To throw light on this problem we have admitted patients, thought for one reason or another to be reacting adversely to foods, to a hostel unit where they have first been fasted for four days on spring or filtered water, and have then been given single foods one by one so that adverse reactions to them might be recorded by both the patient and the physician. The patients studied had for the most part a combination of symptoms which included nasal stuffiness, headaches, irritable bowel syndrome, arthralgias, eczema, and neurological problems such as depression and lassitude. 33 patients have been investigated so far. When foods were reintroduced the reactions were unexpected, both by the patient and by the attending physician, for neither knew beforehand that foods, let alone which food, were precipitating symptoms. Had the patient been aware that foods were playing a part in causing his symptoms he would have avoided them.
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. 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.