I second taking into consideration genetic factors. Is there a history of high blood pressure in his family?
My mother has always been low-normal weight, eaten a fairly healthy balanced diet, and always active...her blood pressure is through the roof without medication. In fact, almost every woman in her family has had blood pressure issues.
And now, I have it, too. Though I didn't realize it until I started getting chronic migraines and we started digging into what was causing them. I take a daily 10mg dose of Lisinopril, and that is enough to keep my numbers low enough to a) prevent migraines and b) keep my doctor happy, without impacting my ability to swim, bike, or run.
I'm not thrilled with the idea of a daily medication, but since I've done all of the other things the doctor has suggested (mainly changes in diet, since I was already actively exercising 4-5 times a week) I was willing to do it to get rid of the migraines I was experiencing regularly. Especially because those migraines caused me to DNS four races/events in the past two years.
For the record, my doctor wouldn't treat 150/80 with medication. He would start by saying no caffeine. Then: limited sugar, taking a look at overall added salt intake and possibly adjusting that downward (though he's not entirely convinced that salt is the blood pressure demon that it's made out to be), adding more fish to the diet, and reducing refined carb intake. Caffeine is really the big one for him, though. (Of course, I go to a doctor that thinks changes in lifestyle are better for you than taking pills. So, he saves the pills until he's seen the other changes don't/won't work for someone.)
2009 BMC Road Racer SL 01 / Specialized Ruby 155
2007 LeMond Reno / Luna Chix Team Saddle
1980-something Lotus Odyssey / Brooks Finesse
1992 Bridgestone RB-2 / Brooks B-17 Imperial
Nada Bike singlespeed / Brooks Team Pro in white