Diet as a Risk Factor for Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is a chronic, systemic inflammatory disease that involves primarily synovial tissues and typically affects women more than men. An exact cause has yet to be identified, but the disease is thought to manifest due to both genetic and environmental factors. The predominant theory is that RA is an autoimmune disease with environmental triggers. Recently, diet as a risk factor for RA has become of interest. The objective of this narrative review is to determine which dietary factors have an influence on developing RA by examining existing literature on this topic. A PubMed search was built using the MeSH terms: "rheumatoid arthritis," "risk factors," "diet," "nutritional status," "nutrition therapy," "nutrition assessment," "nutrition disorders," "diet, food, and nutrition," and "nutritional requirements." Articles containing a sample size of >10, published in the last 30 years, and written in English were included. Current literature has examined dietary items, such as alcohol, fruit, red meat, and caffeinated beverages, as risk factors for RA. However, the effect of each dietary item has often been variable across studies. The variation in results may be attributed to the variable categorization of each dietary item across studies, variations in the phrasing of dietary items, differing methods of data collection, and the cohort chosen. This narrative review of the literature showed that moderate alcohol consumption and increased β-cryptoxanthin are protective against developing RA. Overall, specific dietary elements and their influence on RA risk is a promising topic, and significant findings may be helpful in preventing the development of RA.