Fatty Fish to Lower RA Risk

Rheumatoid arthritis risk in women decrease linked to fatty acids in fish

/ Author:  / Reviewed by: Chris Galloway, M.D. Beth Bolt, RPh

Even though the cause of rheumatoid arthritis remains unknown, researchers continue to find ways that could help people reduce their risk of this painful disease. A recent study found that a simple diet change might protect against the development of rheumatoid arthritis in women.

Through a population study, researchers found that women who regularly consumed fatty acids from fish were less likely to develop rheumatoid arthritis than women who did not consume very much fish.

As little as one serving per week of fatty fish like salmon reduced women's rheumatoid arthritis risk by half.

Rheumatoid arthritis results in inflamed joints. The researchers wrote that women in the study who regularly ate fish were possibly less likely to develop rheumatoid arthritis than women who didn't consume fatty fish each week because fatty acids have anti-inflammatory properties.

"Ask a nutritionist about foods rich in omega-3s."

Daniela Di Giuseppe, MSc, of the Karolinska Institutet in Sweden, and several colleagues conducted this study in order to see if there was a link between certain fatty acids and rheumatoid arthritis in middle-aged and older women.

Rheumatoid arthritis (RA) is a disease in which a person's joints and tissues are frequently irritated and inflamed. The condition can be extremely painful and can even limit movement. People with advanced RA may find it hard to perform normal tasks because of the disease's symptoms.

The development of RA can be affected by a number of genetic and environmental factors.

For this study, the researchers decided to examine long-chain n-3 polyunsaturated fatty acids, which are found in fish and fish oil. This type of fatty acid creates a substance in the body that has anti-inflammatory properties.

The researchers used questionnaires that had been sent to thousands of women born between 1914 and 1948.

The first part of the questionnaire asked the women about their diet, height, weight, income and education level. The second questionnaire, sent several years later, gathered similar information along with details about smoking, physical activity and dietary supplements.

The researchers looked at the questions about fish consumption. The subjects had reported their intake of lean fish like cod and fatty fish like salmon or mackerel. The researchers calculated how much of the fatty acids the women had been consuming on average.

The researchers then found women in the study who had newly diagnosed RA cases from 2003 to 2010.

By statistically analyzing the data, the researchers found that women who had an average daily intake of less than 0.21 grams of the long-chain fatty acids were more likely to develop rheumatoid arthritis.

Women who ate a serving of fatty fish once a week or four servings of lean fish every week for an extended period of time had a 52 percent decrease in their risk for rheumatoid arthritis.

The researchers believe that the anti-inflammatory properties associated with dietary fatty acids protect against the development of rheumatoid arthritis.

"This is a valuable study, offering one more health benefit to the growing list of benefits associated with eating omega-3 rich fish. Studying middle-aged women, a fairly moderate consumption of omega-3 rich fish was associated with a significantly smaller risk of developing rheumatoid arthritis. As with any observational study, the best statistics - and these are definitely well done - can only yield an 'association', not a causation," Dr. Deborah Gordon, a nutrition and preventive medicine expert, told dailyRx News.

"One of the things I love about this study, a jewel for careful readers: fish consumption associated with a lower risk consisted of one serving a week of nicely fatted fish such as salmon, but required four servings of lean (less optimal) fish. It is refreshing for a study to point out, even in the fine print, the health benefits associated with eating a naturally fatty protein source! In my practice, I encourage people to select healthy protein sources (wild-caught salmon, or pasture-raised beef) and to feel free eating the fat that comes with the meat, if they enjoy it: it usually contains a health value intrinsic to the fat and perfectly associated with the protein itself," said Dr. Gordon.

This study was published on August 12 in the Annals of the Rheumatic Diseases journal.

The research was funded by research grants from the Swedish Research Council, the Committee for Research Infrastructure, and from the Karolinska Institutet's Award for PhD Students. The authors disclosed no conflicts of interest.

Last Updated:
September 3, 2013