Nutrition is always an adjuvant therapy and cannot replace effective pharmacotherapy, but the nutritional requirements are complex [2]. Rheumatoid arthritis (RA) is not curable through diet, but diet has an impact on cardiovascular and health-related outcomes, as well as mental health. There is initial moderate evidence for dietary components such as probiotics, vitamin D, ω3 fatty acids and increasingly for the implementation of the Mediterranean diet [22–24, 34]. From a current perspective, it is not advisable to follow strict diets (severe calorie restrictions, gluten-free, vegan), the high dropout rates indicate that they are difficult to manage in practice [28, 29]. The studies show a high risk of bias, many of them without the knowledge and participation of nutrition experts. Higher standards focusing on data accuracy and methodology, as well as long-term follow-ups are necessary. Referring to the content, the synergistic effect of different food components has to be examined [22].
