Why Are Lectins Often In Seeds and Skins?
From looking at many food tests on lectins, a lot of research shows lectin activity in the seeds and skins part of the plant.
Sometimes, there is no lectin activity in other parts of the food tested. One such example is dates, where in one test, lectins were found in the seed but not the fruit.¹
Also, plenty of foods thought of as grains and legumes are actually seeds. One example is beans. Beans are seeds. Plenty of beans have shown lectin activity in testing and are possibly the highest quantity of lectins measured.
For example one study showed black beans having 26,429 ± 5603 HAU/g.²
So why is it that lectins are often in seeds and skins?
First let’s consider seeds. Seeds are needed in order for a fruit to reproduce. The seed bears the fruit. In fact, a fruit is basically that which bears after it’s own seed.
Lectins are thought to be natural “pest repellents” that deter animals and bugs from eating the plants.
Seeds have mechanisms, if you want to call them that, that protect the seeds. For example, animals can eat seeds and then often times, poop them out. The seed is preserved, such that when the animal poops them out, the seeds can still germinate and grow into a plant!
That being said, if you think about it, it makes sense that the skin and seeds would contain high amounts of lectins.
The skins are the outermost part of the food, so the first thing that would be touched when eaten, for example by an animal or bug.
The seeds are the most important part to the reproduction of the plant, in the sense that the seed itself can grow into a plant.
Even things like stems and leaves have been found to have lectin activity in research, usually stems more so than leaves.
Again, this makes sense when you consider that without the stems of the plant, it would be hard to grow, but the stems can always grow more leaves.
The leaves are by logic more edible than the stems.
It certainly seems that, more often than not, the more important parts of the edible plant, in terms of protection and reproduction, contain more lectins.
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