Quinolizidine alkaloids (CA) are alkaloids produced mainly in lupins from lysine in the green tissue of the plant and stored in all plant parts, including seeds. These secondary metabolites of the plant serve it as defense against pathogens and as protection against feeding. There are over 170 known quinolizidine alkaloids in a wide variety of lupine species. Depending on botanical and geographical origin, soil composition and climate, the levels of quinolizidine alkaloids vary. These alkaloids can cause poisoning in humans with symptoms ranging from dizziness, confusion, palpitations, nausea, dry mouth, and loss of motor control to cardiac arrest and respiratory paralysis.
Quinolizidine alkaloids such as lupanine, lupinine and sparteine are mainly present in lupins. Lupins are used as feed and green manure, as well as food and ornamental plants.
Lupine seeds can be classified into bitter lupine seeds (high content) and sweet lupine seeds (low content) based on their alkaloid content. As food and feed, mainly sweet lupins are used, since the alkaloid content of these has been reduced by means of breeding. The wild forms, so-called bitter lupins, have high amounts of quinolizidine alkaloids. Technical debittering is possible by pretreatment, but there is a risk that lupins may be insufficiently debittered and thus continue to cause poisoning.
In recent years, the lupine has become increasingly popular in vegetarian, vegan or gluten-free diets due to its high protein content. For example, the following lupine products are available: lupines in meat substitutes, in milk substitutes (e.g. ice cream, yogurt...), spreads, baked goods, pasta, beverages, coffee substitutes and snacks (e.g. tremoços) and lupine flour.
In Austria, the narrow-leaved or blue lupin(Lupinus angustifolius) and the white lupin(Lupinus albus) are used agriculturally. Legumes live in symbiosis with nitrogen-fixing root nodule bacteria and thus improve soil quality by fixing nitrogen, which is why lupins are also used as green manures.
Cases of poisoning by lupine seeds do not occur frequently, but nevertheless pose a serious risk to the people affected. There are few documented cases of lupine seed poisoning, and children are more likely to be affected than adults. The most serious documented cases of poisoning date from the 1970s: three children aged 10 years, 1.5 years, and 17 months died after eating lupine seeds. The alkaloid dose of these described poisoning cases was in the range of 11 - 25 mg/kg body weight. It is currently believed that doses of 10 mg or more of lupin alkaloids per kilogram of body weight could have fatal consequences. Cases of poisoning due to the consumption of industrially produced lupin products are not known (BfR, 2017, EFSA, 2019).
Situation in Austria
There are currently no maximum levels for quinolizidine alkaloids in food.
We are investigating quinolizidine alkaloids in various foods: Focus action quinolizidine alkaloids in products containing lupine - Monitoring.
- Pay attention to the bitter taste of lupine seeds, this is an indication of the undesirable alkaloids.
- Do not consume the bitter tasting soaking water of lupine seeds or use it for food preparation, but drain and rinse the lupines with fresh water.
- Use industrially produced lupine products, as alkaloid-poor varieties such as sweet lupines are used for this purpose.
- Refrain from using debittered bitter lupin seeds as a precaution. The debittering process may not be sufficient to reduce the undesirable alkaloids
The European Food Safety Authority (EFSA) published a scientific opinion regarding CA in feed and food in 2019. Due to a lack of information regarding the intake level of lupin alkaloids at which no adverse effects occur, EFSA could not derive a safe dose for consumption. Therefore, the margin of exposure approach was chosen for a risk assessment. According to the derivation of EFSA, acute pharmacological (antiarrhythmic) effects occur from 0.16 mg sparteine /kg body weight. Consequently, EFSA concludes that the intake of lower amounts than 0.16 mg/kg body weight of lupine alkaloids do not indicate any health concern.
Regarding chronic intake, no health-based guidance value could be derived either due to lack of data (EFSA, 2019).
More information on quinolizidine alkaloids
EFSA, 2019: Scientific opinion on the risks for animal and human health related to the presence of quinolizidine alkaloids in feed and food, in particular in lupins and lupin‐derived products. EFSA Journal 2019;17(11):5860. DOI 10.2903/j.efsa.2019.5860
Last updated: 10.10.2023