Bitter Almond (Prunus amygdalus Batch var. amara (DC.) Focke) and Laetrile

Bitter Almond (Prunus amygdalus Batch var. amara (DC.) Focke) and Laetrile

Background

The almond is closely related to the peach, apricot, and cherry (all classified as drupes). Unlike the others, however, the outer layer of the almond is not edible. The edible portion of the almond is the seed. A compound called amygdalin differentiates the bitter almond from the sweet almond. In the presence of water (hydrolysis), amygdalin yields glucose and the chemicals benzaldehyde and hydrocyanic acid (HCN). HCN, the salts of which are known as cyanide, is poisonous. To be used in food or as a flavoring agent, the HCN must be removed from the bitter almond oil. Once it is removed, the oil is called volatile almond oil and is considered to be almost pure benzaldehyde. Volatile almond oil can still be toxic in large amounts.

"Laetrile," an alternative cancer drug marketed in Mexico and other countries outside of the U.S., is derived from amygdalin. Multiple cases of cyanide poisoning, including deaths, have been associated with laetrile therapy.

Synonyms

Aci badem, almendra amara, amande amere, amendoa amarga, amygdala amara , Amygdalis dulcis amara , bitter almond oil, bittere amandel, bittermandel, gorkiy mindal, karvasmanteli, keseru mandula, ku wei bian tao, ku xing ren, lawz murr, mandorla amara, Prunus communis amara , Prunus dulcis (Mill.) D.A. Webb var. amara (DC.) H.E. Moore, Prunus amygalus amara, Rosaceae, volatile almond oil.

Note : Bitter almond should not be confused with "sweet almond." Sweet almond seeds do not contain amygdalin and can be eaten, whereas bitter almonds can be toxic.

Evidence

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Uses based on scientific evidenceGrade*Cancer (Laetrile)
"Laetrile" is an alternative cancer drug marketed in Mexico and other countries outside of the U.S. Laetrile is derived from amygdalin, found in the pits of fruits and nuts such as the bitter almond. There are multiple animal studies and initial human evidence to suggest that laetrile is not beneficial in the treatment of cancer. In 1982, the U.S. National Cancer Institute concluded that laetrile was not effective for cancer therapy. Nonetheless, many people still travel to use this therapy outside the U.S. Multiple cases of cyanide poisoning, including deaths, have been associated with laetrile therapy.

D

* Key to grades
A: Strong scientific evidence for this use;
B: Good scientific evidence for this use;
C: Unclear scientific evidence for this use;
D: Fair scientific evidence against this use (it may not work);
F: Strong scientific evidence against this use (it likely does not work).

Uses based on tradition or theory
The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Antibacterial, anti-inflammatory, anti-itch,cough suppressant, local anesthetic, muscle relaxant, pain suppressant, sedative.

Dosing

The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

Standardization

Standardization involves measuring the amount of certain chemicals in products to try to make different preparations similar to each other. It is not always known if the chemicals being measured are the "active" ingredients. Hydrocyanic acid (HCN), also known as cyanide, is present in bitter almond, and is poisonous. To be used in food or as a flavoring agent, HCN must be removed from bitter almond oil. Once it is removed, the oil is called volatile almond oil. Volatile almond oil can still be toxic in large amounts.

"Laetrile" is an alternative cancer drug marketed in Mexico and other countries outside of the U.S. that can be made from a chemical called amygdalin (present in the pits of fruits and nuts such as bitter almond). Mexico supplies the majority of laetrile that has been used by United States citizens, and standardization has been unreliable. Laetrile samples from Mexico have been tested for strength and contamination, and have been found to include lower concentrations of the compound than labeled, and to be contaminated with other chemicals.

Adults (18 years and older)

Due to potential toxicity, there is no widely accepted standard dose for bitter almond.

Children (younger than 18 years)

Due to potential toxicity, bitter almond products should be avoided in children.

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Allergies

Allergies to almonds are common and have lead to severe reactions, including throat swelling that interferes with breathing, and painful swelling under the skin ("angioedema"). If you are allergic to other nuts, it is probably best to avoid almonds. After three weeks of laetrile therapy, a patient developed redness of the skin with a spotted rash. Within two days of stopping laetrile after treatment with cortisone, the rash subsided.

Side Effects and Warnings

Laetrile, derived from the amygdalin found in the pits of fruits and nuts such as the bitter almond, is considered unsafe in any form due to its potential for causing cyanide toxicity. Reactions are more severe when laetrile is taken by mouth than when injected within a vein or into muscle. Some of the side effects have included dilated pupils, dizziness, drooping eyelids, drowsiness, headache, increased breathing, muscle weakness, nausea, stomach pain, and vomiting. High doses of bitter almond or laetrile may lead to a slowing of brain functions or breathing. Several cases of cyanide poisoning (some fatal) have been reported.

In one case, a woman who was taking laetrile for five years developed decreased white blood cells, and when she stopped taking laetrile, the condition disappeared. Another case involved a 22-year-old male who took 12 to 18 laetrile tablets at once in order to make up for missed doses, developed seizures and was admitted to the hospital for cyanide poisoning. An "odor" that smelled like almonds was noted by the hospital staff. Life support measures and treatment for poisoning allowed the patient to fully recover. An 11 month-old girl swallowed one to five 500 milligram laetrile tablets and after 30 minutes was brought to the hospital in a coma with shock and irregular breathing. The patient died within four days. Most cases of overdose have been treated with supportive care, washing out the stomach, hydration, oxygen therapy (with respiratory assistance), and medications like amyl nitrite, sodium nitrite, and sodium thiosulfate to decrease cyanide levels. Drowsiness or sedation may occur with bitter almond. Use caution if you are driving or operating heavy machinery.

Pregnancy and Breastfeeding

Bitter almonds are not recommended due to insufficient available data and potential risk for birth defects. One study reports that laetrile given by mouth to pregnant hamsters causes abnormal skeleton formation in offspring, but intravenous laetrile may not.

References

1. Beamer WC, Shealy RM, Prough DS. Acute cyanide poisoning from laetrile ingestion. Ann Emerg Med 1983; 12(7):449-451.

2. Liegner KB, Beck EM, Rosenberg A. Laetrile-induced agranulocytosis. JAMA 1981; 246 (24) :2841-2842.

3. Moertel CG, Fleming TR, Rubin J et al. A clinical trial of amygdalin (Laetrile) in the treatment of human cancer. N Engl J Med 1982; 306(4):201-206.

4. Shragg TA, Albertson TE, Fisher CJ, Jr. Cyanide poisoning after bitter almond ingestion. West J Med 1982; 136(1):65-69.

5. Willhite CC. Congenital malformations induced by laetrile. Science 1982; 215(4539):1513-1515.

January 01, 2004