Doing a quick Google search did not turn up any medical literature on whether the meat of animals fed nuts (acorns in case of Iberico hogs) and peanuts (Smithfield) could induce an allergic reaction in individuals allergic to the feed nuts. Personally, I would think that the nut proteins would be broken down in digestion and not become part of the muscle and fat tissue that's made into hams.
The reason I ask is that I'm considering going to Jaleo for dinner with the kiddo before seeing King Lear. What's interesting on their allergen menu is that they do not list the Iberico ham as having nuts be do disclose that it is from acorn-fed hogs, and that only one of their cheeses is nut free. None of the cheese descriptions gives any idea as to why they'd have nuts (one lists it as being aged in apple must--sounds yummy).
Would you eat Iberico or Smithfield ham?