It might. A number of laboratory and animal studies suggest that mangosteen has significant anti-inflammatory effects. And a few small-scale studies in humans indicate that the juice helps reduce blood levels of C-reactive protein (CRP). CRP is a substance associated with inflammation, which may be caused by widespread infection or disorders such as inflammatory bowel disease, lupus and rheumatoid arthritis.
But the studies that found this reduction in CRP were not conducted with people who have arthritis. And not everybody who has arthritis has an elevation in CRP. So at this point, while the data appears promising, it is still too early to say for sure what role mangosteen juice has in treating arthritis symptoms.
Mangosteen is a tropical fruit native to Southeast Asia. Despite its name, mangosteen is not related to the mango. The mangosteen fruit is the size and shape of a tangerine, with a thick, dark rind and creamy flesh. Mangosteen is marketed as a supplement, both as a juice and in capsule form.