  Small magnetic fluctuations ($B_1/B_0 \sim 10^{-4}$) are intrinsically
present in a magnetic confinement plasma due to turbulent currents. While the
perpendicular transport of particles and heat is typically dominated by
fluctuations of the electric field, the parallel stream of plasma is affected
by fluttering magnetic field lines. In particular through electrons, this
indirectly impacts the turbulence dynamics. Even in low beta conditions, we
find that $E\times B$ turbulent transport can be reduced by more than a factor
2 when magnetic flutter is included in our validated edge turbulence
simulations of L-mode ASDEX Upgrade. The primary reason for this is the
stabilization of drift-Alfv\'en-waves, which reduces the phase shifts of
density and temperature fluctuations with respect to potential fluctuations.
This stabilization can be qualitatively explained by linear analytical theory,
and appreciably reinforced by the flutter nonlinearity. As a secondary effect,
the steeper temperature gradients and thus higher $\eta_i$ increase the impact
of the ion-temperature-gradient mode on overall turbulent transport. With
increasing beta, the stabilizing effect on $E\times B$ turbulence increases,
balancing the destabilization by induction, until direct electromagnetic
perpendicular transport is triggered. We conclude that including flutter is
crucial for predictive edge turbulence simulations.
