What sort of blood work have you had done? More than likely you are not making what's called secretory IgA or seen as S-IgA. This is the antibody that mixes in the mucous and protects all the mucous membranes. I personally believe it is a regulator of what food, pollen (in the nose) and other toxins, passes through the mucous membrane to the blood stream and when. Ther are many other factors besides S-IgA, but if you don’t make secretory IgA (it is the most common deficiency of the immune system) then there is little regulation and it becomes “free game” for everything to pass through to the blood stream before it is properly digested, and major reactions can occur.
Also, depending on your genetics, you may also have problems making an important antioxidant called glutathione. I have genetic abnormalities (along with a lack of secretory IgA) and have great difficulty making it from three essential amino acids I get in my diet. Without taking the supplement I do not clear free radicals and wind up feeling weak all the time. I buy mine from http://www.allstarhealth.com/f/now-glutathione_500mg.htm because it’s good and the least expensive I’ve found. You must take it on an empty stomach. Any foods will prevent absorption since it’s a macromolecule. Wait about 20 to 30 minutes before having a meal. You’ll be amazed how much it will help.