Popeye the Sailor Man（《大力水手》） first became a popular cartoon in the 1930s.The sailor in that cartoon ate lots of spinach（菠菜） to make him strong.People watched him，and they began to buy and eat a lot more spinach.Popeye helped sell 33% more spinach than before!Spinach became a necessary part of many people's diets. Even some children who hated the taste began to eat the vegetable.
Many people thought that the iron in spinach made Popeye strong，but this is not true.Spinach does not have any more iron than other green vegetables.
People thought spinach had a lot of iron because the people who studied the food made a mistake.In the 1890s，many people studied what was inside vegetables.This group said that spinach had ten times more iron than it did.The group wrote the number wrong，but everyone accepted it.
Today，we know that the little iron in spinach cannot make a difference in how strong a person is.However，spinach does have something else that the body needs folic acid（叶酸）.
It is interesting to point out that folic acid can help make a person strong.Maybe it was really the folic acid that made Popeye strong.
