Soy isoflavones do not disrupt infant development, suggest scientists
formulas, a new study finds soy isoflavones do not act like female
hormones in infants, suggests new research from the government's
leading research agency.
Taking their lead from reports that soy isoflavones in soy formula might disrupt or impair development in infants - because it is believed they may act similarly to the female hormone estrogen - researchers at the Arkansas Children's Nutrition Center (ACNC) embarked on a six-year study to investigate the effects of soy-based infant formula compared with formulas made from human breast milk or cow's milk.
In rat studies, Thomas Badger, ACNC director, and part of the governments , and his team found that the animals grew and developed normally except for very minor differences that have not been found in humans. There were no adverse effects, but many healthful ones, report the scientists.
They also found that diets containing soy proteins boost the activity of certain enzymes that help remove harmful, possible cancer-promoting, toxins from the body.
However, the ACNC studies did show that soy consumption changed certain enzymes in the liver, gut and other organs that break down many medications taken by people and animals which could affect how the drugs are used by the body.
In order to find out more the researchers are currently conducting a study to compare infants who are fed soy formula with those who are breast fed or who receive cow's milk formula.
Previous studies at the center have found no apparent long-term positive or negative effects of feeding infants soy versus cow's milk formula.
A 2000 Surgeon General's report found that 64 per cent of American women breast-feed during their infants' first weeks of life. But after 6 months, that figure drops to 29 per cent. According to ARS, soy infant formulas are now consumed by 20-25 per cent of formula-fed infants in America.
Badger's research is part of Human Nutrition.