FOOD SAFETY

Several foods can naturally contain toxins, many of which are not produced by bacteria. Plants in particular may be toxic; animals which are naturally poisonous to eat are rare. In evolutionary terms, animals can escape being eaten by fleeing; plants can use only passive defenses such as poisons and distasteful substances, for example capsaicin in chili peppers and pungent sulfur compounds in garlic and onions. Most animal poisons are not synthesised by the animal, but acquired by eating poisonous plants to which the animal is immune, or by bacterial action.
Alkaloids
Ciguatera poisoning
Grayanotoxin (honey intoxication)
Mushroom toxins
Phytohaemagglutinin (red kidney bean poisoning; destroyed by boiling)
Pyrrolizidine alkaloids
Shellfish toxin, including paralytic shellfish poisoning, diarrhetic shellfish poisoning, neurotoxic shellfish poisoning, amnesic shellfish poisoning and ciguatera fish poisoning
Scombrotoxin
Tetrodotoxin (fugu fish poisoning)
Some plants contain substances which are toxic in large doses, but have therapeutic properties in appropriate dosages.
Foxglove contains cardiac glycosides.
Poisonous hemlock (conium) has medicinal uses.