The availability and cost of a milk-free diet for cow's milk protein allergy

Background:  Cow's milk protein allergy (CMPA) is the most common food allergy, and adherence to a milk-free diet is essential, particularly in immunoglobulin E-mediated CMPA sufferers (Benhamou et al., 2009). No studies have looked into the practical aspects of a milk-free diet. The aim of this project was to evaluate how the availability and cost of a milk-free diet compares with that of one containing cow's milk protein.

Methods:  A cross-sectional survey was conducted in the London Borough of Harrow and three major superstores in an urban setting (inclusion criteria of ≥25 000 sq ft) were randomly selected. Two shopping baskets were created; basket A with commonly consumed foods (bread, biscuits, milk, packaged fruit/vegetable salads, and ready meals which contained ≥12% protein from nondairy protein sources) based on the Eatwell plate (Food Standards Agency, 2007), and basket B with their cow's milk-free alternatives. The price and number of varieties were recorded and analysed for each food group per basket. Pearson's chi-squared and Wilcoxon-rank sum tests were conducted for availability and cost of each food type in both baskets.

Results:  The availability of foods suitable for a CMPA diet (basket B) was lower than basket A: 74% bread, 15% biscuits, 26% milk and 25% ready meals compared to 26%, 85%, 74% and 75%, P-values of 0.001, 0.002, 0.001 and 0.005, respectively. The availability of fruit/vegetable salads was not statistically significant between the two baskets. Regarding cost, bread in basket A was found to be significantly more expensive than in basket B, whereas milk substitutes (all superstores) and ready meals (superstore 2 only) were significantly more expensive in basket B (Table 1). The cost of biscuits and fruit/vegetable salads between the two baskets was not significantly different.