They said a study of more than 400 people revealed a significantly lower intake of monounsaturated fatty acids (MUFA) and meat in the rheumatoid arthritis (RA) patients than in a control group.
“The present results indicate that MUFA intake affects RA disease activity and that increasing daily MUFA intake might suppress disease activity in patients with RA,” said researchers.
Writing in the journal Clinical Nutrition, they said a previous study had shown that the abundant MUFAs in olive oil had affected RA disease activity.
“However, some methodological aspects of that study are limited. Thus, the present study aimed to identify components of the Mediterranean diet that suppress RA disease activity in patients and provide the basis for an effective and minimally burdensome dietary intervention to achieve the same goal.”
Therefore, they analysed data from the prospective TOMORROW cohort study of patients with and without RA that started during 2010 and will conclude in 2020.
The study included 208 patients with RA and 205 age and sex matched healthy volunteers. Food and nutrient intake was assessed using a self-administered diet history questionnaire, while Mediterranean diet scores were calculated based on intake and disease activity.
The study found that Intake of MUFA, SFA, alcohol, pulses, other vegetables, total vegetables, meat, milk and other dairy products, key components of the Mediterranean diet, were significantly lower in the RA than the control group.
By assessing the disease activity score in 28 joints (DAS28-ESR) and the intake of components of the Mediterranean diet, they found a positive correlation.
“DAS28-ESR significantly correlated with MUFA/SFA intake after age adjustment. Logistic regression analysis selected high MUFA intake as an independent predictor of remission in the RA group with borderline boundary significance,” they wrote.
Furthermore, meat intake significantly and negatively correlated with a swollen joint count.
However, academics warned against increasing meat consumption to boost MUFA levels.
“Increased meat intake is associated with increased intake of SFA and specific antigens such as proteins that are thought to trigger RA symptoms. Therefore, olive and avocado oils are considered to be ideal sources of MUFA,” said the researchers, from Osaka City University.
They study concluded that increasing daily MUFA intake might suppress disease activity in patients with RA, but cautioned: “The results might not be generalizable because the study population included only Japanese participants, most of whom were women, especially elderly women, because of the epidemiology of RA.”
“Monounsaturated fatty acids might be key factors in the Mediterranean diet that suppress rheumatoid arthritis disease activity: The TOMORROW study”
Authors: Yoshinari Matsumoto, et al.