Not Medical Advice: According to the modern F.D.A., bitter almonds are poisonous.
Bitter almonds contain a toxic amount of prussic acid (a chemical precursor to cyanide compounds) and hydrocyanic acid (also in the cyanide family).
In an article of Los Angeles Times published on February 20, 2002, the lethal dose of raw bitter almonds depends on the size of the nuts, their concentration of amygdalin and the consumer's sensitivity. But scientists estimate that a 150-pound adult might die from eating between 10 and 70 raw nuts, and a child from ingesting just a few.
A recessive gene causes bitter almond trees to produce in their shoots, leaves and kernels a toxic compound called amygdalin, which serves as a chemical defense against being eaten. When amygdalin is moistened, it splits into edible benzaldehyde, which provides an intense almond aroma and flavor, and deadly hydrocyanic acid, a fast-acting inhibitor of the respiratory system.
Check out some foods that, if handled or consumed incorrectly, can come close to being hazardous to your health at Epicurious.com.