Toxic components of natural foodstuffs are discussed, with special reference to lathyrogens, pressor
amines, azoxyglycosides, and labile
sulfur compounds. The osteolathyrogen, gamma-glutamyl-
beta-aminopropionitrile, in sweet pea (Lathyrus odoratus) seeds induces skeletal
deformities and
aortic rupture, probably by interfering with normal maturation of
collagen fibres.
Neurolathyrism in man may be caused by beta-N-oxalyl-L-
alpha,beta-diaminopropionic acid, a
neurotoxin recently identified in Lathyrus sativus seeds.
Histamine,
tyramine,
noradrenaline,
serotonin and other pressor
amines occur in fruits and fermented foods such as bananas, pineapples, cheese and wine. Consumption of such foods by patients taking
monoamine oxidase-inhibiting drugs (e.g.
tranylcypromine) may produce serious
hypertensive crises. Cycad nuts, widely used as human food in tropical and subtropical areas, contain a potent
carcinogen, methyl azoxymethanol, which is more or less removed prior to use by leaching in water. Consumption of plants of the onion, cabbage and cress families introduces into the body such toxic chemicals as
benzyl cyanide,
goitrin and
thiocyanates. The lachrymatory substance in onions is propenyl
sulfenic acid.