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A Balanced Risk–Benefit Analysis to Determine Human Risks Associated with Pyrrolizidine Alkaloids (PA)—The Case of Tea and Herbal Infusions

Faculty of Medicine, LMU—University of Munich, 80333 Munich, Germany
Didactics of Mathematics, University of Regensburg, 93053 Regensburg, Germany
Centre for Clinical Studies, University Hospital Regensburg, 93042 Regensburg, Germany
General Medicine Unit, University Hospital Regensburg, 93053 Regensburg, Germany
Institute of Evidence-based Dietetics, University of Applied Sciences Neubrandenburg, 17033 Neubrandenburg, Germany
Author to whom correspondence should be addressed.
Nutrients 2017, 9(7), 717;
Received: 29 May 2017 / Revised: 28 June 2017 / Accepted: 3 July 2017 / Published: 7 July 2017
PDF [935 KB, uploaded 7 July 2017]


Humans are exposed to pyrrolizidine alkaloids (PA) through different sources, mainly from contaminated foodstuff. Teas and herbal infusions (T&HI) can be contaminated by PA producing weed. PA can possess toxic, mutagenic, genotoxic, and carcinogenic properties. Thus, possible health risks for the general population are under debate. There is a strong safety record for T&HI and additionally epidemiological evidence for the preventive effects of regular tea consumption on cardiovascular events and certain types of cancer. There is no epidemiological evidence, however, for human risks of regular low dose PA exposure. Recommended regulatory PA-threshold values are based on experimental data only, accepting big uncertainties. If a general risk exists through PA contaminated T&HI, it must be small compared to other frequently accepted risks of daily living and the proven health effects of T&HI. Decision making should be based on a balanced riskbenefit analysis. Based on analyses of the scientific data currently available, it is concluded that the benefits of drinking T&HI clearly outweigh the negligible health risk of possible PA contamination. At the same time, manufacturers must continue their efforts to secure good product quality and to be transparent on their measures of quality control and risk communication. View Full-Text
Keywords: pyrrolizidine alkaloids (PA); risk–benefit analysis; tea and herbal infusions pyrrolizidine alkaloids (PA); risk–benefit analysis; tea and herbal infusions

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Habs, M.; Binder, K.; Krauss, S.; Müller, K.; Ernst, B.; Valentini, L.; Koller, M. A Balanced Risk–Benefit Analysis to Determine Human Risks Associated with Pyrrolizidine Alkaloids (PA)—The Case of Tea and Herbal Infusions. Nutrients 2017, 9, 717.

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