'Prevention programmes'--a dietetic minefield.

Abstract

Food allergy and intolerance (FAI) is undoubtedly a controversial subject surrounded by a great deal of publicity. One of the most confusing issues arises when considering the value of allergy prevention programmes. Although prevention strategies have now been extensively studied the results are still inconclusive. In childhood, atopic disorders eg asthma, eczema, dermatitis, urticaria, rhinitis and gastrointestinal related symptoms are relatively common with estimates of their prevalence ranging from two to 20 per cent (Mallet & Henocq, 1992). In addition, the proportion of young children with allergies seems to be increasing, although the extent to which food allergens contribute remains unclear (Hide, 1991; Croner, 1992; DoH, 1994). In many of these cases, prevention of unpleasant, socially and psychologically disruptive and sometimes life threatening symptoms can be achieved by dietary modification. If atopic and gastrointestinal symptoms can be prevented growth failure may not be a problem, children may miss less schooling, and if long term prevention is achieved there may be a substantial reduction in the cost of medical care these children would otherwise require. Before prevention programmes are introduced, however, careful thought should be given to the implications of dietary treatment. The programmes are difficult to administrate in terms of both resources and expense. Specifically, from a nutritional point of view, the diets employed are often socially disruptive which inevitably leads to problems with compliance. Nutritional adequacy may also be difficult to achieve unless there is close supervision by a dietitian who is experienced in the management of the complex dietary manipulations involved. Unfortunately the dietetic resources essential for the safety of the programmes may be lacking in many hospitals. Preventive practice may be aimed at either the general population or at specially identified group who are considered to be at a greater risk of developing atopic disorders. Dietary intervention studies looking at prevention in this 'at risk' group have considered maternal dietary modification during pregnancy and lactation, the use of soya and hydrolysed protein feeds and the weaning diet. The nutritional consequences of these methods of dietary manipulation will be discussed in more detail.