Use of Soy Protein-Based Formulas in Infant Feeding

Abstract

Soy protein-based formulas have been available for almost 100 years. Since the first use of soy formula as a milk substitute for an infant unable to tolerate a cow milk protein-based formula, the formulation has changed to the current soy protein isolate. Despite very limited indications for its use, soy protein-based formulas in the United States may account for nearly 25% of the formula market. This report reviews the limited indications and contraindications of soy formulas. It will also review the potential harmful effects of soy protein-based formulas and the phytoestrogens contained in these formulas.T HE AMERICAN ACADEMY of Pediatrics (AAP) is committed to the use of human milk as the ideal source of nutrition for infant feeding. However, by 2 months of age, the majority of infants in North America are receiving at least some formula. Soy-based infant formulas have been available for almost 100 years. 1 Despite limited indications, soy protein-based formula accounts for approximately 20% of the formula market in the United States. Because an infant formula provides a source of nutrition for an extended interval, its nutritional adequacy must be proven, and the indications for its use must be substantiated and well understood. This statement updates the 1998 AAP review of soy protein-based formulas and addresses the ongoing concern of phytoestrogens in soy formulas. COMPOSITIONIsolated soy protein-based formulas currently on the market are all free of cow milk protein and lactose and provide 67 kcal/dL. All are iron-fortified and meet the vitamin, mineral, and electrolyte specifications addressed in the 2004 guidelines from the AAP for feeding term infants 2 and established by the US Food and Drug Administration. 3 The protein is a soy isolate supplemented with L-methionine, L-carnitine, and taurine to provide a protein content of 2.45 to 2.8 g per 100 kcal or 1.65 to 1.9 g/dL. The fat content of soy protein-based formulas is derived primarily from vegetable oils. The quantity of specific fats varies by manufacturer and is usually similar to those in the manufacturer's corresponding cow milk-based formula. The fat content ranges from 5.02 to 5.46 g per 100 kcal or 3.4 to 3.6 g/dL. The oils used include soy, palm, sunflower, olein, safflower, and coconut. Docosahexaenoic and arachidonic acids now are added routinely.In formulas, carbohydrate sources are corn maltodextrin, corn syrup solids, and sucrose, with content ranging from 10.26 to 10.95 g per 100 kcal or 6.9 to 7.4 g/dL. Until 1980, mineral absorption from soy formulas was erratic because of poor stability of the suspensions and the presence of excessive soy phytates. 4 Because soy protein isolate formulas still contain 1.5% phytates, and up to 30% of the total phosphorus is phytate bound, they contain 20% more calcium and phosphorus than cow milk-based formulas and maintain the ratio of calcium to available phosphorus of 1.1 to 2.0:1. With the current formulations, bone mineralization, serum concentrations of calcium and phosphorus, and alka...

Soy, phytoestrogens and their impact on reproductive health

“…These formulas contain a soy protein isolate, supplemented with additional amino acids, minerals, vitamins and fat necessary to support growth and development. In the US, it is estimated that 20-25% of infants are fed on soy-based formula sometime during the first year of life (Bhatia and Greer, 2008;NTP, 2010). Guidelines issued by societies such as the American Academy of Pediatrics (AAP) (Bhatia and Greer, 2008) or the European Society for Pediatric Gastroenterology Hepatology and Nutrition (ESPGHAN) Committee on Nutrition (Agostoni et al, 2006) do not recommend the exclusive use of soy formula over non-soy and/or breast milk.…”

“…In the US, it is estimated that 20-25% of infants are fed on soy-based formula sometime during the first year of life (Bhatia and Greer, 2008;NTP, 2010). Guidelines issued by societies such as the American Academy of Pediatrics (AAP) (Bhatia and Greer, 2008) or the European Society for Pediatric Gastroenterology Hepatology and Nutrition (ESPGHAN) Committee on Nutrition (Agostoni et al, 2006) do not recommend the exclusive use of soy formula over non-soy and/or breast milk. In fact, the use of these soy-based formulas is only recommended for infants that develop cow milk allergies or lactose intolerance, although either a parental conviction that soy consumption provides health benefits, or a vegetarian lifestyle might well represent the major reasons.…”

“…As we have seen, the scarcity of human data available and the apparent lack of significant long-term detrimental effects may explain why consumers, clinicians and health organizations usually consider soy formula as a safe alternative to breastfeeding (Bhatia and Greer, 2008;COT, 2003;NTP, 2006NTP, , 2010. It should be noted however that a recent safety assessment of soy infant formula by the review panel from the Center for the Evaluation of Risks to Human Reproduction (CERHR, established by the National Toxicology Program, NTP and the National Institute of Environmental Health Sciences, NIEHS) failed to issue a conclusive recommendation on the reproductive and developmental toxicity because of the limited utility of available humans studies (NTP, 2010).…”

Diagnosis and management of cow’s milk protein allergy in infants

“…In particular, infants with multiple food allergies and eosinophilic enterocolitis also react to soy protein (35). Therefore, different specialist groups have different standpoints on the use of Soy formula for CMPA, but is generally not recommended before the age of 6 months (26,34,36,37). Soy could be considered as an alternative, the possible cross reactivity in mind, in cultures where the hydrolyzation process with pork-derived enzymes is considered a problem and beyond the age of 6 months.…”

The Black Cutworm as a Potential Human Food

“…The development of novel protein sources such as Fish Protein Concentrate (FPC) [1,2] , Single Cell Protein (SCP) [3,4] and Soybean Protein (SBP) [5,6] have made significant contributions toward the alleviation of the world's protein deficiency [7] . However, there is still an estimated one billion people suffering from protein deficiency and malnutrition [8] .…”