Mediterranean diet and incidence of rheumatoid arthritis in women.

TLDR: The association between a Mediterranean dietary pattern, as measured by the Alternate Mediterranean Diet Score (aMed), and risk of incident rheumatoid arthritis (RA) in US women is examined.

Abstract: The traditional Cretan Mediterranean diet characterized by a high consumption of fruit, vegetables, whole grains, legumes, fish, olive oil, less red meat and moderate alcohol is generally regarded as a healthy diet pattern (1) A meta-analysis of prospective cohort studies showed that greater adherence to a Mediterranean diet was associated with significantly lower mortality rate from cardiovascular disease, lower incidence of cancer, Parkinson’s disease and Alzheimer’s disease (2) It has been suggested that the beneficial effects of the Mediterranean diet pattern are mediated through improvements of inflammatory markers, lipid profile and blood pressure (3–5) Several randomized controlled clinical trials have shown a beneficial effect of Mediterranean diet intervention on physical function and vitality among patients with existing RA (6,7) This beneficial effect was found to be associated with improved fatty acid profile but not related with levels of plasma antioxidants (8,9) Several case-control studies suggested that higher consumption of fish, olive oil and cooked vegetables all of which were key components of the Mediterranean diet was associated with reduced risk or lower severity of RA (10–12) However, recall bias may be a particular critical issue in the dietary assessment because individuals with RA may be more likely to misreport their actual food consumption in the past The case-control design is also unable to measure the long-term effects of certain dietary factors Reverse causation may be a possible bias in case-control studies because individuals with early symptoms might change their usual diet In most cases, many important time-varying confounders are rarely sufficiently controlled To the best of our knowledge, no previous prospective cohort studies have evaluated the association between the overall Mediterranean dietary pattern and risk of developing RA We therefore investigate the relationships between the Mediterranean diet dietary pattern represented by Alternate Mediterranean Diet Score (aMed) (13)and RA risk in 2 well-established large cohorts of middle-aged and old women, controlling for a series of lifestyle and dietary factors