A compound in the beverage soothes the pain caused by the crippling condition, a study shows.
It could lead to the development of new drugs to combat the debilitating disorder that affects over 400,000 people in the UK alone.
Rheumatoid arthritis (RA) strikes when the body’s defences start to attack healthy joints - and it often affects younger patients.
In studies EGCG (epigallocatechin-3-gallate) - a chemical with anti-inflammatory properties found in green tea - reduced the ankle swelling in animals after ten days of treatment.
The researchers hope their discovery published in Arthritis and Rheumatology will be repeated in humans.
It’s believed antioxidants in the tea inhibit a gene called Cox-2 that triggers inflammation - working in much the same way as anti-inflammatory drugs.
Dr Salah-uddin Ahmed, of Washington State University, said: “Existing drugs for rheumatoid arthritis are expensive, immunosuppressive and sometimes unsuitable for long-term use.”
RA arthritis mostly affects the small joints of the hands and feet. It causes painful swelling that progresses into cartilage damage, bone erosion and joint deformity.
Dr Ahmed said: “This study has opened the field of research into using EGCG for targeting TAK1 - an important signaling protein - through which pro-inflammatory cytokines transmit their signals to cause inflammation and tissue destruction in rheumatoid arthritis.”
Green tea has been used for centuries to treat everything from headaches to depression.
The leaves are supposedly richer in antioxidants than other types of tea because of the way they are processed.
It can help burn fat, protect against heart disease, diabetes and cancer and lower blood pressure.