What foods should one with blood group a+ avoid?

Nothing in particula. Blood type of a person does not alter the type of diet one should consume. Rather, the average adult should attempt to eat a balanced diet encompassing a well proportioned mix of each of the macronutrients: carbohydrates, proteins, and fats. For more information on eating healthy: http://www.Mayoclinic.Com/health/nutrition-and-healthy-eating/my00431/tab=indepth.