Diet pop/ artificial sweeteners

I have RA and recently made a decision to quit drinking diet pop and other artificially sweetened drinks. The reason had nothing to do with my RA but after a week I have noticed that my knee pain in particular has lessened. I don't know if it's a coincidence of timing or related to quitting artificial sweeteners. I've been a diet cola junky for over 30 years. Has anyone had a similar experience?