The inflammatory potential of the diet, as measured by the Dietary Inflammatory Index (DII®), has been repeatedly shown to be associated with various inflammatory markers and mental and physical health outcomes. Of specific importance, several cross-sectional studies revealed mixed results regarding the correlations between the DII and sleep outcomes. Hence, in the current paper, a systematic review that examines the associations between the DII, sleep duration, and sleep quality was performed. The PubMed database was systematically searched for studies published up to November 2023 following PRISMA guidelines. Only cross-sectional studies that assessed the DII, sleep duration, and sleep quality across healthy and unhealthy cohorts were included. Eleven and seven studies were included in the systematic review for sleep quality and duration, respectively. The results of the present systematic review show that pro-inflammatory diets may be associated with poor sleep outcomes (duration and quality); however, as the current literature is inconsistent and limited, further cross-sectional studies in larger cohorts are necessary to (i) explore this relationship to address this heterogeneity and (ii) explore populations that are more sensitive to diet-induced inflammation.
Keywords: dietary inflammatory index; inflammation; nutrition; sleep; systematic review.