While your family members may deliver convincing arguments and entertaining (sic) anecdotes about the fatiguing qualities of turkey, beware of such claims. They may be leading you astray. For your consideration....
http://www.snopes.com/food/ingredient/turkey.asp
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2151163/
http://www.snopes.com/food/ingredient/turkey.asp
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2151163/