Spinach is thought to have originated in ancient Persia (modern Iran and neighboring countries) and arrived in Europe around the year 1000. In 1920 the myth of Popeye, erroneously led to believe that spinach was the vegetable with the highest iron content. To tell the truth the iron contained in them it is not easily assimilated by the human body. It contains 23 calories per 100 grams since they contain water to 90%. In a 100 g (3.5 oz) serving providing only 23 calories. In addition spinach helps the immune system and protect the eyesight.