Há algumas citações interessantes do texto 10 da " História da Terra Média " (Morgoth's Ring) que são diretamente abordar a questão da orc imortalidade e orc vida útil:
"They needed food and drink, and rest, though many were by training as tough as Dwarves in enduring hardship. They could be slain, and they were subject to disease; but apart from these ills they died and were not immortal, even according to the manner of the Quendi; indeed they appear to have been by nature short-lived compared with the span of Men of higher race, such as the Edain"
O Guia Completo para a Terra Média de Robert Foster observa que a expectativa de vida média da Edain é entre 70-90 anos, o que sugere que a longevidade média de Orc (exceto doença e lesão) está em algum lugar por volta dos 60 anos de idade .
Parece que o fato de certos maiar (imortais) estarem posando enquanto Orcs deu origem ao mito de que a raça orc era imortal ...
This last point was not well understood in the Elder Days. For Morgoth had many servants, the oldest and most potent of whom were immortal, belonging indeed in their beginning to the Maiar; and these evil spirits like their Master could take on visible forms. Those whose business it was to direct the Orcs often took Orkish shapes, though they were greater and more terrible. Thus it was that the histories speak of Great Orcs or Orc-captains who were not slain, and who reappeared in battle through years far longer than the span of the lives of Men.