What is soy-based infant formula ?
Soy formula is an alternative to cow’s milk formula. Soy infant formula products are intended for babies under 12 months old. Soy protein-based formulas in the United States may account for nearly 25% of the formula market.(1)
The use of soy formula is very popular with some parents as they believe that it may reduce colic, prevent allergies, or reduce their child’s risk of disease later in life. Switching baby formulas doesn’t usually relieve these symptoms. There is no evidence supporting the use of soy protein formulae for the prevention or management of infantile colic, regurgitation, or prolonged crying.(3)
Experts say that parents shouldn’t be quick to switch to soy formula over breast milk or cow’s milk formula unless it is medically indicated. (4)
This blog reviews the latest research to determine whether soy formula is safe for your baby.
Comparison with other formulas
According to FDA, all baby formulas are required to fulfill certain criteria regarding their composition, purity, and nutrient content.(5)
Soy-based infant formulas include soy protein isolate with other nutrients. Also they contain the same amount of calories and important nutrients as other types of baby formulas. And hence, they have the same ability to meet a baby’s growth and developmental needs. Infants who suffer from dairy allergy or lactose intolerance may opt for soy infant formulas.(6, 7)
Due to the high amount of isoflavones present in soy based infant formulas (SBIF) the concern regarding its adverse effects are increasing. Babies fed soy formula (SF) receive more soy isoflavones than babies who are breastfed or fed with cow’s milk formula.(7)
Summary
All the baby formulas in regard to nutrition composition and safety measures are strictly regulated. This ensures that all formulas in the market, including soy formulas, equally meet a baby’s growth and developmental needs.
Who should choose soy-based formula?
Although breast milk is the ideal food for infants. But sometimes drinking breast milk is not possible, and for those situations infant formulas are available.
Soy-based infant formula contains soy protein isolates and is fed to infants as a supplement to or replacement for human milk or cow milk.
Soy formula is the best feeding choice for vegan families and babies with specific medical conditions.
It has been used to feed healthy babies safely for more than 100 years with few reports of long-term health problems. In most of the cases, poor or no negative effect has been demonstrated. Thus, it can be considered an appropriate feeding choice for most babies. (1,2)
It is recommended for vegan families or those full term Infants who suffer from dairy allergy or lactose intolerance may opt for the same. But before switching to soy-based formula vegan families and parents of such children should consult a healthcare professional to determine whether a soy-based formula is the best option.
Summary
Soy-based formula may be an appropriate choice for some healthy infants. But it is not an appropriate choice for babies born prematurely, nor those with low birth weights, poor renal function, or a cow’s milk allergy.(6)
Do they provide any health benefits ?
Some parents believe that soy formula use in infancy reduces colic, allergies, and the risk of disease later in life, but more research is needed to confirm this. There is no evidence supporting the use of soy protein formulae for the prevention or management of infantile colic, regurgitation, or prolonged crying. (2)
On the other hand, experts suggested that soy formula is the most appropriate choice for full-term babies with galactosemia or hereditary lactase deficiency which are the two medical conditions that prevent babies from breaking down the natural sugars in cow’s milk. (1,2)
Phytoestrogens are found in many food products in addition to soy infant formula, especially soy-based foods such as tofu, soy milk, and in some dietary supplements.
Soy formula is also the most appropriate choice for vegan families. Although the vitamin D3 in most soy formulas is currently sourced from sheep lanolin, they’re the closest available option to fully vegan baby formula.
Summary
Some parents who prefer soy formula believe it’s the most beneficial choice for their child’s current and future health, but more research is needed to confirm this. Soy formula is the best feeding choice for vegan families and babies with specific medical conditions.
Is soy isoflavones harmful to babies ?
Soy formulas are naturally rich in isoflavones which is a plant based compound with a structure similar to that of the hormone estrogen. Estrogen is, in large part, responsible for female sexual development. (8)
Due to the high amount of isoflavones present in soy based infant formulas (SBIF) the concern regarding its adverse effects are increasing.
