70yr old dad has BP of 166/100. Is this severely high? He eats healthy. Dr. gave 5mg Norvasc (amlodipine). He does not like to take drugs. Any natural way to lower

Stay healthy. first the diastolic is high but not extremely high. untreated high blood pressure, could lead to cardiac and kidney problems. your DAD can exercise, lose weight, hydrate very well 6-8 bottles of water a day. no salt diet, eat healthy. monitor BP, still might have to take some medicine, the goal is to keep the BP in healthy level to avoid heart and kidney complication.
In addition to the. good advice you've already been given. Your dad can consider taking beet root juice products such as Neo 40 made by Neogenis compapn but check w/doctor first. Peace and good health.