Back in 1987 or 88 I saw Dr Chris Reading who had a mixed “Orthomolecular” medical practice in the Northern Beaches area of Sydney. I actually give him credit for what is now called the Autoimmune Protocol (AIP). No nightshades, no legumes, no gluten or casein… Sarah Ballantyne, Ph.D. (AKA The Paleo Mom) explains here, 30 years later, why we don’t eat nightshades.

Tomatoes, potatoes, eggplants, sweet and hot peppers (but not black pepper), and chili-based spices (including paprika) all come from plants which are members of the nightshade family. Nightshades can be problematic for many people due to their lectin, saponin and/or capsaicin content. They tend to be even more problematic for those with autoimmune disease and …Read More

Source: The WHYs behind the Autoimmune Protocol: Nightshades ~ The Paleo Mom