clearly.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)cyanide (SY-uh-nide)
A poisonous chemical found in some foods and plants, tobacco smoke, and when certain substances are burned. It is used to make products such as paper, fabric, and plastic, and is used as a pesticide. Cyanide keeps cells in the body from using oxygen, so they die. Exposure to cyanide may cause serious health effects, including death.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)cyanosis (SY-uh-NOH-sis)
Blue-colored skin caused by too little oxygen in the blood.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)cytotoxic (SY-toh-TOK-sik)
Cell-killing.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)dermatitis (DER-muh-TY-tis)
Inflammation of the skin.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)drug (drug)
Any substance, other than food, that is used to prevent, diagnose, treat or relieve symptoms of a disease or abnormal condition. Also refers to a substance that alters mood or body function, or that can be habit-forming or addictive, especially a narcotic.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)dysfunction (dis-FUNK-shun)
A state of not functioning normally.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)extract (EK-strakt)
In medicine, a preparation of a substance obtained from plants, animals, or bacteria and used as a drug or in drugs.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)Food and Drug Administration (... ad-MIH-nih-STRAY-shun)
An agency in the U.S. federal government whose mission is to protect public health by making sure that food, cosmetics, and nutritional supplements are safe to use and truthfully labeled. The Food and Drug Administration also makes sure that drugs, medical devices, and equipment are safe and effective, and that blood for transfusions and transplant tissue are safe. Also called FDA.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)hydrolysis (hy-DRAH-lih-sis)
A chemical reaction that uses water to break down a compound.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)hypotension (HY-poh-TEN-shun)
Abnormally low blood pressure.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)in vitro (in VEE-troh)
In the laboratory (outside the body). The opposite of in vivo (in the body).
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)ingestion (in-JES-chun)
Taking into the body by mouth.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)laetrile (LAY-eh-tril)
A substance found in the pits of many fruits such as apricots and papayas, and in other foods. It has been tried in some countries as a treatment for cancer, but it has not been shown to work in clinical studies. Laetrile is not approved for use in the United States. Also called amygdalin.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)metabolic (MEH-tuh-BAH-lik)
Having to do with metabolism (the total of all chemical changes that take place in a cell or an organism to produce energy and basic materials needed for important life processes).
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)National Cancer Institute (NA-shuh-nul KAN-ser IN-stih-TOOT)
The National Cancer Institute, part of the National Institutes of Health of the United States Department of Health and Human Services, is the Federal Government's principal agency for cancer research. The National Cancer Institute conducts, coordinates, and funds cancer research, training, health information dissemination, and other programs with respect to the cause, diagnosis, prevention, and treatment of cancer. Access the National Cancer Institute Web site at . Also called NCI.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)nausea (NAW-zee-uh)
A feeling of sickness or discomfort in the stomach that may come with an urge to vomit. Nausea is a side effect of some types of cancer therapy.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)nerve (nerv)
A bundle of fibers that receives and sends messages between the body and the brain. The messages are sent by chemical and electrical changes in the cells that make up the nerves.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)obtundation (ob-tun-DAY-shun)
A dulled or reduced level of alertness or consciousness.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)oral (OR-ul)
By or having to do with the mouth.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)ptosis (TOH-sis)
Drooping of the upper eyelid.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)significant (sig-NIH-fih-kunt)
In statistics, describes a mathematical measure of difference between groups. The difference is said to be significant if it is greater than what might be expected to happen by chance alone. Also called statistically significant.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)therapy (THAYR-uh-pee)
Treatment.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)tissue (TIH-shoo)
A group or layer of cells that work together to perform a specific function.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)toxicity (tok-SIH-sih-tee)
The extent to which something is poisonous or harmful.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)vitamin (VY-tuh-min)
A nutrient that the body needs in small amounts to function and stay healthy. Sources of vitamins are plant and animal food products and dietary supplements. Some vitamins are made in the human body from food products. Vitamins are either fat-soluble (can dissolve in fats and oils) or water-soluble (can dissolve in water). Excess fat-soluble vitamins are stored in the body’s fatty tissue, but excess water-soluble vitamins are removed in the urine. Examples are vitamin A, vitamin C, and vitamin E.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)vitamin C (VY-tuh-min…)
A nutrient that the body needs in small amounts to function and stay healthy. Vitamin C helps fight infections, heal wounds, and keep tissues healthy. It is an antioxidant that helps prevent cell damage caused by free radicals (highly reactive chemicals). Vitamin C is found in all fruits and vegetables, especially citrus fruits, strawberries, cantaloupe, green peppers, tomatoes, broccoli, leafy greens, and potatoes. It is water-soluble (can dissolve in water) and must be taken in every day. Vitamin C is being studied in the prevention and treatment of some types of cancer. Also called ascorbic acid.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)
