The soy isoflavone genistin - at concentrations present in soy infant formula - may reduce a baby's susceptibility to rotavirus infections by as much as 74 percent, according to a University of Illinois study published in September's Journal of Nutrition.
“Rotavirus is the primary cause of diarrhea in infants, affecting virtually all children before age five. In the United States, it mainly leads to dehydration, doctor's visits, and parents missing work to care for sick children. In developing countries, though, rotavirus causes approximately 611,000 deaths each year,” said Sharon Donovan, the Melissa M. Noel Professor of Nutrition at the U of I.
Although rotavirus vaccines have recently become available, they are expensive and cannot be given to some infants, she said.
“It's exciting to think that the isoflavones in soy formula could be a cost-effective nutritional approach to decreasing the incidence and severity of rotavirus infections, especially among children in developing countries who are most at risk,” said the scientist of her work with doctoral candidate Aline Andres, who conducted the experiments.
In the study, cells in culture were exposed to rotavirus in the absence or presence of soy isoflavones, biologically active compounds in soy that are thought to have health benefits. Soy contains a number of different forms of isoflavones, and all were tested individually and as the complete mixture present in infant formula.
“Genistin and the mixture significantly reduced rotavirus infectivity by 33 to 74 percent,” she said. “But when genistin was taken out of the mixture, anti-rotavirus activity was lost, suggesting that it is the active component in reducing infectivity.”