Lectins in plant-based foods: Is there a health risk?
What it's about:
Many plant foods contain so-called lectins. They fulfil important functions in the plant by protecting it from diseases and pests. When consumed in moderation, most lectins are not expected to have any adverse effects on human health. However, ingesting certain lectins, which are mainly found in raw pulses, can lead to health impairments, including symptoms such as nausea, vomiting and diarrhoea. Children are particularly at risk due to their low body weight.
To avoid the undesirable effects, it is usually sufficient to follow the recommended preparation methods for pulses. Since the lectin activity is destroyed by high heat, the following applies: cook fresh beans in boiling water for at least 30 minutes. Dried pulses should be soaked for at least five hours and then boiled in fresh water, after pouring away the soaking water. Gentle cooking methods such as steaming or stewing are not suitable for most pulses. Sugar snap peas and peas are an exception, as they contain only low amounts of lectins. They can even be eaten raw in moderation. This also applies to many other foods that contain lectins, including tomatoes, mushrooms and bananas.
Under no circumstances should plant-based foods be avoided in favour of a low-lectin diet. A diet with a varied selection of fruits and vegetables (including pulses in a sufficiently cooked form) provides, among other things, valuable vitamins, minerals and dietary fibre.
As the adverse effects of lectins are mainly due to improper preparation of pulses, the Federal Institute for Risk Assessment (BfRshort forGerman Federal Institute for Risk Assessment) recommends to intensify risk communication: Packaged foods such as dried pulses or fresh green beans can be labelled to indicate that they should only be consumed if they are sufficiently cooked.
In view of the expected increase in plant-based diets and the possible toxic and, in some cases, allergenic potential of certain lectins, the BfRshort forGerman Federal Institute for Risk Assessment also considers the further development of efficient and standardised detection methods for lectins in food to be desirable.