In the comic strip Thimble Theater where Popeye debuted, Segar originally didn't give any explanation for why Popeye was so tough. Later, as he kept getting queries about the Sailorman's strength, he had Popeye explain it by saying that he had eaten spinach every day from the time he was a lad. (At the time, articles were appearing touting the benefits of eating spinach.) So, in the "canonical" Popeye sources, he never ate anything else to get strong. However, in the Famous Studios' cartoon, Greek Mirthology, Popeye tells his nephews the story of his great, great, great, great grandfather Hercules. In a flashback, Hercules was seen sniffing garlic and gaining super strength. By the end of the cartoon, though, he had discovered spinach and switched over to it. Whether the story was "real" or whether Popeye was just trying to get his nephews to eat the green veggie is open to debate.