Longitudinal evaluation from birth to adolescence of soy protein–based infant formula compared with cow milk–based formula and breastfeeding: A comprehensive summary of findings

Authors: DA CRUZ, LARISSAL - University Arkansas For Medical Sciences (UAMS); SHLISKY, JULIE - Virginia Tech; BELLANDO, JAYNE - University Arkansas For Medical Sciences (UAMS); CHEN, JIN-RAN - University Arkansas For Medical Sciences (UAMS); EDWARDSTIM, EDWARDS - Arkansas Children'S Nutrition Research Center (ACNC); FIECKE, CHELSEY - University Arkansas For Medical Sciences (UAMS); LARSON-PRIOR, LINDA - University Arkansas For Medical Sciences (UAMS); MCCORKLE, LANA - Arkansas Children'S Nutrition Research Center (ACNC); MOORE, MARY BETH - University Arkansas For Medical Sciences (UAMS); SLATON, CHAYLA - University Arkansas For Medical Sciences (UAMS); SOBIK, SARAH - Arkansas Children'S Nutrition Research Center (ACNC); THAKALI, KESHARI - Arkansas Children'S Nutrition Research Center (ACNC); WHITESIDE, MARA - Arkansas Children'S Nutrition Research Center (ACNC); ANDRES, ALINE - Arkansas Children'S Nutrition Research Center (ACNC)

Submitted to: Advances in Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/2/2026
Publication Date: 7/1/2026
Citation: Da Cruz, L., Shlisky, J., Bellando, J.B., Chen, J., Edwardstim, E., Fiecke, C., Larson-Prior, L., Mccorkle, L., Moore, M., Slaton, C., Sobik, S., Thakali, K., Whiteside, M., Andres, A. 2026. Longitudinal evaluation from birth to adolescence of soy protein–based infant formula compared with cow milk–based formula and breastfeeding: A comprehensive summary of findings. Advances in Nutrition. 17(7):1-15. https://doi.org/10.1016/j.advnut.2026.100669.
DOI: https://doi.org/10.1016/j.advnut.2026.100669

Interpretive Summary: More than 50% of infants in the United States are fed infant formula at one point in their life. The most common infant formula type is Cow milk based formula. When breastfeeding and this type of formula is not feasible, soy-based infant formula is the recommended alternative, yet many parents wonder whether this choice affects their child’s long-term health. To better understand this, researchers followed children from infancy (around 600 children) to age 14 ( around 200 adolescents) and compared those who were fed soy-based infant formula, cow’s milk based infant formula, or breast milk. Overall, the results suggest that soy infant formula feeding in infancy does not negatively impact growth, body composition, cardiovascular, gut and skeletal health, metabolism, cognition and language skills or puberty by early adolescence. These results can guide health professionals when prescribing the type of infant feeding according to the child's health needs, parental choices, and the long-term health outcomes of children.

Technical Abstract: Breastfeeding is widely recognized as the gold standard food for infants. However, many families use infant formulas, including soy-based products, which have not been studied for their long-term safety and developmental effects. The Beginnings Study and the Beginnings Follow-Up Study represent one of the most comprehensive prospective cohorts designed to examine how early infant feeding is related to growth, body composition, cardiovascular, microbiome, and skeletal outcomes, neurodevelopment, and reproductive maturation through adolescence. Conducted in Arkansas, United States, the study enrolled 600 healthy, term infants fed soy-based infant formula, cow milk–based infant formula, or human milk during infancy (200 per group). Of these, 385 participants (73.2%) completed the 6-year visit, and 190 (31.7% of enrolled and 49.4% of 6-year visit completers) participated in the 14-year Follow-Up Study. Breastfeeding was associated with slower weight gain velocity during infancy, and consistent lower BMI, fat mass index, and waist circumference extending into adolescence, than formula feeding. Formula-fed infants had comparable results with breastfed infants for skeletal mineralization, most neurocognitive parameters, and reproductive organ development. However, cardiovascular autonomic measures, including heart rate and vagal tone, differed by feeding group, with some sex-specific effects. Novel contributions included analyses of the gut microbiome and metabolomics profiles in early life, which revealed distinct dietary signatures, as well as neurodevelopmental assessments using electroencephalography, which highlighted transient differences in language-related brain responses among feeding groups. Together, these results demonstrate more similarities than differences between soy-based infant formula and cow milk–based infant formula in health outcomes and support the lasting benefits of breastfeeding. This evidence can help guide health care professionals in infant feeding recommendations and highlight critical windows to prevent obesity and promote lifelong health.