A Mediterranean diet may significantly lessen the symptoms of rheumatoid arthritis, shows a small Swedish study published in the Annals of the Rheumatic Diseases. But it takes a minimum of six weeks for the diet to take effect, the study shows.
The researchers were only able to study 51 people out of a possible 300, because of the various combinations of drugs patients were taking. In the end, 26 people with stable rheumatoid arthritis were assigned to an experimental Mediterranean/Cretan, diet for three months. The remainder continued with their normal diet. Both groups were similar in terms of their weight and smoking habits.
The experimental diet used olive and canola oils as a primary source of fat. It was high in fish, poultry, fruit, vegetables, and legumes, and low in red meat and high fat dairy products.
To help patients comply with dietary requirements, they were served lunch and dinner at the hospital for the first three weeks of the three-month trial, and taught about Mediterranean food and cooking by the hospital dietician.
The patients were clinically assessed at the start of the study, at the end of the third week, after 6 weeks and again after 12 weeks. Several measures were used, including disease activity, reflected in joint tenderness and swelling, physical function, quality of life, and use of anti-inflammatory drugs. Secondary measures included biochemical indicators, pain severity, and a standard grip test.
The patients on the Mediterranean diet lost 3 kg in weight, and their cholesterol levels fell after only three weeks. But otherwise there was little difference in any of the variables measured until six weeks had elapsed, when the index of inflammatory activity started to fall in those on the Mediterranean diet.
By the end of 12 weeks, both physical function and vitality had also improved, and in total, nine out of the 14 variables had also changed for the better. There was no evidence of any changes in the group following their normal diet.
The authors caution that the numbers are small, and that a larger and longer study would be needed before definitive conclusions could be drawn. But they comment: “In theory even a minor effect that is persistent and accumulates over time might become important.”