Eating fish may help reduce the joint pain and swelling of rheumatoid arthritis, a new study has found.

Researchers studied 176 people in a larger health study who had had physical exams and blood tests and filled out food frequency questionnaires that indicated their consumption of various types of non-fried fish.

The study, in Arthritis Care & Research, categorized the participants into groups by fish consumption: less than one serving a month, one a month, one to two a week, and more than two a week. To rate the severity of symptoms they used a “disease activity score” that assigns a number based on the degree of swelling and pain.

After controlling for race, sex, body mass index, smoking, education, fish oil supplement use, duration of rheumatoid arthritis symptoms and other health and behavioral characteristics, they found the average disease activity score in each group declined as fish intake increased.