This did not initially exist in Segar's comic Thimble Theatre, where Popeye originated, later simply becoming the food that Popeye favored in order to remain strong, before seeing more widespread use in post-Segar comics. Since the earliest animated cartoons, however, as produced by Fleischer Studios, it was introduced in its strength-boosting capacity and in this form would remain a staple of all of Popeye's screen incarnations.
The hero's empowerment
The animated cartoons more notedly adhere to a format in which spinach is Popeye's main means for overcoming the greatest of obstacles. Even if the cartoon acknowledges Popeye's immense strength to begin with (later ones from the Famous era make him much weaker before spinach), consumption of the vegetable augments Popeye's physical might to the extreme, allowing the viewer to enjoy a power fantasy and enabling the sailor to even break the laws of physics at times.
The villain's comeuppance
In Popeye's dealings with opponents such as Bluto, spinach is consumed when the sailor's well-being is threatened or Olive Oyl is on the verge of being abused. After eating the vegetable, Popeye strikes at the antagonist with his increased strength, wherein the blows can immediately render the erstwhile competitor unconscious, send him airborne to a distant destination, initiate the use of various props which serve to immobilize and otherwise humble him, etc. Often, this comeuppance comes in the form of a humorous reprieve to what had been a tense and life-threatening situation and serves as a concluding "punchline" for the cartoon episode.
Spinach as eaten by others
Popeye is not the only character in the franchise to eat spinach; other characters have consumed it as well. For cases involving female antagonists such as the Sea Hag, since Popeye cannot clobber women, it is Olive Oyl who ingests the vegetable in order to defeat the villainess. In the theatrical shorts Hospitaliky, its color remake For Better or Nurse and Beaus Will Be Beaus, Popeye force-feeds Bluto spinach. At least in the animated cartoons, everybody would gain a surge of power comparable to Popeye's. Interestingly enough, while being so powerful, it is commercially available in Popeye's stories. Literally anyone can buy a can of spinach at the nearby grocery, but Popeye seems the only consumer. Brutus once managed to monopolize the spinach market to depower Popeye, but the villain himself did not consume it.
- Spinach increases the strength and speed of a character.
- It makes Popeye invulnerable, giving him a skin as resilient as steel.
- It can turn Popeye into a rocket, transform his clothes or otherwise change his appearance.
- It has been used to transform a biplane into a F-18 Hornet and perform other such changes.
- Once, Popeye summoned a knight's armor and horse with spinach. (Ancient Fistory)
- Rubbing the can of spinach, Popeye could do deeds to rival Aladdin's lamp (Aladdin and His Wonderful Lamp).
- Spinach was used to negate the effects of a fast-aging ray when Popeye was abducted by aliens (Popeye, the Ace of Space).
- Ye King's Spinach, a variety that Popeye found in a haunted ship, could turn him invisible (Spooky Swabs).
- Popeye gathered the necessary materials and built a full, armored house in a few seconds after eating spinach (Insect to Injury).
- Spinach can increase the strength of a common gopher to knock down a bull (Gopher Spinach).
- It could turn an innoffensive pig into a furious boar ("Bad Company").
- Empowered by spinach, Popeye was able to tow a whole fleet of ships ("Popeye Snags the Sea Hag").
- The vegetable could fix a broken sword and give mastery over fencing (Parlez Vous Woo).
- Poopdeck Pappy, after eating spinach, was able to have a massive fight against the Goons, so powerful that he even tore the cartoon's film reel (Goonland).
- Spinach can boost the intelligence, artistical abilities, etcetera.
Spinach is widely associated to Popeye by the public. Due to his promoting the vegetable, the sailor hero has received honors from the spinach industry, such as the statue erected in Crystal City, Texas (the "Spinach Capitol [sic] of the World", as described on its Popeye-featuring welcome sign) in 1937.
Popeye-brand spinach (pictured right) continues to be sold by the Allen Canning Company.