I work in a field where I come into contact with many people who have Bi-Polar. Many of them are un-medicated. What I see in the people who have chosen not to medicate isn't good. I could describe what I've witnessed and been subject to, but couldn't do them justice.
My best advice is that if you or someone you love is considering medication for Bi-Polar Disorder, be patient. It might take some time to find the right combination but when you do you'll know it. It might take a combination of meds to find the right control. I have a friend that's on three different meds... two specifically for Bi-Polar, one for anxiety and depression. But her combination might not work for someone else and be unique to her situation and type of Bi-Polar.
My cousin is Bi-Polar (and autistic), and he self-medicates with alcohol and sometimes pot. He was on meds for a while, but then lost his insurance and while he said they worked well for him in the next sentence he said they sucked and were an effort for "the man" to control him. He goes through very dark, self-harming, self-destructive periods and for about 6-9 months he was homeless and living in the woods. I had no idea, and it was the winter of last year. It explained why he just dropped out of sight for a while.
I see that happen a lot too, in my line of work. There are so many people with untreated, severe neurological and mental disorders that they lose all social function, including day to day ability to live independently, and they become homeless. Some just disappear like my cousin did. Then one day if you're lucky they might pop back up, just like my cousin did. Except he's still not medicated and he moved out of state last month with no supports except his un-medicated ADHD Bi-Polar autistic fiancee and I fear for them every single day. He has anger control problems, focus problems, which he holds in check very well for me because he loves me and I help him, but it's exhausting for him.
I wish he and his fiancee would get jobs with insurance and find a good doctor and supports and get on medication again. They're about 13 states away. I worry that at some point, I'll stop seeing Facebook updates and they won't ever start up again.
So yeah... please do more than consider meds along with the dietary changes.