Soy Isoflavones Might Replace Rotavirus Vaccines in Infants

Monday, January 14, 2008 by: David Gutierrez, staff writer
Tags: genistin, isoflavones, soy isoflavones

(NewsTarget) A plant compound found in soy infant formulas may drastically reduce a baby's susceptibility to a potentially fatal diarrhea-causing virus, according to a new study conducted by researchers at the University of Illinois at Urbana-Champaign and published in the Journal of Nutrition.

A variety of soy isoflavones were tested on laboratory cultures of rotavirus, along with a complete mixture like that used in infant formula. A particular isoflavone called genistin was found to inhibit the virus by as much as 74 percent.

"Genistin and the mixture significantly reduced rotavirus infectivity by 33 to 74 percent," said researcher Sharon Donovan. "But when genistin was taken out of the mixture, anti-rotavirus activity was lost, suggesting that it is the active component in reducing infectivity."

Rotavirus causes diarrhea in infants, which can often be fatal in Third World countries or other areas with limited access to health care. The World Health Organization estimates that rotavirus infection led to 527,000 childhood deaths in 2004, or five percent of child deaths worldwide.

"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," Donavan said.

Isoflavones are biologically active plant compounds. Soy isoflavones have previously been linked to easing the symptoms of menopause, reducing cholesterol and improving bone density. The FDA has said that, in combination with a diet low in saturated fat and cholesterol, soy protein may help reduce the risk of heart disease.

The researchers found that the inhibitory effect of the isoflavones quickly leveled off with increasing concentration, suggesting that there may be a maximum ingestion level, beyond which the isoflavones provide no health benefit.

Because the test was carried out on cell cultures, it is still unknown how the chemicals would interact in the human body, and whether any virus-suppressing effect would still occur.

Consumer health advocate Mike Adams was quick to point out that some sources of genistin are better than others. "I do not recommend genetically modified soy products or any type of isolated soy protein, which is the cheapest and most common source of protein in high-protein food bars," Adams said. "Instead, I only recommend fermented soy products such as natto, tofu and traditionally-made soy milk, not the popular processed soy milks available in grocery stores today."

The study was funded by the U.S. Department of Agriculture and the Illinois Soybean Association.