ABC News: Rat Study Shows Dirty Better Than Clean:
"WASHINGTON Jun 16, 2006 (AP)— Gritty rats and mice living in sewers and farms seem to have healthier immune systems than their squeaky clean cousins that frolic in cushy antiseptic labs, two studies indicate. The lesson for humans: Clean living may make us sick.
The studies give more weight to a 17-year-old theory that the sanitized Western world may be partly to blame for soaring rates of human allergy and asthma cases and some autoimmune diseases, such as Type I diabetes and rheumatoid arthritis. The theory, called the hygiene hypothesis, figures that people's immune systems aren't being challenged by disease and dirt early in life, so the body's natural defenses overreact to small irritants such as pollen."
Grains can mimic all kinds of natural body reactions, and can promote an immune system attack. Living in a super clean environment may make it easier for sub threshold threats to the immune system to promote a more aggressive response. Also, lack of omega3 encourages inflammation, which is the state of the body when it is fighting infection.