The new research claims that a mother's consumption of a particular soy nutrient elicits changes in an embryo's gene behavior that can later reduce the risk of obesity.
Scientists at Duke University Medical Center have revealed that mice fed diets rich in the soy component genistein gave birth to pups that remained slimmer as adults. According to the scientists, control group mice that did not receive prenatal genistein were double the weight of their genistein-fed counterparts.
"We are increasingly finding that our parent's and even our grandparent's nutritional status and environmental exposures can regulate our future risk of disease," said Dr Randy Jirtle, senior author of the study.
"In other words, it may not only be the hamburgers and fries we are eating, but also what our parents consumed or encountered in the environment that predisposes us to various conditions," he added.
Published in the April 1 issue of the journal Environmental Health Parspectives, the findings could explain why Asians, who consume large amounts of soy, have lower rates of obesity, said the researchers.
But genistein is currently viewed with some suspicion after a number of studies have linked it to certain negative health impacts in animal tests.
These include the disruption of ovary development and damage to human sperm, as well as inhibiting full sexual development and intestinal cell growth.
But in other studies, genistein has been shown to have potential health benefits, including prevention activity against hormone-responsive tumors, such as breast, ovarian and prostate cancer.
The results of the current study claim to be another link in the chain of evidence that an individual's long-term health is influenced by prenatal factors, including diet.
According to Jirtle, certain environmental factors before birth can alter the way a specific gene behaves, without changing the genetic sequence in any way.
The Duke researchers found that genistein acted on a particular gene in mice, called the agouti gene. And although this does not act in the same ways in humans, the scientists claim that "soy's potential benefits could exert themselves" through other human genes.
"Our study demonstrates there are highly sensitive windows early in development when environmental exposures can permanently alter the offspring's adult susceptibility to disease," said Jirtle.
"Therefore, we need to examine the effect of environmental exposures during pregnancy, not just in adulthood, if we want to accurately assess their risk or benefit to humans."
And according to the scientists, genistein may not be the only compound that can reduce the risk of obesity. Previous research by Jirtle showed that folic acid and vitamin B12 had the same affect when fed to pregnant mice.
However, Jirtle pointed out that it is still unclear as to how different nutrients interact in combination or in extremely high doses, suggesting the need for further research before the health benefits can be confirmed.