Wheat and other grains like maize (corn), barley, sorghum and rice, as well as potatoes, are among the most important staples of the human diet. Legumes, tomatoes, nuts and seeds, as well as dairy products, provide a whole bunch of essential and other nutrients, many of which can help us combat chronic diseases. Most people are aware that a lot of us, actually around one-fifth of Westerners, are intolerant to gluten in wheat and other grains, and that over 80% of some populations, especially some Asian ones, may be intolerant to some degree of lactose in dairy. But few recognise that grains or cereals, legumes (especially peanuts and unfermented soya) and dairy, contain a group of proteins called lectins that can wreak havoc on the digestive systems of some.
Lectins are naturally-occurring plant proteins that owe their existence to protecting the plant from insect pests and plant diseases. They are the proteins in red kidney beans that can poison you if you don’t cook them. Lectins, as a group, are in no way alien to our diet and, at the low level of exposure, which was the norm prior to the arrival of agriculture some 12,000 years ago, they have positive effects on health. This includes their role in immune function, cell growth, cell death, and body fat regulation.