Dairy products

When casein (one of the proteins in dairy) mixes with stomach acid, it produces something called an exorphin. This substance can result in many troubles – brain fog, inability to concentrate, and a numbness to pain, just to name a few.
Dairy is also problematic because it is considered one of the most pro-inflammatory foods in the Western diet, and inflammation has been associated with autism.
Some studies show that people with autism who removed dairy from their diet began talking more, and their hyperactivity was reduced.