I was lowered to a 5mg dosage of lisinopril (from 10mgs) 6 months ago. All of a sudden my blood pressure has spiked again (175/90). I m 25 years old, in very good shape, and don t smoke . Recently I ve been training for an obstacle race and started jogging longer and increased my intake of bananas, oranges, grapefruit, and a potassium supplement . Could this be the cause?