Eating fish and seafood reduces the risk of developing rheumatoid arthritis

Rheumatoid arthritis (RA) is one of the most common diseases in women and affects about 1% of the world’s population. This autoimmune disease causes chronic and systemic inflammation of the synovial tissue, pain, bone erosion, progressive destruction of cartilage, and eventually permanent joint damage.

Rheumatoid arthritis affects a patient’s quality of life, increases health care use, and affects life expectancy. So far, the exact cause of RA is not well understood; However, researchers have indicated that some genetic and environmental factors are associated with the pathogenesis of rheumatoid arthritis.

Stady: The relationship between animal meat food consumption and rheumatoid arthritis: a case-control study. Image Credit: Doucefleur /



Previous studies have reported some of the environmental risk factors that influence the development of rheumatoid arthritis, including stress, viruses, smoking, and diet. Diet, for example, can trigger rheumatoid arthritis and act as a mediator of the inflammatory response.

Several studies have reported the contribution of nutritional components to modulating the extent of inflammation and disease activity in patients with rheumatoid arthritis. These studies indicated that an animal-based diet, such as a diet containing dairy products and red meat, can exacerbate rheumatoid arthritis due to its pro-inflammatory properties.

Compared to other parts of the world, autoimmune diseases are more prevalent in western countries, which may be due to their eating habits. Western diets typically consist of a high amount of saturated and trans fats, sugar-sweetened beverages, refined carbohydrates, and low levels of omega-3 fatty acids, all of which increase the risk of developing rheumatoid arthritis.

about studying

One previous case-control study reported that high consumption of red meat increases the risk of developing inflammatory arthritis. However, another study conducted in China contradicted this finding and stated that there was no link between eating red meat and the risk of developing rheumatoid arthritis.

Many studies have also provided contradictory results, scientists recently Nutrition Journal The study sought to address this issue and determine the exact relationship between meat consumption and RA.

In this case-control study, newly diagnosed RA patients who visited a rheumatology clinic in Isfahan, Iran were enrolled. Not all assigned patients had been diagnosed with rheumatoid arthritis for more than 12 months.

Some of the eligibility criteria for participants included no prior chronic disease, no pregnancy or lactation, no history of food allergies, and no reported alcohol use.

The participants’ diet was assessed by data obtained from a semi-quantitative food frequency questionnaire (FFQ), which included information regarding the frequency, type and amount of food consumption. Anthropometric data such as body weight, height, body mass index (BMI) and waist circumference were also obtained. The authors also collected data on the socioeconomic status (SES) and demographic characteristics of the participants.


An inverse relationship between fish consumption and RA has been reported, while a significant association was observed between animal meat consumption and the risk of RA.

Importantly, a direct link between processed meat consumption and an increased risk of RA has been observed. Several studies have reported that eating processed meat boosts inflammatory factors, including C-reactive protein (CRP).

Interestingly, other types of meat, such as red meat, poultry, and organ meat, did not show any significant association with RA manifestations.

Individuals who ate more fish were less likely to develop rheumatoid arthritis. This result is consistent with previous studies indicating a strong association between fish intake and reduced risk of RA.

One previous study revealed that oily fish consumption significantly reduces the likelihood of developing RA. However, taking fish oil supplements does not appear to produce beneficial results.

A previous Swedish prospective mammographic study revealed that women who consumed one to three servings of fish per day were less likely to develop rheumatoid arthritis. Scientists believe that eating fish reduces the risk of developing rheumatoid arthritis due to the anti-inflammatory properties of fish oil. They note that the complex interaction of other fatty acids also stimulates adjuvant or anti-inflammatory activity.

Points of strength and weakness

One of the major strengths of this study is the recruitment of newly diagnosed RA patients, which reduces the likelihood of changing diets since diagnosis.

A major limitation of this study is the small sample size. In addition, information regarding participants’ dietary intake was reported, increasing the potential for error.

The majority of the participants belonged to Isfahan; Therefore, not all residents of Iran are well represented. Furthermore, the study results may have been influenced by potential confounding factors such as genetics and stress levels, which were not taken into account.


The current study strongly suggests that a higher intake of fish and seafood reduces the risk of developing rheumatoid arthritis. In contrast, high consumption of processed meat may significantly increase the risk of developing RA. In the future, these results should be validated using a large sample size that is representative of ethnic diversity and geographic locations.

Journal reference:

  • Hatami, Y.; , Aghajani, M., Burmasumi, M. et al. (2022). The relationship between animal meat food consumption and rheumatoid arthritis: a case-control study. Nutrition Journal 21(51). doi: 10.1186/s12937-022-00800-1.