A recent feature article in Time Magazine reported on the disturbing increase in early puberty among girls in the US. According to a recent study reported in the journal Pediatrics,1 one percent of all American girls now show signs of puberty, such as breast development or pubic hair, before the age of three; by age eight, 14.7 percent of white girls and almost 50 percent of African-American girls had one or both of these characteristics.
The consequences of truncated childhood are tragic. Young girls with mature bodies must cope with feelings and urges that most children are not well-equipped to handle. And early maturation in girls is frequently a harbinger for problems with the reproductive system later in life including failure to menstruate, infertility, breast cancer, headaches and early menopause.
In their discussion of the possible causes, Time’s reporters speculate on the role of environmental estrogens such as PCBs and DDE (a breakdown product of DDT), which have been shown to cause similar effects in animals.2 Meat and milk are also fingered as possible sources of dietary hormones.
But the authors never reveal the number-one suspect–soy infant formula. Although they mention the 1986 Puerto Rico Premature Thelarche study,3 they do not tell their readers that most significant dietary association with premature sexual development was not chicken–as reported in the press–but soy infant formula. The second most powerful association was indeed chicken–chicken raised on soy-based feed.
Approximately 25 percent of bottle-fed children in the US receive soy-based formula–a much higher percentage than in other parts of the Western world. The Woman, Infants and Children (WIC) program, which supplies free infant formula to welfare mothers, stresses soy formula for African Americans because they are supposedly allergic to milk. This would explain the astronomically high rates of premature development in African American girls.
In 1998, investigators reported that the daily exposure of infants to isoflavones in soy infant formula is six to 11 times higher on a body weight basis than the dose that has hormonal effects in adults consuming soy foods. Circulating concentrations of isoflavones in infants fed soy-based formula were 13,000 to 22,000 times higher than plasma estradiol concentrations in infants on cows milk formula.4
New Zealand toxicologist Mike Fitzpatrick estimates that an infant exclusively fed soy formula receives the estrogenic equivalent (based on body weight) of at least five birth control pills per day.5 By contrast, almost no phytoestrogens have been detected in dairy-based infant formula or in human milk, even when the mother consumes soy products.
Anecdotal reports of other problems associated with children of both sexes who were fed soy-based formula include extreme emotional behavior, asthma, immune system problems, pituitary insufficiency, thyroid disorders and irritable bowel syndrome.6
In 1998, in response to growing concerns about the damage caused by soy-based infant formula, Nutrition Reviews published an article by K. O. Klein of duPont Hospital for Children as proof that soy infant formulas do no harm.7 Yet in the article Klein notes that effects of isoflavones on various animal species include hormonal changes, increased uterine weight and infertility. “It is clear from the literature,” says Klein, “that different species and different tissues are affected by isoflavones in markedly different ways. It is difficult to know which tissues, if any, are affected in infants, and the variation among species makes extrapolation to infants inappropriate.” This is scientific double talk. Scientists may be reluctant to extrapolate but parents would certainly err on the side of caution if they knew that “isoflavones affect different tissues in markedly different ways.”
Klein says that medical literature provides “no evidence of endocrine effects. . and no changes in timing of puberty.” But she makes no mention of the Puerto Rican study which strongly implicated soy formula. Why would Dr. Klein leave out any reference to the Puerto Rican study in her review? Is it because DuPont, owner of Protein Technologies International, is the leading manufacturer of soy protein isolate?
Or is it because her review was sponsored by the Infant Formula Council? Or because Nutrition Reviews, which published her whitewash, is funded by industry giants, including Pillsbury, Hershey Foods, Kellogg, Roche, General Mills, Kraft, Campbell Soup, Monsanto, Coca-Cola, Cargill, Heinz, Nabisco, Proctor and Gamble and Pepsi-Cola?
An interesting finding of the Puerto Rican study was that consumption of milk was negatively correlated with early maturation, which means that it might be protective. Whole unprocessed milk may go a long way to mitigating some of the adverse effects of soy formula. We also know of one case in which early onset of puberty was reversed by treatment with low-potency desiccated thryoid.8
- Marcia E Herman-Giddens, et al “Secondary Sexual Characteristics and Menses in Young Girls Seen in Office Practice: A Study from the Pediatric Research in Office Settings Network,” Pediatrics, April 1997, Vol 99, No 4, Pages 505-512
- Rachel’s Environment & Health Weekly, #263, The Wingspread Statement, Part 1, December 11, 1991; Theo Colborn, Dianne Dumanoski and John Peterson Myers, Our Stolen Future, Little Brown and Company, London, 1996.
- L W Freni-Titulaer, “Premature Thelarche in Puerto Rico, A search for environmental factors,” American Journal of Diseases of Children, December 1986, Vol 140, No 12, Pages 1263-1267
- K D Setchell et al, “Isoflavone content of infant formulas and the metabolic fate of these early phytoestrogens in early life,” American Journal of Clinical Nutrition, December 1998, Supplement Pages 1453S-1461S
- C Irvine, et al, “The Potential Adverse Effects of Soybean Phytoestrogens in Infant Feeding,” New Zealand Medical Journal, May 24, 1995, Page 318.
- K O Klein, “Isoflavones, Soy-based Infant Formulas and Relevance to Endocrine Function,” Nutrition Reviews, July 1998, Vol 56, No 7, Pages 193-204.
- Personal communication, Richard James. See www.soyonlineservice.co.nz.
- Stephen Langer, Solved: The Riddle of Illness, 1994, Keats Publishing, New Canaan, CT, Page 52.
This article appeared in Wise Traditions in Food, Farming and the Healing Arts, the quarterly magazine of the Weston A. Price Foundation, Winter 2000.