Eating oily fish twice a week can reduce the amount of swelling in joints, combatting symptoms of rheumatoid arthritis (RA), a new study suggests.
A team of researchers analysed data on 176 people in a larger health study, most of which were middle-aged white women who had had RA for a significant period of time and took medication.
The participants had taken part in physical exams and undergone blood tests, as well as responding to food frequency questionnaires, giving details on their intake of various types of fish and the way in which they were prepared.
The researchers also looked at the participants’ disease-activity scores. This was a measurement that factors in the number of joints which are swollen and tender, in addition to a blood marker of inflammation.
Fried fish were ignored from the study because frying reduces the amount of Omega-3 oils, which are a type of fat with anti-inflammatory properties. Existing studies have linked a consumption of fish-oil supplements with reduced pain for people with RA, but this was one of the first studies looking at the consumption of actual fish.
For those who ate fish at least twice a week, disease-activity scores were half a point lower on average compared to those who rarely or never ate fish.
Sushi and fish such as salmon, tuna and sardines were considered to be among the best choices, due to their high omega-3 content, but shellfish and fish and chips were ruled out due to their lower omega-3 content.
Many people who suffer from the disease take anti-rheumatic drugs (DMARDs) to try and control the symptom and prevent long-term joint damage, but this study could potentially pave the way for people to address their symptoms through diet rather than drugs.
While the findings appear to suggest that the more fish you eat, the less active RA will be, the team stressed that the observational study could not definitively prove a cause-and-effect relationship.
“If our finding holds up in other studies, it suggests that fish consumption may lower inflammation related to RA disease activity,” said Dr Sara Tedeschi, lead author of the study.
“This is a novel analysis of the relationship between consuming fish as a whole food rather than consuming fish oil supplements.
“Fish consumption has been noted to have many beneficial health effects, and our findings may give patients with rheumatoid arthritis a strong reason to increase fish consumption,” she continued.
The study was published in Arthritis Care & Research.