Here is welcome news for the millions of people who suffer from allergies--and for the many more whose ailments have a hidden allergic cause. Recent medical discoveries reveal that a number of common illnesses may be the result of adverse reactions to food. Many people suffer for years from maladies as diverse as migraines, stomach ulcers, diarrhea, nausea, constipation, water retention, aching joints, and eczema; others have more serious ailments, such as rheumatoid arthritis, asthma, depression, and Crohn's disease. Medical researchers have now discovered a link between these illnesses and...