Community surveys have been conducted to assess the prevalence of food sensitivity as
by the participants. Estimates vary between 1 and 40 per cent but the true prevalence is likely
be small. Unfortunately, it is not possible to say how much smaller because this would require
large-scale and expensive investigations involving detailed clinical histories, elimination diets
where various foods are omitted from the diet, and challenges with the substances thought to
cause the reactions. In many scientific studies patients have given histories consistent with
sensitivities to particular foods, but when a food has been given in disguised form so that it is
longer recognisable, only a small proportion of patients actually show an adverse reaction.
Nevertheless, sensitivities to various foods (for example, fruits and vegetables, nuts, fish) and
food components (for example, salicylates, amines and sulphites -
see SULPHUR-FREE DRIED FRUITS ARE HEALTHIER
) showing a wide range of symptoms (skin, gut, respiratory tract,
psychological) have been established, and food sensitivity must be considered as a possibility
when evaluating many medical disorders.