While there is growing acceptance in the medical community that breast milk best provides infants with their nutritional needs, there is also a contingent of evidence that alternatives like soy formula are not only nutritionally inferior, but harmful as well.
Soy-based infant formulas are marked both by a lack of critical nutrients like certain essential fatty acids, lactoferrin, immune factors, and DHA brain growth factor, all key components of breast milk, and by the presence of toxins like phytates, nitrites, and topoisomerase II inhibitors, as well as estrogenic substances like daidzen and genistein.
One of their most harmful components, however, may be manganese, a metal proven to be toxic if taken in large amounts. While trace amounts of manganese are found in all breast milk, soy-based formulas typically contain more than 100 times the amount found in normal breast milk, to as much as 200 times the amount in breast milk.
The reason this is so damaging is that infant metabolic systems are too undeveloped to process disproportionate and unnatural amounts of minerals, especially ones that can be toxic in high amounts like manganese.
According to Dr. Francis Crinella, clinical professor of pediatrics at UC-Irvine, for the typical 8-month-old soy-fed infant, “a significant amount [of manganese], about 8 percent, is deposited in a brain region vulnerable to threat of manganese attack.”
Both human studies and animal studies have shown a strong connection between high levels of dietary manganese and neurological disorders. One of these human studies was inadvertent. In 1995, 57 babies were intravenously fed nutrient formulas with amounts of manganese comparable to soy-based infant formulas. Within a few months, two of the babies developed movement disorders and six had notable damage to their basal ganglia, a group of nuclei in the brain associated with motor control, procedural learning, and emotions.
Crinella’s own studies on children found that children with hyperactivity issues had higher levels of manganese in their scalp hair than children without such behavioral issues. Based on the dietary history of his subjects, he concluded that the only source of manganese that could have caused such a disparity in the amounts in their bodies would have been from the soy-based formulas the hyperactive children were fed as infants.
Indeed, he clarified, “the brain undergoes a tremendous proliferation of neutrons, dentrites and synapses during the first months of life. The brain especially is vulnerable in early life precisely because such rampant growth is taking place, and at that time intrusions by potentially toxic substances like manganese perturbing the emerging neural organization can exert long-term effects. Manganese ingested during a period of rapid brain growth and deposited in the critical basal ganglia region may affect behavior during puberty when powerful stresses are un-leashed in the dopamine neurons, and altered behavioral patterns appear.”
His study on rats and manganese adds further light on the issue. Rats given an amount of manganese even with that in breast milk for just 18 days performed no differently than rats given no manganese. Rats given manganese just five times more than that in breast milk had reductions in their basal ganglia dopamine of 48%, and rats given an amount 10 times had average reductions of 63%. For perspective, the average soy formula contains more than 100 times the amount of manganese than that in human milk.
Sadly, there is little movement to bring forth changes in awareness to the dangers of soy formulas, as the National Institute of Health voted as recently as 2009 that the health risks in soy-based formulas was “minimal,” due to corporate pressure from the soy industry. The voting panel also voted to turn down a motion to require warning labels on soy formulas, and another to require soy formula to be taken by prescription only with close doctor supervision.
Due to the misalignment between consumer and industry interests, it is important to be aware of the risks associated with the products you choose to feed your infant, as there is little ethical oversight covering the childcare industry.
Sources:
http://articles.mercola.com/sites/articles/archive/2001/06/13/soy-formula-part-one.aspx
http://www.westonaprice.org/soy-alert/soy-formula-panel-caves-to-industry-pressure
http://www.precisionnutrition.com/all-about-phytates-phytic-acid
http://en.wikipedia.org/wiki/Basal_ganglia
http://www.ars.usda.gov/is/ar/archive/jan04/soy0104.htm
