Soy formula is a substitute for human

breast milk Breast milk (sometimes spelled as breastmilk) or mother's milk is milk produced by mammary glands located in the breast of a human female. Breast milk is the primary source of nutrition for newborns, containing fat, protein, carbohydrates ( lacto ...

. It is a commercial product based on the proteins found in soybeans. Soy

infant formula Infant formula, baby formula, or simply formula (American English); or baby milk, infant milk or first milk (British English), is a manufactured food designed and marketed for feeding to babies and infants under 12 months of age, usually prepar ...

uses processed soybeans as its source of protein, and comes in powdered or liquid form. Usually lactose-free, soy infant formula contains a different sugar. Infants who are intolerant of cows’ milk protein may also be intolerant of soy protein. It differs from human breast milk in a number of ways. Soy protein inhibits the absorption of iron. The soy-based formulas discussed by the

World Health Organization The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level of h ...

reports that soy formula is fortified with iron to compensate for this effect. One naturally occurring plant-based compound found in soy-based infant formula is

phytic acid Phytic acid is a six-fold dihydrogenphosphate ester of inositol (specifically, of the ''myo'' isomer), also called inositol hexakisphosphate (IP6) or inositol polyphosphate. At physiological pH, the phosphates are partially ionized, resulting ...

. It is also a strong inhibitor of iron absorption, though it can be removed in processing. It is not known how many manufacturers of soy-based formula incorporate this practice. China and Vietnam have regulated soy-based infant formulas to include NaFeEDTA (sodium-feric

ethylenediaminetetraacetic acid Ethylenediaminetetraacetic acid (EDTA) is an aminopolycarboxylic acid with the formula H2N(CH2CO2H)2sub>2. This white, water-soluble solid is widely used to bind to iron (Fe2+/Fe3+) and calcium ions (Ca2+), forming water-soluble complexes eve ...

) to fortify the formula and enhance the absorption of iron by the infant. When iron compounds are added to soy-based infant formula, the iron compound is encapsulated to prevent it from making the formula dark.

Constituents

Genetically modified ingredients may be present in soy-based infant formula. It may also be of lower nutritional value. Soy-based infant formula can have

aluminum Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It has ...

, phytates, and

phytoestrogens A phytoestrogen is a plant-derived xenoestrogen (see estrogen) not generated within the endocrine system, but consumed by eating plants or manufactured foods. Also called a "dietary estrogen", it is a diverse group of naturally occurring nonstero ...

(isoflavones) that might cause unanticipated effects. Other constituents are

amino acids Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha am ...

: such as

taurine Taurine (), or 2-aminoethanesulfonic acid, is an organic compound that is widely distributed in animal tissues. It is a major constituent of bile and can be found in the large intestine, and accounts for up to 0.1% of total human body weight. It ...

methionine Methionine (symbol Met or M) () is an essential amino acid in humans. As the precursor of other amino acids such as cysteine and taurine, versatile compounds such as SAM-e, and the important antioxidant glutathione, methionine plays a critical ro ...

, and

carnitine Carnitine is a quaternary ammonium compound involved in metabolism in most mammals, plants, and some bacteria. In support of energy metabolism, carnitine transports long-chain fatty acids into mitochondria to be oxidized for energy production, an ...

. Added minerals are phosphore, calcium, iron, and

zinc Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodi ...

. SIF also contains soy-isolate that supplies 95% of protein.

Indications

Breastfeeding is still the best option for feeding infants. There are instances when breastfeeding is not possible and the use of formula is appropriate. Indications for the use of soy-based infant formula are galactosaemia and

lactase deficiency Lactose intolerance is a common condition caused by a decreased ability to digest lactose, a sugar found in dairy products. Those affected vary in the amount of lactose they can tolerate before symptoms develop. Symptoms may include abdominal pai ...

. When a child develops an allergy to cows' milk, soy-based formula is used. SBF is less costly than other breast milk formula substitutes.

History

Past reports of the effects of soy formula have suggested that a constituent of soy formula may affect reproductive functions. However, studies have shown that no correlation exists between the consumption of soy formula and abnormality in reproductive anatomy or function. Soy-based infant formula has been used for over the past 100 years. By late 1800s and the early 1900s, supplementation of breastfeeding with formula was acceptable. Soy-based formula was used as early as 1909.

Allergies and other concerns

Soy-based infant formula is associated with allergies in infants. Chronic food protein-induced

enterocolitis Enterocolitis is an inflammation of the digestive tract, involving enteritis of the small intestine and colitis of the colon. It may be caused by various infections, with bacteria, viruses, fungi, parasites, or other causes. Common clinical manif ...

syndrome (FPIES) has been observed in infants aged younger than three months who were fed with soy formula.

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

has taken soy-based infant formula off the market. Soy-base formula accounts for about 20% of the infant formula purchased in the US. In

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

formula use is around 10%, and in

Belgium Belgium, ; french: Belgique ; german: Belgien officially the Kingdom of Belgium, is a country in Northwestern Europe. The country is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeast, France to th ...

and the UK and about 5%.

References

External links