We get asked some interesting and often challenging questions at our market stall on Sundays. One that comes up more and more is which nuts are low in lectins. Once I had done some research as to what lectins even are, I found it an interesting topic to share here...
Lectins are essentially proteins that are present in all plants and plant seeds. They play an important role, as far as the plant is concerned, in that they deter animals from wanting to eat them. They do this by binding to carbohydrate molecules in the cell membranes in the animal's gut. This causes irritation for the keen plant eater, which then makes it somewhat less keen to eat that plant again in the future.
Biology being the amazing thing that it is, the human gut has developed some cunning ways of dealing with these proteins - otherwise, how would we have lived and eaten on the planet for several million years? We have a lining on our gut coated with a protective barrier that neutralises plant lectins. But... high concentrations of lectins can still get through and cause damage, especially to people with food sensitivities.
Problematic lectins can be found mostly in grains (especially wheat and corn); beans/legumes; nightshade vegetables (i.e. tomatoes, potatoes, eggplant, capsicum);.... and.... Tree nuts!
The potential impact of lectins on the human digestive system was first publicised by Dr. Stephen Gundry, who wrote the best-selling book The Plant Paradox all about the subject, with dietary guidelines as well. Check out his website for more information and his complete 'YES' and 'NO' lists.
All is not lost for all us avid nut lovers however.... For one thing, the soaking that is part of the activation process does reduce the amount of lectins present. And secondly, not all nuts are equal on the lectin front. Dr. Gundry puts the following nuts on the 'YES' list (up to half a cup per day):
- Pistachios
- Brazil nuts
- Walnuts
- Sesame Seeds
- Hazelnuts
- Hemp Seeds
- Macadamias
- Pecans
(Almonds are out because of the lectins in their skin, unfortunately).