Soy Formula for Babies

Many mothers switch to soy based formula's for infant feeding

If the mother is no longer able to breast feed her baby, many times the switch is made to either cow's milk or soy milk. Is it the right choice or are there risks involved in the choice for soy protein? Cow's milk, if processed to much, does no longer contain the right enzymes to process the milk without food allergies. Raw milk, carefully heated (never with a microwave over), might be the best choice. Soy is not the right food for babies for many reasons. There are six major reasons why not to choose soy or at least to be very careful.

1. Soy is not a complete food, lacking several very important nutrients.

2. Soy is extremely rich in isoflavones and phytoestrogens. This will raise the blood levels of estradiol with in between 13.000 and 22.000 times, compared to either breast fed or cow's milk fed babies.

3. Soy is very rich in manganese. Manganese is an important trace element, necessary for many functions in our body, like mn SOD. However, it is, like selenium, a trace element. Overdosing may lead to serious damage of the brain of the baby.

4. Soy contains phytic acid. This blocks the absorption of calcium, causing underdevelopment of bone. Sometimes soy products are offered after removal of the phytic acid. This is even worse, since soy without phytic acid improves manganese absorption several times.

5. Isolated soy proteins used in soy drinks contain up to 100 times more free radicals compared to casein. After preparing the soy proteins for commercial food preparations the amount of free radicals may raise even 19 times higher!

6. Soy formula's for babies may increase the development of breast and vaginal tissues at very young ages.

1. Soy protein infant formulae and follow-on formulae: a commentary by the ESPGHAN Committee on Nutrition.

J Pediatr Gastroenterol Nutr. 2006 Apr;42(4):352-61 .ESPGHAN Committee on Nutrition, Agostoni C, Axelsson I, Goulet O, Koletzko B, Michaelsen KF, Puntis J, Rieu D, Rigo J, Shamir R, Szajewska H, Turck D. University of Milano, Milano, Italy.

This comment by the European Society for Paediatric Gastroenterology Hepatology and Nutrition (ESPGHAN) Committee on Nutrition summarizes available information on the composition and use of soy protein formulae as substitutes for breastfeeding and cows' milk protein formulae as well as on their suitability and safety for supporting adequate growth and development in infants. Soy is a source of protein that is inferior to cows' milk, with a lower digestibility and bioavailability as well as a lower methionine content. For soy protein infant formulae, only protein isolates can be used, and minimum protein content required in the current European Union legislation is higher than that of cows' milk protein infant formulae (2.25 g/100 kcal vs. 1.8 g/100kcal). Soy protein formulae can be used for feeding term infants, but they have no nutritional advantage over cows' milk protein formulae and contain high concentrations of phytate, aluminum, and phytoestrogens (isoflavones), which might have untoward effects. There are no data to support the use of soy protein formulae in preterm infants. Indications for soy protein formulae include severe persistent lactose intolerance, galactosemia, and ethical considerations (e.g., vegan concepts). Soy protein formulae have no role in the prevention of allergic diseases and should not be used in infants with food allergy during the first 6 months of life. If soy protein formulae are considered for therapeutic use in food allergy after the age of 6 months because of their lower cost and better acceptance, tolerance to soy protein should first be established byclinical challenge. There is no evidence supporting the use of soy protein formulae for the prevention or management of infantile colic, regurgitation, or prolonged crying.

top

2a. Isoflavone content of infant formulas and the metabolic fate of these phytoestrogens in early life.

Setchell KD, Zimmer-Nechemias L, Cai J, Heubi JE. Clinical Mass Spectrometry Center, Children's Hospital Medical Center, Cincinnati, OH 45229, USA. setck0@chmcc.org Am J Clin Nutr. 1998 Dec;68(6 Suppl):1453S-1461S.

Soy-based infant formulas have been in use for >30 y. These formulas are manufactured from soy protein isolates and contain significant amounts of phytoestrogens of the isoflavone class. As determined by HPLC, the isoflavone compositions of commercially available formulas are similar qualitatively and quantitatively and are consistent with the isoflavone composition of soy protein isolates. Genistein, found predominantly in the form of glycosidic conjugates, accounts for >65% of the isoflavones in soy-based formulas. Total isoflavone concentrations of soy-based formulas prepared for infant feeding range from 32 to 47 mg/L, whereas isoflavone concentrations in human breast milk are only 5.6 +/- 4.4 microg/L (mean +/- SD, n = 9). Infants fed soy-based formulas are therefore exposed to 22-45 mg isoflavones/d (6-11 mg x kg body wt(-1) x d(-1)), whereas the intake of these phytoestrogens from human milk is negligible (<0.01 mg/d). The metabolic fate of isoflavones from soy-based infant formula is described. Plasma isoflavone concentrations reported previously for 4-mo-old infants fed soy-based formula were 654-1775 microg/L (mean: 979.7 microg/L: Lancet 1997:350;23-7), significantly higher than plasma concentrations of infants fed either cow-milk formula (mean +/- SD: 9.4 +/- 1.2 microg/L) or human breast milk (4.7 +/- 1.3 microg/L). The high steady state plasma concentration of isoflavones in infants fed soy-based formula is explained by reduced intestinal biotransformation, as evidenced by low or undetectable concentrations of equol and other metabolites, and is maintained by constant daily exposure from frequent feeding. Isoflavones circulate at concentrations that are 13,000-22,000-fold higher than plasma estradiol concentrations in early life. Exposure to these phytoestrogens early in life may have long-term health benefits for hormone-dependent diseases.

