24 September 2018

Mediterranean diet may cut risk of RA in men

Nutrition Rheumatology

Dietitians have long suspected that the Mediterranean diet has strong anti-inflammatory properties, and now they have some evidence to back that up.

A nine-year study of around 5,400 people has found that the chance of developing rheumatoid arthritis (RA) drops by about one-fifth in rheumatoid factor-positive men who have high adherence to a Mediterranean diet.

“This paper adds to the evidence that eating in the Mediterranean way may reduce the risk of RA being switched on,” Monica Kubizniak, a Sydney-based dietitian with an interest in rheumatoid arthritis, said.

The Swedish study compared around 1,700 patients with rheumatoid arthritis against two controls matched by age, sex and residential area.

Roughly 25% of study participants stuck to a Mediterranean diet of fruit, vegetables, whole grains and legumes, fish, white meat and alcohol, and cut red meat and sugar from their diet.

The Mediterranean diet has been shown to ward off death from CVD and cancer, probably by lowering blood pressure, lipids and inflammatory markers. 

Dietitians have long recommended it for prevention and management of RA, even though very little research had been done on this topic.

“We are very open in explaining to our clients that there is not enough good research specifically with the Mediterranean diet and RA,” Ms Kubizniak said.

“However, there is a lot of evidence that the Mediterranean diet may assist with managing or preventing inflammation, protecting against heart disease and reducing the risk of cancer.”

Some studies showed a link between foods in the Mediterranean diet and the reduction of the inflammatory marker CRP, the lessening of joint pain and stiffness, the improvement of physical function and weight loss, she said. 

According to the authors, previous studies might have missed the link between the Mediterranean diet and a reduction in RA risk because they didn’t examine the effect on men and women separately.

“In the current study, we found an inverse association between the Mediterranean diet and risk of RA but only among men, and only in seropositive RA,” the authors said. 

“A difference in the effect of Mediterranean diet by gender has been shown before for cardiometabolic variables, suggesting that indeed men could be more likely to be beneficially influenced by the Mediterranean diet.”

However, Ms Kubizniak said women were also likely to benefit from this pattern of eating as well. 

“Mediterranean eating has been associated in less joint pain in women,” she said.

Other studies have indicated that certain foods groups in the Mediterranean diet, such as nuts, are associated with a lower mortality from inflammatory diseases. 

Fish consumption has also been shown to reduce inflammatory proteins CRP and interleukin-6 in women, she said. 

Arthritis Research & Therapy, 9 August