On request from the European Commission following an application by Dairy Goat Co-operative (NZ) Ltd, the Panel on Dietetic Products, Nutrition and Allergies was asked to provide a scientific opinion on the suitability of goat milk protein as a source of protein in infant formulae and in follow-on formulae.
In 2004, the Panel issued, on request of the European Commission, a scientific opinion related to the evaluation of goat milk protein as a protein source for infant formulae and follow-on formulae, followed by a statement in 2005, and concluded that there was insufficient evidence to establish the suitability of goat milk as a protein source in infant formulae.
For the present evaluation, compositional data of an infant and a follow-on formula made from whole goat milk that retained the natural whey-to-casein ratio of goat milk, data from a double-blind, randomised, controlled, three-centre trial, and a re-analysis of the data of the trial which formed the basis of the Panel’s previous evaluation were submitted.
The Panel notes that there are compositional differences between goat and cow milk, which need to be taken into account in the manufacture of infant and follow-on formulae, particularly in the composition of caseins.
Cow milk allergy is the most frequent allergy in the first years of life and there is a high risk of cross-reactivity with goat milk protein in clinical studies, but also selective allergy to goat milk proteins only has been reported. The Panel notes that goat milk protein can induce allergic reactions. Currently, there are insufficient data available on the allergenicity of goat milk protein and it is not possible to predict the incidence and severity of adverse reaction to goat milk protein as a result of the proposed use. There are no convincing data to support that the incidence of allergic reactions is lower when feeding goat milk-based infant formula compared with cow milk-based infant formula.
A multicentre, randomised, double-blind controlled trial to compare growth rates and nutritional status of infants with exclusive feeding of infant formula based on goat milk (n=101) or cow milk (n=99) for at least four months, and continuous feeding of the formula up to 12 months in addition to complementary food, was performed between April 2008 and April 2009 in newborn infants recruited in three hospitals in Adelaide. An exclusively breast-fed reference group was included (n=101). The baseline characteristics of the participants were comparable between the two formula groups, except that in the goat milk formula group more mothers smoked during pregnancy. Breast-fed infants had a higher mean birth weight, lower maternal pre-pregnancy body mass index (BMI), lower percentage of smoking mothers and more parents with a higher level of education. Daily median intake of study formulae was not different between formula groups until four months of age.
There were no statistically significant or clinically relevant differences in weight, length or head circumference development between the two formula groups from registration to four months or from registration to 12 months. Differences in blood biochemistry between the two formula groups, which were significant for urea and folate, reflect differences in formulae composition but do not raise concern with respect to the safety and/or nutritional adequacy of the formulae. Some differences in indispensable amino acid (L-isoleucine, L-threonine, L-phenylalanine and L-valine) levels were also observed between the formula groups but none of the levels are considered to be of clinical significance.
There was no difference in the occurrence of serious adverse events in the two formula-fed groups of infants during the 12 months.
There were small differences in linear and ponderal growth parameters between infants from the two formula groups compared to a parallel group of exclusively breast-fed infants also after adjustment for the higher birth weight of breast-fed infants in this study. The differences, expressed in WHO z scores, were small (<0.5 z-scores). The differences became smaller during the second half of the first year of life. When breast-fed infants were compared to formula-fed infants, urea levels were higher in the latter, while folate levels were lower in the goat milk formula group but within the normal range, which reflects the higher protein intake in the formula-fed infants and the lower folate content of the goat milk formula. Observed differences in plasma levels of some amino acids between formula- and breast-fed infants are most likely explained by the higher protein intake of the formula-fed infants compared to the breast-fed infants.
The Panel notes that the goat milk formula administered in this study complied with the compositional criteria of Directive 2006/141/EC. Follow-up until 12 months showed similar growth patterns in both formula groups. The growth pattern of formula-fed infants differed, as expected, from that of the WHO growth standard in particular with respect to weight-for-length. The biochemical parameters reflected what is known about the difference between formula and human milk feeding. The Panel considers that the study provides sufficient evidence to conclude that goat milk can be a suitable source of protein for use in infant and follow-on formulae.
The Panel also considered the re-analysis provided by the applicant of the data of the trial which formed the basis of the Panel’s earlier evaluation. The Panel notes that the re-analysis of the data does not change the Panel’s earlier conclusion that the sample size was insufficient to conclude that the goat milk formula was as safe and nutritionally adequate as cow milk formula. The Panel, however, also notes that the results of this study with respect to similarities in growth patterns and in the occurrence of adverse events between the goat and cow milk formula groups, as well as with respect to differences in growth between formula and breast-fed infants, are in conformity with the results of the multicentre trial described above.
The Panel has no data on which to base a conclusion on the safety and suitability of the follow-on formula manufactured with unmodified goat milk described in the dossier. However, given the similarity in composition of the goat milk infant and follow-on formulae, the fact that the infant formula was consumed throughout the first year of life, instead of follow-on formula, and the fact that the follow-on formula fulfils the compositional criteria laid down in Directive 2006/141/EC, the Panel considers that goat milk protein is a suitable protein source for follow-on formula in older infants who receive it in addition to complementary food.
The Panel concludes that protein from goat milk can be suitable as a protein source for infant and follow-on formulae, provided the final product complies with the compositional criteria laid down in Directive 2006/141/EC.
For goat milk protein to be used in infant and follow-on formulae, particular attention has to be given to the protein content and composition of the milk proteins, and to the amino acid content, which should in the final product be in compliance with Directive 2006/141/EC, if necessary by the addition of free amino acids in appropriate amounts.