In the early episodes of Dragon Ball Z they depicted what can be considered offensive imagery and language.

Mr. PoPo the only main Black character in the show at the time was depicted with "Black face".

The creator of Dragon Ball Z had family who fought for imperial Japan (when Japan aligned with Hitler and attacked Pearl harbor)

The "strongest" characters at the time were depicted with Blonde hair and blue eyes, and is called a "Sayain"

which sound's similar to "Aryan"

The character Freiza would constantly call "the lower beings" "monkeys"

Edit: I think this particular outcry was why Toriyama changed the entire outlook of the characters in D.B.S.

The reason why they changed the Outlook of the characters in DBGT was that it was a fan made season and Toriyama had copyrights to the characters looks.

Edit: I got the idea for this article from reading an online forum where they were the people were stressing the issues about the original DBZ.

How Dragon Ball Z can be considered racist