US scientists have denounced a 2008 nutrition research project that allegedly fed genetically modified rice to a group of Chinese primary school students.

The study involving 68 Chinese children aged 6 to 8 has generated public anxiety about potential harm to the children and controversy over ethics and rules.

The study's lead author Tang Guangwen of Tufts University in Boston, Massachusetts, published a report on Aug 1 in the American Journal of Clinical Nutrition showing that 100 to 150 grams of so-called golden rice could provide 60 percent of the daily intake of vitamin A.