How to lower my diastolic pressure?

Had my physical the other day, and BP was 120/90 and 112/90.  I'm used to the lower number being 83-85.

On the the nurse practicioner said was that the lower number is hard to fix with diet and exercise.  I really don't want to get on medication.  Is there anything I can do that might help?  BTW, I typically will not take any supplement, suggestions of ginko, fish oil or green tea extracts will be appreciated, but not followed, although I will drink green tea and eat fish instead.

So far, the only thing I have found is tomato juice and cayenne pepper might help.  Ick, but its worth a shot.