2b. Isoflavones in urine, saliva, and blood of infants: data from a pilot study on the estrogenic activity of soy formula.

J Expo Sci Environ Epidemiol. 2008 Jul 30. Cao YA, Calafat AM, Doerge DR, Umbach DM, Bernbaum JC, Twaddle NC, Ye XI, Rogan WJ. aEpidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA.

In the United States, about 25% of infant formula sold is based on soy protein, which is an important source of estrogenic isoflavones in the human food supply. Nevertheless, few studies report isoflavone levels in infants. We did a partly cross-sectional and partly longitudinal pilot study to examine children's exposure to isoflavones from different feeding methods.

A total of 166 full-term infants between birth and 1 year of age were recruited into soy formula, cow milk formula, or breast milk regimens according to their feeding histories. A total of 381 urine, 361 saliva, and 88 blood samples were collected at 382 visits. We used automated online solid-phase extraction coupled to high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) for measuring three isoflavones (daidzein, genistein, and equol) in urine, and used similar LC/MS/MS techniques for saliva and blood spots.

Concentrations of daidzein and genistein were undetectable in most blood or saliva samples from children fed breast milk or cow milk formula. The proportion of non-detectable values was somewhat lower in urine than in the other matrices. Concentrations of equol were detectable only in a few urine samples. For both daidzein and genistein, urine contained the highest median concentrations, followed by blood and then saliva. Urinary concentrations of genistein and daidzein were about 500 times higher in the soy formula-fed infants than in the cow milk formula-fed infants. The correlations between matrices for either analyte were strikingly lower than the correlation between the two analytes in any single matrix. We did not find significant correlations between isoflavone concentrations and the levels of certain hormones in children fed soy formula. Our results, based on much larger numbers of infants, strongly confirm previous reports, but whether phytoestrogens in soy formula are biologically active in infants is still an open question. We plan further longitudinal studies focusing on physical and developmental findings reflecting the effects of estrogen exposure.

Journal of Exposure Science and Environmental Epidemiology advance online publication, 30 July 2008; doi:10.1038/jes.2008.44.

top

3. Manganese content of soy or rice beverages is high in comparison to infant formulas.

J Am Coll Nutr. 2004 Apr;23(2):124-30.Cockell KA, Bonacci G, Belonje B. Nutrition Research Division, Bureau of Nutritional Sciences, Food Directorate, Health Canada, Ottawa, Ontario, Canada. kevin_cockell@hc-sc.gc.ca

OBJECTIVE: Well-meaning but inadequately informed parents may perceive plant-based beverages such as soy beverages (SB) or rice beverages (RB) as an alternative to infant formula. Manganese (Mn) is an essential mineral nutrient found at high levels in plants such as soy and rice. Excessive Mn exposure increases the risk of adverse neurological effects.

METHODS: We analysed, by atomic absorption spectrometry, the Mn content of 36 SB, 5 RB, 6 evaporated milks (EM), 14 soy-based infant formulas (SF) and 16 milk-based infant formulas (MF), obtained from commercial outlets in Ottawa, Canada.

RESULTS: SB had the highest levels of Mn (16.5 +/- 8.6 micro g/g dry wt, mean +/- s.d.), followed by RB (9.9 +/- 1.7 micro g/g dry wt). Mn levels of individual SB/RB ranged from 2 to 17 times the mean Mn content of SF (2.4 +/- 0.7 micro g/g dry wt) and 7 to 56 times that of MF (0.70 +/- 0.35 micro g/g dry wt). EM contained very little Mn (0.02 +/- 0.03 micro g/g dry wt). Calculated mean Mn intakes from SB/RB by infants up to 6 months of age, assuming complete substitution of these products (0.78 L/day), approached the Tolerable Upper Intake Level (UL) for 1-3 year olds (no UL for Mn is available for infants under 1 year of age). Expressed as micro g Mn/100 kcal, SB/RB exceeded the range derived from ULs and typical energy intakes of 1-3 year olds.

