DES MOINES, Iowa (AP) — Iowa State University researchers are moving ahead with a long-delayed project in which a dozen students will be paid to eat genetically modified bananas. The Des Moines Register reports that the bananas were created by an Australian scientist and have a gene that’s supposed to help people living in Africa make vitamin A. The participants would be paid $900 each.

The trial has been criticized because natural-food proponents say genetically modified foods can be dangerous. The experiment’s proponents say the gene came from a different type of banana and is safe to eat.

Earlier this week, activists delivered petitions calling on the project’s halt to university officials and the Bill and Melinda Gates Foundation, which is funding the project. The activists said more than 57,000 people signed the petition.