I'm not getting into any debate about scattering VS non-scattering but I do agree that certain diets will highly discourage parasites. I got this info from Paul Pitchford's excellent book Healing with Whole Foods (based on Asian traditions but including plenty of modern scientific information).
With parasites, he says it's not either/or (diet or medicine; you need both.) He describes how certain foods/ways of eating encourage proliferation of parasites and how other foods discourage them. His recommendations include both diet + ordinary anti-parasite herbs. There is a whole section devoted to parasites in the above mentioned book. Well worth looking at.