CONCLUSIONS: SB/RB should not be fed to infants because they are nutritionally inadequate and contain Mn at levels which may present an increased risk of adverse neurological effects if used as a sole source of nutrition

top

4. Manganese absorption in humans: the effect of phytic acid and ascorbic acid in soy formula.

Am J Clin Nutr. 1995 Nov;62(5):984-7.Davidsson L, Almgren A, Juillerat MA, Hurrell RF. Nestlé Research Centre, Lausanne, Switzerland.

The absorption of manganese from soy formula was studied in adult volunteers by extrinsic labeling of test meals with 54Mn, followed by whole-body retention measurements for approximately 30 d after intake. Eight subjects participated twice in each of the two studies, acting as his or her own control. Soy formula containing the native content of phytic acid was compared with a similar dephytinized formula: geometric mean manganese absorption increased 2.3-fold from 0.7% (range: 0.2-1.1%) to 1.6% (range: 1.0-7.2%) (P < 0.01) with the dephytinized formula. In addition, the effect of the ascorbic acid content of the phytic acid-containing formula was investigated. Manganese absorption was not influenced by an increase in the ascorbic acid from 625 mumol/L (110 mg/L) to 1250 mumol/L (220 mg/L): the geometric mean manganese absorption was 0.6% (range: 0.3-1.0%) and 0.6% (range: 0.3-1.1%), respectively. In conclusion, fractional manganese absorption was approximately doubled by the dephytinization of soy formula but was not influenced by an increase in the ascorbic acid content of a soy formula containing the native amount of phytic acid.

top

5. Carbon-centered radicals in isolated soy proteins.

J Food Sci. 2008 Apr;73(3):C222-6.Boatright WL, Jahan MS, Walters BM, Miller AF, Cui D, Hustedt EJ, Lei Q. Department of Animal and Food Sciences, University of Kentucky, 412 W.P. Garrigus Building, Lexington, KY 40546-0215, USA. wlboat1@uky.edu

Solid-state electron paramagnetic resonance (EPR) spectroscopy of commercial samples of isolated soy proteins (ISP) revealed a symmetrical free-radical signal typical of carbon-centered radicals (g= 2.005) ranging from 2.96 x 10(14) to 6.42 x 10(14) spins/g. The level of free radicals in ISP was 14 times greater than similar radicals in sodium caseinate, 29 times greater than egg albumin, and about 100 times greater levels than casein. Nine soy protein powdered drink mixes contained similar types of free radicals up to 4.10 x 10(15) spins/g of drink mix, or up to 6.4 times greater than the highest free-radical content found in commercial ISP. ISP samples prepared in the laboratory contained trapped radicals similar to the levels in commercial ISP samples. When ISP was hydrated in 2.3 mM sodium erythorbate or 8.3 mM L-cysteine, frozen and dried, the level of trapped free radicals increased by about 17- and 19-fold, respectively. The ESR spectrum of defatted soybean flakes contained overlapping signals from the primary free-radical peak (g= 2.005) and a sextet pattern typical of manganese-II. The manganese signal was reduced in the laboratory ISP and very weak in the commercial ISP.

top

6. Pilot studies of estrogen-related physical findings in infants.

Environ Health Perspect. 2008 Mar;116(3):416-20.Bernbaum JC, Umbach DM, Ragan NB, Ballard JL, Archer JI, Schmidt-Davis H, Rogan WJ. Department of Pediatrics, Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, Pennsylvania, USA.

BACKGROUND: Soy formula containing estrogenic isoflavones is widely used in the United States. Infants consuming soy formula exclusively have high isoflavone exposures. We wanted to study whether soy formula prolonged the physiologic estrogenization of newborns, but available quantitative descriptions of the natural history of breast and genital development are inadequate for study design.

OBJECTIVE: We piloted techniques for assessing infants' responses to the withdrawal from maternal estrogen and gathered data on breast and genital development in infants at different ages.

METHODS: We studied 37 boys and 35 girls, from term pregnancies with normal birth weights, who were < 48 hr to 6 months of age, and residents of Philadelphia, Pennsylvania, during 2004-2005. One-third of the children of each sex and age interval were exclusively fed breast milk, soy formula, or cow-milk formula. Our cross-sectional study measured breast adipose tissue, breast buds, and testicular volume; observed breast and genital development; and collected vaginal wall cells and information on vaginal discharge. We assessed reliability of the measures.

RESULTS: Breast tissue was maximal at birth and disappeared in older children, consistent with waning maternal estrogen. Genital development did not change by age. Breast-milk secretion and withdrawal bleeding were unusual. Vaginal wall cells showed maximal estrogen effect at birth and then reverted; girls on soy appeared to show reestrogenization at 6 months.

CONCLUSIONS: Examination of infants for plausible effects of estrogens is valid and repeatable. Measurement of breast tissue and characterization of vaginal wall cells could be used to evaluate exposures with estrogen-like effects.

top