Risks for human health related to the presence of plant lectins in food

The European Commission asked the European Food Safety Authority (EFSA) to assess the risk related to the presence of plant lectins in food. Based on the available evidence, the CONTAM Panel considered only phytohaemagglutinin (PHA), a legume lectin from beans (Phaseolus sp.), for the risk characterisation. Effects of PHA in the small intestine were considered as the critical effect in subacute studies in rats. A lower confidence limit of the benchmark dose (BMDL)10 of 22.9 mg/kg body weight (bw) per day for an increase in small intestine dry weight was selected as the most appropriate reference point for the risk characterisation. The establishment of a health-based guidance value for PHA was not considered appropriate due to the limitations and uncertainties in the current toxicological evidence, and the margin of exposure (MOE) approach was used for the risk characterisation. The Panel considered that acute exposure resulting in MOEs above 100 is not expected to raise a health concern. As no occurrence data were submitted to EFSA, data for PHA presence in food were identified by a literature search. An arbitrary acute exposure scenario, where only 50% of the lectins are inactivated due to insufficient cooking of food containing lectins (e.g. beans), would result in MOEs below 100. The Panel, accounting for the uncertainties affecting the exposure and hazard assessments, concluded with at least 95% probability that such a dietary exposure would raise health concerns. The Panel also noted that exposure to completely deactivated lectins in food prepared following adequate food processing practices (e.g. soaking and boiling) would not raise health concerns. No risk characterisation could be performed for other lectins due to the lack of relevant toxicological data and/or in some cases lack of occurrence data.