Although the polymorphism was associated with lower stroke risk ( HR : 0.74 ; 95 % CI : 0.57 , 0.97 ; P = 0.029 per C allele ) , this association reached statistical significance only in the MedDiet intervention ( HR : 0.58 ; 95 % CI : 0.37 , 0.91 ; P = 0.019 in C compared with TT carriers ) , not in the control group ( HR : 0.94 ; 95 % CI : 0.55 , 1.59 ; P = 0.805 ) .