The non-minimal coupling of scalar fields to gravity has been claimed to violate energy conditions,
leading to exotic phenomena such as traversable wormholes, even in classical theories. In this work
we adopt the view that the non-minimal coupling can be viewed as part of an effective field
theory (EFT) in which the field value is controlled by the theory’s cutoff. Under this assumption,
the average null energy condition, whose violation is necessary to allow traversable wormholes, is
obeyed both classically and in the context of quantum field theory. In addition, we establish a type
of “smeared” null energy condition in the non-minimally coupled theory, showing that the null
energy averaged over a region of spacetime obeys a state dependent bound, in that it depends on
the allowed field range. We finally motivate our EFT assumption by considering when the gravity
plus matter path integral remains semi-classically controlled.