Contamination of grain with 1,2-dehydropyrrolizidine
ester alkaloids (dehydroPAs) and their N-
oxides is responsible for large incidents of acute and subacute
food poisoning, with high morbidity and mortality, in Africa and in central and south Asia.
Herbal medicines and teas containing dehydroPAs have also caused fatalities in both developed and developing countries. There is now increasing recognition that some staple and widely consumed foods are sometimes contaminated by dehydroPAs and their N-
oxides at levels that, while insufficient to cause acute
poisoning, greatly exceed maximum tolerable daily intakes and/or maximum levels determined by a number of independent risk assessment authorities. This suggests that there may have been cases of disease in the past not recognised as resulting from dietary exposure to dehydroPAs. A review of the literature shows that there are a number of reports of
liver disease where either exposure to dehydroPAs was suspected but no source was identified or a dehydroPA-aetiology was not considered but the symptoms and pathology suggests their involvement. DehydroPAs also cause progressive,
chronic diseases such as
cancer and
pulmonary arterial hypertension but proof of their involvement in human cases of these
chronic diseases, including sources of exposure to dehydroPAs, has generally been lacking. Growing recognition of hazardous levels of dehydroPAs in a range of common foods suggests that physicians and clinicians need to be alert to the possibility that these contaminants may, in some cases, be a possible cause of
chronic diseases such as
cirrhosis,
pulmonary hypertension and
cancer in humans.