Hi Janey
Welcome to the forum!
I think a good place to start in your search for answers on this question would be the NRAS Helpline, telephone 0800 2987 650. They will be able to access the latest information on research through their team of medical advisors.
To my knowledge although stem cell research has come a long way in recent years and studies continue with regard to its useability in Rheumatoid patients there remains a long way to go before testing, if feasible, even begins. The state of play may be different for osteoarthritis. One of the important things to bear in mind is that Rheumatoid is not 'arthritis' per se, and is NOT a disease of the bones/joints. It is a systemic auto-immune disorder for which disease modyfying drugs are needed to bring it under control. Left to its own devices Rheumatoid can sometimes spread very quickly and cause irreparable damage both to joints and major organs.
I am pleased to hear that you have found lifestyle changes of benefit to you. In my experience it is generally accepted that dietary changes alone will not affect the outcomes of Rheumatoid disease however combined with a strict regime of suitable drug therapy significant benefits can be seen.
Congratulations on your remission; fingers crossed it lasts a good while for you
Lyn x