PHILADELPHIA, PENNYSYLVANIA. Many mothers who cannot breast feed their infants prefer to use soy- based infant formulas rather than conventional formulas based on cow's milk. A team of researchers from the universities of Iowa and Pennsylvania has just released the results of a major study of soy-based formulas and concludes that they are safe.
The study involved 563 infants who were fed cow's milk formula during infancy (starting before the age of 9
days) and 248 who were fed soy formula. The infants were enrolled during the period 1965 to 1978 and
their medical and reproductive history examined in 1999 when they were between the ages of 20 and 34
years. The researchers looked at such factors as height, weight, body mass index, pubertal maturation,
pregnancy outcomes, menstrual difficulties, sexual orientation, testicular cancer, drug usage, smoking, and
education level attained (as a measure of IQ). Most of these factors could conceivably be influenced by the
phytoestrogen content of soy formula. The researchers conclude that the exposure to soy formula in infancy
does not lead to different health or reproductive outcomes than does exposure to cow's milk formula. Thus
"the findings of the current study are reassuring about the safety of soy infant formula".