Investigations such as these are inexpensive and, when foods are implicated, the treatment, food avoidance, is cheap. When food avoidance prevents headaches, the irritable bowel syndrome, arthralgias, and depression, it is more effective and less costly than traditional treatment, and the observation also throws light on the aetiology of the disorder. A trial of diet revision is safe, practical and effective when the clinical pattern suggests the diagnosis of food allergy or when the patient believes that food is responsible for causing symptoms. It is not necessary to know the precise triggering mechanism or which mediators of inflammation are activated. Such information is difficult to obtain, often requiring considerable laboratory investigation beyond the scope of clinical practice.
Foods seem to play a part in severe chronic disorders which have no recognized aetiology.
To establish the role of foods in precipitating these disorders we need hospital units where patients can be fasted and then tested individual with foods, with biochemical and immunological studies if required. Investigations such as these are inexpensive and, when foods are implicated, the treatment, food avoidance, is cheap. When food avoidance prevents headaches, the irritable bowel syndrome, arthralgias, and depression, it is more effective and less costly than traditional treatment, and the observation also throws light on the aetiology of the disorder. Most physicians will check for anemia and low thyroid first. The measurement of hemoglobin and a stained blood smear are probably the most valuable tests and can be done in most physician's offices - if the hemoglobin is low and the blood smear show small red blood cells then the diagnosis is iron deficiency anemia and the fix is iron supplements.