Researchers say fish and marine omega-3s have “no clear protective effect” against RA.
A diet rich in seafood — including things such as fish oil and krill supplements — has long been touted for people with rheumatoid arthritis (RA) and similar inflammatory conditions.
Many doctors recommend a diet heavy in fish, or even specific dietary plans such as the Mediterranean diet, for rheumatoid arthritis.
But a recent study in the medical journal BMC Musculoskeletal Disorders says otherwise.
Researchers say that increased dietary intake of fish and marine omega-3 fatty acids doesn’t necessarily have a correlated preventive or protective implication against the effects of RA.
The study used two cohorts of female participants, during which the researchers looked at intake of fish in the diet. These cohorts were made up of 166,013 women.
This was cataloged via food frequency questionnaires first at an initial baseline and then again every four years thereafter.
The scientists leading the study used this information in collaboration with medical record reviews in order to determine the presence and incidence of RA, including symptoms and the serologic status of RA, which is measured through labs and blood draws.
“Prior studies suggest that fish may be protective for rheumatoid arthritis risk perhaps through the anti-inflammatory effect of omega-3 fatty acid, but this relationship has not been clearly established,” the researchers wrote. “Therefore, we investigated fish intake and RA risk by serologic status, age of onset, and smoking using a prospective cohort study with large sample size, repeated measures of dietary intake, and lengthy follow-up.”
During their follow-up, they identified 1,080 RA cases that indicated that an increased fish intake wasn’t, in fact, necessarily associated with all RA cases. The researchers wrote that there was “no clear protective effect” of fish and marine omega-3s against RA.
These researchers also looked at the potential relationship or interactions between fish intake, RA, and smoking.