During the East Africa famine of 1980-81, the US sent yellow corn meal to Kenya. Kenyans are used to white corn meal, "ugali", used to make the staple food dish, "posho". Why, they asked, was this relief maize meal yellow in color?
Rumors soon were flying saying that the yellow color was due to contraceptives being added to the maize meal. After all, aren't the Western nations always telling us to reduce our birthrate?
As a result, none of our workers would eat the yellow meal. We tried telling them that we had been eating yellow cornbread all our lives, and had four children! The "contraceptives" just didn't work! :-)
I also heard that they refused to eat food from the US because the corn, etc. was "genetically modified."