Exposure to pyrrolizidine alkaloids in food, in particular through frequent and high use of tea, herbal tea and supplements, is a possible long-term concern for human health due to their potential carcinogenicity, say scientists at the European Food Safety Authority (EFSA).
The consumption of food supplements based on pyrrolizidine alkaloid-producing plants could also result in exposure levels causing short-term toxicity resulting in adverse health effects, says the Authority.
EFSA has updated its 2011 advice on the risks for human and animal health from pyrrolizidine alkaloids, a large group of toxins produced by particular plant species, including those that adventitiously enter the food chain.
The European Commission requested the updated risk assessment, which takes account of exposure estimates using more recent data on the levels of these toxins in honey, tea, herbal infusions and food supplements.
In 2011 EFSA concluded there were possible long-term health concerns for toddlers and children who are high consumers of honey, the only food category for which sufficient data were then available.
EFSA’s experts identified 17 pyrrolizidine alkaloids in food and feed that they said should continue to be monitored. They also recommended further studies on the toxicity and carcinogenicity of those most commonly found in food.
In 2016, acting on newly available data from EFSA data on PAs, Germany’s national institute for risk assessment BfR advised consumers vary the source of at risk products they consume, to minimise risk of exposure to products with high PA levels. The organisation said that the foods likely to contribute most to PA intakes for both children and adults were herbal teas, black tea and honey – with dietary supplements being an additional source for adults.
In line with EFSA opinion, BfR says that the main concern with PAs is the effect of regular, long-term exposure “which could pose a risk to children and adults). It concluded that “there is no acute risk”.
• Pyrrolizidine alkaloids (PAs), sometimes referred to as necine bases, are a group of naturally occurring alkaloids based on the structure of pyrrolizidine. Pyrrolizidine alkaloids are produced by plants as a defense mechanism against insect herbivores. More than 660 PAs and PA N-oxides have been identified in over 6,000 plants, and about half of them exhibit hepatotoxicity.
Unsaturated pyrrolizidine alkaloids are hepatotoxic, that is, damaging to the liver. PAs also cause hepatic veno-occlusive disease and liver cancer. PAs are tumorigenic. Disease associated with consumption of PAs is known as pyrrolizidine alkaloidosis.
Read a ‘Choosing responsible suppliers is the best way to ensure a delicious, safe cuppa – not playing brand Russian roulette’ (a response to the article above from Pukka Herbs) here.