No one is monitoring, like trans fats, which have caused millions of premature deaths; refer below.

It is claimed that Americans have eaten GM foods for years with no ill effects. But these foods are unlabeled in the US and no one has monitored the consequences. With other novel foods like trans fats, it has taken decades to realize that they have caused millions of premature deaths.[1]

1. Paula Hartman Cohen, 2006. Trans Fats: The story behind the label. Harvard Public Health Review. hsph.harvard.edu