Do you love beans but always prepare them in a hurry? A new scientific opinion from EFSA (European Food Safety Authority) highlights an aspect of the preparation of legumes that many underestimate, but which can have significant consequences on our health.
The mistake to absolutely avoid
The problem concerns the inadequate cooking of beans and other legumes that contain thermolabile lectins. When these foods are not prepared correctly – skipping the soaking or reducing boiling times – those natural proteins, called lectins, remain active, which in certain conditions can be toxic to the body.
EFSA focused its evaluation in particular on phytohemagglutinin (PHA), a lectin present in beans of the Phaseolus genus (such as kidney beans, pinto beans and lima beans), considered the most problematic among those contained in commonly consumed plants.
What are lectins
Lectins are proteins naturally present in many plants where they perform a defense function against parasites and pathogens. In most cases they do not represent a problem for human health, but some varieties, if ingested in significant quantities and in active form, can cause disorders.
The most common symptoms related to eating undercooked legumes include nausea and vomiting, abdominal pain and diarrhea. These disorders can appear even a few hours after ingestion and, according to studies conducted on animals, the small intestine is the organ most affected by the action of active lectins.
EFSA experts have developed an acute exposure scenario based on insufficient cooking, in which around 50% of the lectins still remain active. This situation could occur when:
The evaluation concludes that lectins may be a problem for all age groups. The risk, therefore, does not only concern children or fragile people, but the entire population.
How to prepare legumes safely
The good news is that the risk is avoidable by following the correct preparation procedures. EFSA confirms that lectins can be effectively deactivated through appropriate home treatments.
The correct procedure includes:
This process usually ensures a 90-100% reduction in lectin activity, making legumes completely safe for consumption.
EFSA highlights that some alternative cooking methods, increasingly popular in modern kitchens, are less effective in neutralizing lectins. These include microwave cooking, steam cooking without preliminary boiling, roasting and slow cooking at low temperatures.
These methods can be used, but only after adequate soaking and a thorough boiling step.
The European Commission’s request to EFSA to assess this risk arises from cases of food-borne illnesses associated with the consumption of inadequately cooked legumes. According to the Authority, this phenomenon could be linked to the growing diffusion of “raw” or plant-based diets with minimal preparations, where cooking is reduced in an attempt to preserve nutrients.
Based on EFSA’s scientific advice, the European Commission and Member States will now evaluate possible measures to inform and protect consumers. The paper also highlights several gaps in the available data and makes recommendations for future studies on the presence of lectins in foods and their long-term effects.
In any case, legumes remain exceptional foods from a nutritional point of view, rich in vegetable proteins, fibre, vitamins and minerals. There’s no reason to eliminate them from your diet, you just need to prepare them the right way.
