The benefits of turmeric have been publshed in the media and discussed in medical columns for a decade or more.
The link is only one organisation's opinion, albeit a reputable one and says nothing beyond the standard anodyne 'probably works but don't blame us if it doesn't'. Certainly nothing to warn people off.
I take turmeric as part of a set of supplements supplied by Univite and, while I must obviously have some arthritis at my age (nearly 80), since it is yet to cause me any problems, before or since taking turmeric, I can make no judgement on its efficacy.