Not sure how accurate or up to date this wikipedia page is, though.
https://examine.com/supplements/curcumin/
It seems plausible that there could be something going on here, but as with most supplements there's not nearly enough data yet.
I'd suggest that the "miraculous" effects the parent describes would more likely be attributed to placebo, though. These things tend to work around the margins, not with dramatic improvements, which is why they're hard to study.
Brand I like is Bioglan, double strength. I have put maybe 30 people onto it that have all had positive effects.
A few years ago we went to Ulawatu in Bali and the chalet owner there was an old American guy Rob who had a disk injury from surfing years ago that flared up now and then and he was on some serious prescription anti-inflammatories, but they rendered him with serious cognitive difficulties. We have him some Curcumin and he said within the hour he could feel the pressure come off. When we left a few days later his Balinese wife was literally prostrate on the ground clutching feet and weeping with tears of thanks and appreciation. So if that's placebo, I'll take it anyway, but it's not.
Sick of armchair experts that read a bunch of poorly execute studies and start spouting off claims, but never actually try it. The chances of harm are very low , and you might be surprised how effective it is because my experience, and that of many others, is that it beats anything prescription, for certain injuries, hands f$cking down.
Placebo my arse.
Wikipedia is probably the last place I would check for scientific information.
The sources are this expensive review: https://pubs.acs.org/doi/10.1021/acs.jmedchem.6b00975
And this related letter by the authors summarizing the review: https://pubs.acs.org/doi/10.1021/acsmedchemlett.7b00139
High impact factor journal, at a basic scan the quote is accurate to the article, and the article uses standard methods. Authors all seem appropriately credentialled and working out of real institutions. Article itself has a high record of citation, and the constituent studies are all properly cited for you to proceed.