Soy-Based Infant Formula: Are Phyto-Oestrogens Still in Doubt?

Area of Science:

• Pediatric Nutrition
• Endocrinology
• Developmental Pediatrics

Background:

• Soy-based formula (SF) use in infants exceeds recommendations, often driven by perceived long-term health benefits.
• Concerns persist regarding the safety of SF, particularly the impact of phytoestrogens on infant development.
• Existing research on SF safety yields conflicting results, necessitating a comprehensive review.

Purpose of the Study:

• To review current knowledge on the effects of phytoestrogens in soy-based formula on early and late child development.
• To evaluate the safety of soy-based formula for infant nutrition based on available scientific literature.

Main Methods:

• A narrative review of studies published from January 1980 to June 2017.
• Literature search conducted using PubMed with keywords: "soy," "soy formula," "child," "phytoestrogens."

Main Results:

• Analysis suggests modern soy-based formulas are not associated with significant abnormalities in overall human development.
• Conflicting results exist regarding the impact of SF on sexual, neurobehavioral, immune, and thyroid functions.
• Children with congenital hypothyroidism require specific thyroid function monitoring when using SF.

Conclusions:

• Current evidence indicates that soy-based formula is generally safe for infant nutrition regarding long-term development.
• Phytoestrogen effects from SF require ongoing research, but major developmental abnormalities are not widely observed.
• Close monitoring of thyroid function is crucial for infants with congenital hypothyroidism using soy-based formula.