The relationship between dietary sugar consumption and anxiety disorders: A systematic review.

High-sugar intake is a risk factor for chronic diseases such as cardiovascular disease and type 2 diabetes, but less is known about its role in anxiety disorders. This systematic review aimed to systematically synthesise and assess the existing evidence regarding the association between dietary sugars intake and anxiety disorders. Following PRISMA guidelines, a systematic search of PubMed, MEDLINE, Embase, APA PsycArticles and APA PsycINFO was conducted up to 19th August 2022. Study quality was assessed by the Newcastle-Ottawa scale (NOS) and the Cochrane risk of bias tool. Eleven studies (10 cross-sectional and 1 randomised controlled trial [RCT]) were included. Seven cross-sectional studies had very good quality or good quality, and the quality of the RCT was at low risk of bias. These studies examined sugar-sweetened beverages (n = 7), sugar-sweetened foods (n = 4) and/or added sugar (n = 5). The findings suggest a possible positive relationship of added sugar consumption with anxiety disorders, with age as a potential moderator in such association. No conclusions can be drawn on the associations between sugar-sweetened beverages, sugar-sweetened foods consumption and anxiety disorders. Due to the included studies being mostly cross-sectional, the conclusions drawn from the existing evidence should be interpreted with caution. The longitudinal design is warranted to investigate any causal relationship and the potential mechanisms underlying these heterogeneous results. The potential difference in effect at different ages observed in this review should be further examined.