Simplify the following text for a Grade 6 native English-speaking person.
Original: Bagels have become a popular bread product in the United States , Canada and the United Kingdom , especially in cities with large Jewish populations , many with different ways of making bagels . Like other bakery products , bagels are available ( either fresh or frozen , and often in many flavor varieties ) in many major supermarkets in those countries .
Simplified: Frozen bagels were first introduced in 1960 .