In the relevant animal studies, various abnormalities in animals exposed to soy isoflavones were reported. This study examined the effects of isolated compounds, mainly genistein, whereas SF used for infant nutrition contains several other components, including different aglycones. Still it’s important to note that estrogen is much more potent than soy isoflavones, and that animals metabolize soy isoflavones differently than humans.(9)
One study, of the journal of clinical endocrinology and metabolism (10) followed 410 infants fed only breast milk, cow-milk formula, or soy formula from birth to nine months. It was observed that serum estrogen levels were similar between groups, yet the uterine volume of the soy-fed infant girls was significantly altered in a way characteristic of high estrogen exposure.
As the implications of those findings are still unknown, the observed differences are not strong enough. This study serves as proof-of-principle for developmental effects of soy formulas. Studies are needed to further evaluate the effects of soy on child development.(6)
As per the experimental studies, it results that SF-fed children, particularly the youngest, can have significant clinical problems. In most of the cases, poor or no negative effect has been observed. Soy infant formula was selected for National Toxicology Program (NTP) Evaluation of Risks to Human Reproduction (NTP CERHR) concludes that, there is “minimal concern for adverse effects on development in infants who consume soy infant formula” (9)
Summary
Animal studies suggest that phytoestrogens of infants fed soy formulas are significantly higher than those of adults and may affect sexual development. Finally, there is no conclusive evidence that soy formula (SF) can significantly affect human development, reproduction and endocrine function. Only hypothyroid children can have significant problems. (9)
When to avoid soy formula?
Soy formula isn’t a good choice for all babies. They are likely not appropriate for pre-term babies born, nor those born with poor renal function or a low birth weight.
Health authorities specifically highlight that although soy formula may be used to help babies grow and develop optimally, it generally doesn’t confer any advantages over a cow’s-milk-based formula.
So, they typically recommend that healthy babies from non-vegan families and babies who do not have galactosemia or a hereditary lactase deficiency choose cow’s milk formula. (1,2)
Summary
Finally, Soy-based formulas are not a good option for preterm babies born, nor those born with poor renal function or a low birth weight. They may also not be the best choice for infants with cow’s milk allergy or intolerance.
Conclusion
Soy-based infant formulas should be used with caution. Animal studies suggest that phytoestrogens of infants fed soy formulas are significantly higher than those of adults and may affect sexual development. Actual human studies being scarce, but associations between soy formulas and altered sexual development have been found in infant girls. Due to the scarcity of human studies, several researchers have warned that the use of soy formulas should be avoided or at least minimized. Also, while soy formulas do not impair the growth of healthy, full-term infants, they can cause growth problems and rickets in premature infants. Soy formula is not an appropriate choice for babies born prematurely, nor those with low birth weights, poor renal function, or a cow’s milk allergy.(6)
References:-
- Use of soy protein-based formulas in infant feeding – PubMed (nih.gov)
- Soy-Based Infant Formula: Are Phyto-Oestrogens Still in Doubt? – PMC (nih.gov)
- Soy protein infant formulae and follow-on formulae: a commentary by the ESPGHAN Committee on Nutrition – PubMed (nih.gov)
- Frontiers | Soy-Based Infant Formula: Are Phyto-Oestrogens Still in Doubt? (frontiersin.org)
- Questions & Answers for Consumers Concerning Infant Formula | FDA
- Is soy good or bad for you? – Examine
- Is Soy Formula Safe for Your Baby? (healthline.com)
- Aluminum exposure and toxicity in neonates: a practical guide to halt aluminum overload in the prenatal and perinatal periods – PubMed (nih.gov)
- Soy-Based Infant Formula: Are Phyto-Oestrogens Still in Doubt? – PubMed (nih.gov)
- A Longitudinal Study of Estrogen-Responsive Tissues and Hormone Concentrations in Infants Fed Soy Formula – PubMed (nih.gov)
