Dúnedain Survival Rations

[Ardamir the Blessed]

Aragorn's healing ability is due to the fact that he is descended from Lúthien (one of the 'children of Lúthien), like Elrond, not that he is a Númenórean.

Letter #155:

Anyway, a difference in the use of 'magic' in this story is that it is not to be come by by 'lore' or spells; but is in an inherent power not possessed or attainable by Men as such. Aragorn's 'healing' might be regarded as 'magical', or at least a blend of magic with pharmacy and 'hypnotic' processes. But it is (in theory) reported by hobbits who have very little notions of philosophy and science; while A.[ragorn] is not a pure 'Man', but at long remove one of the 'children of Luthien'.

LR, 'The Houses of Healing':

‘Here I must put forth all such power and skill as is given to me,’ he [Aragorn] said. ‘Would that Elrond were here, for he is the eldest of all our race, and has the greater power.’