Recent research indicates that egg yolks had nutritional benefits for weaning babies that have been breastfed or fed with infant formula. In a study published in the American Journal of Clinical Nutrition and led by Maria Makrides, 137 mother-infant pairs in Australia were randomly assigned to receive regular eggs, eggs enriched by feeding hens a diet rich in n-3 fatty acids, or no dietary intervention (control group). Prior to the test, and six months later when the babies reach one year of age, blood samples were taken to measure docosahexanaenoic acid (DHA) in red blood cells, iron status an plasma cholesterol.