The image of Idun's golden apples is so familiar that it is easy to overlook a genuine scholarly question underneath it: whether the fruit Snorri Sturluson describes in the thirteenth century, writing after Christian contact had reshaped much of the literary presentation of the old mythology, accurately reflects what an earlier, pre-Christian Norse audience would have imagined her keeping. Cultivated apple trees were not a well established part of Scandinavian agriculture during the Viking Age in the way they became in the medieval period that followed, and some scholars of Norse religion have suggested that Snorri's specific identification of the fruit as apples may reflect the increasingly apple-associated symbolism of later medieval Christian and continental European culture, rather than preserving a precise or unchanged detail from earlier Norse tradition. It is worth noting that in the telling of Idun's abduction itself, Loki carries her home not as an apple but transformed into a nut clutched in a falcon's talons, a detail some readers have taken as a small textual trace of a fruit tradition not originally centered on the apple, though this remains an inference rather than settled fact.
The underlying mythic idea, a keeper who alone controls fruit that grants the gods their continued youth, is paralleled in other Indo-European mythologies, most famously the golden apples of the Hesperides in Greek myth, a resemblance long noted by comparative mythologists though the precise relationship, if any, between the two traditions is not established. Whatever the fruit's exact original identity, Idun's core function, sole keeper of what keeps the gods themselves from aging, is not in doubt across every version of the story that survives.