Is an azo-free diet nutritionally superior than one containing azo-dyes?

Abstract

Background: Few data are available in the literature as to whether an additive-free diet is more nutritious when compared to one that contains azo-dyes. The aim of this study was to investigate whether there is a significant difference in the nutritional content of an azo-free diet compared to one that contains azo-dyes. This formed part of an extension of a study that looked at the effect of food additives on behaviour of children (Bateman, 2004).Methods: Azo-dyes [(E102), (E104), (E110), (E122), (E123), 4R (E124), (E127), (E128), (E129), (E131), (E132), (E133), (E142), (E151), (E154), (E155), (E180)] and a preservative [(Sodium benzoate (E211)] were eliminated from the diet of children. The study dietitian advised families on how to avoid foods that contain food colours and preservatives such as those found in certain brands of beverages, sweets, cakes, ice lollies, desserts, jam and crisps. To aid compliance to the diet, suitable alternatives were recommended. The parents of 21 children (11 females) aged 8–9 years completed a 7 day food diary (baseline) before and during week 3 of the diet period. The food diaries were collected and coded for portion sizes by the study dietitian and analysed using CompEat. Nutrient values were compared to the recommended nutrient intake. The data was analysed using SPSS 12 and paired samples t-test (significance level P £ 0.005).Results: There was no significant difference in energy, protein or fat intake between baseline diet and the azo-dye free diet. There was a reduction in the mean intake of carbohydrate (P = 0.000), sugar (P = 0.000), phosphorous (P = 0.005), magnesium (P = 0.002), potassium (P = 0.005), chloride (P = 0.003) and vitamin C (P = 0.002) when an azo-free diet was followed.Discussions: Any dietary manipulation may effect overall nutrient intake. The effect may result in a nutritionally superior diet but this is not always the case (Isolauri et al., 1998). The children in this study showed that eliminating azo-dyes from their diet resulted in their intake of two micronutrients (potassium and magnesium) and one macronutrient (carbohydrate) being below that recommended for their age (Department of Health, 1991).Conclusion: Elimination diets may have a detrimental effect on nutritional intake, even when the food that is eliminated is perceived as unhealthy. Any nutritional manipulation should be made with caution and the resultant diet should be assessed to ensure its nutritional adequacy