Mechanism of Food Intolerance
The mechanism of food intolerance involves the production of antigen/antibody complexes which are deposited in the tissues, triggering the release of inflammatory chemicals causing damage and inflammation in that particular tissue. This could be in any part of the body such as for example, the gut, causing IBS symptoms; in the joints, producing symptoms of arthritis; in the head producing migraines etc
The sequence of events is as follows:
- Partially digested foods pass between gut cells into the blood
- These proteins are recognised as ‘foreign’ and food specific IgG are produced in response
- Antigen/ antibody complexes form between the partially digested foods and the IgG antibodies. The symptoms of food intolerance tend to be delayed because this formation of complexes is a gradual process – it does not happen immediately
- Complement and macrophages stimulate inflammation, although complement helps to prevent smaller complexes going on to form larger complexes
- Complement is activated which causes respiratory burst in neutrophils, release of proteolytic enzymes, mast cell mediators and vasoactive peptides, and aggregation of platelets
- The complexes are deposited in tissues (could be anywhere in body such as gut, head, skin etc)
- C2 and C5 (part of the enzyme cascade) can release histamine too
- Macrophages release inflammatory mediators such as interleukin-1, tumour necrosis factor, reactive oxygen species and nitric oxide
(NB The complement system is an enzyme cascade that helps defend against infection)