Soybean varieties have varying amounts of isoflavones - the component that provides human medicinal benefits.

French researchers say isoflavones also are sensitive to environmental conditions, especially stress. They looked at isoflavone and protein contents of plants grown without irrigation and under simulated hail. They also compared different varieties, seeding dates and locations.

While they observed some differences in isoflavone levels due to these factors, they concluded that genetics has the biggest influence.

(Stephanie Lacombe, Thierry Aussenac, Philippe La Droitte, and Jean Dayde, France)