Apple - Homebrew: Easy way to add 'gnubin' to path for multiple packages?

The proposed find based solution takes about 5 seconds to execute on my system. The following bash snippet executes in a fraction of a second.

if type brew &>/dev/null; then
  HOMEBREW_PREFIX=$(brew --prefix)
  # gnubin; gnuman
  for d in ${HOMEBREW_PREFIX}/opt/*/libexec/gnubin; do export PATH=$d:$PATH; done
  # I actually like that man grep gives the BSD grep man page
  #for d in ${HOMEBREW_PREFIX}/opt/*/libexec/gnuman; do export MANPATH=$d:$MANPATH; done
fi