| Development of peak bone mass, a major determinant of osteoporotic risk, occurs primarily during childhood and adolescence. The goals of this project were to assess the influence of early infant feedings on subsequent bone development; and to help understand how early dietary and nutritional factors may relate to bone mass in early childhood. The study population is a cohort of healthy Iowa infants (n = 469) recruited at birth. Parents of the infants returned mailed questionnaires and three-day diet diaries at 6 weeks, 3 months, and 6 months. Infant's diets were assessed and categorized by consumption of human milk dichotomized (“any” vs. “none”); and by primary nutrient source, i.e., human milk, cow milk-based formula, soy protein-based formula. The type of feeding and the nutrient content of the feedings was related to growth parameters and bone measurements of the same children at approximately 5 years of age. There were 106 exclusions due to gestational age, age at time of bone measurement or incomplete dietary data. Linear multiple regression was used to examine the relationship between bone mineral content (BMC) and bone mineral density (BMD) by human milk consumption status, dichotomized and primary diet type. Statistically significant differences in BMC and BMD were seen with both dietary classifications after adjustment for height, weight and age. Infants who consumed human milk as the primary nutrient source, determined at 6 weeks of age, had significantly greater BMC of the total hip, femoral neck, trochanter, and Ward's triangle; and significantly greater BMD of the trochanter and Ward's triangle (p < 0.05) than infants who consumed cow milk-based formula. Human milk consumers (dichotomized) had significantly greater BMC and BMD of the whole body, total hip, femoral neck, trochanter and Ward's triangle (p < 0.05) than non-consumers. In gender-stratified comparisons, the effect of human milk as a primary nutrient source was evident in pairwise contrasts with cow milk-based formula. The differences were greater in boys than in girls. The results appear biological. The results of this study support the hypothesis that bone mass as measured by BMC, BA, and BMD may be influenced by early diet, specifically human milk. |
