Complex sentence: Opponents of the commercials have also noted that saying HFCS is made from corn is misleading, as ethanol and certain plastics are also made out of corn, therefore just because something is made out of corn it should not be assumed that it is safe to eat.
Split into simpler sentences: Opponents of the commercials have also noted that saying HFCS is made from corn is misleading, as ethanol and certain plastics are also made out of corn. Therefore it is argues that just because something is made out of corn it should not be assumed that it is safe to eat.