REVIEW ARTICLE The regular consumption of coffee and development of type 2 diabetes mellitus Muneera Q. Al-Mssallem 1 Received: 20 September 2018 /Accepted: 5 March 2019 # Springer-Verlag GmbH Germany, part of Springer Nature 2019 Abstract Background Drinking coffee is habitually widespread around the world. Moderate coffee consumption has a beneficial health effect on the human body. However, there are controversial effects of consuming coffee on blood glucose and insulin levels in diabetic patients, which remain to be fully elucidated. Purpose The aim of this review was to clarify the relationship between coffee consumption and developing type 2 diabetes mellitus (T2DM). Methods The common internet search engines were utilized to access the abstracts and full text of articles published in English in the last 20 years. Results The association between the frequent consumption of coffee and the risk of developing type 2 diabetes has been studied intensively through epidemiologic and intervention studies. In fact, coffee is a major source of chlorogenic acids (CGAs) in the human diet. The presence of CGAs and other phenolic compounds in coffee plays a role in inhibiting glucose absorption via interference with glucose transporters and increasing insulin sensitivity. However, short-term trials confirmed the detrimental effects of heavily drinking coffee due to the presence of caffeine. Caffeine has been found to impair glucose tolerance and decrease insulin sensitivity. Conclusion Several clinical trials have confirmed the relationship between the consumption of coffee and the development of T2DM. Moderate consumption of coffee has been suggested for its long-term benefits and positive health effects. Keywords Blood glucose . Blood insulin . Caffeine . Chlorogenic acids . Coffee . Consumption . Diabetes Introduction Coffee beverage is the second most popular consumed drink in the world after water (Butt and Sultan 2011). Most people habitually enjoy consuming coffee on a daily basis for its unique aroma, flavor, mental alertness, and social engage- ment (Dórea and da Costa 2005). In fact, there are both ben- eficial and detrimental outcomes of consuming coffee that affect human health (Butt and Sultan 2011; Akash et al. 2014; Higdon and Frei 2006). The health-promoting features of coffee are often attributed to its rich phytocomponents, including caffeine and chlorogenic acids (CGAs) (Ludwig et al. 2014; Cano-Marquina et al. 2013). The biological effect of coffee constituents must reach an organ or tissue in a suf- ficient concentration and be maintained for an adequate peri- od of time in order to exhibit the beneficial or detrimental effects on the human body (Butt and Sultan 2011; Ludwig et al. 2014; Nawrot et al. 2003). Caffeine is a major pharma- cologically active compound that has been shown to possess positive and negative impacts on human health, and the bal- ance between the beneficial and detrimental effects of caf- feine depend significantly on the individual’ s susceptibility to it (Ludwig et al. 2014). Caffeine may enhance mental alertness and memory consolidation, improve attention, help to stop a decline in brain activity with old age, and reduce risk factors involved in metabolic syndromes (Ludwig et al. 2014; Borota et al. 2014; Heckman et al. 2010; Imagawa et al. 2009; Doherty and Smith 2004). However, the potential ad- verse effects of excessive caffeine intake should be consid- ered, particularly in children, pregnant women, individuals with hypertension, and diabetic patients (Nawrot et al. 2003; Temple 2009; Heckman et al. 2010). * Muneera Q. Al-Mssallem mmssallem@kfu.edu.sa 1 Nutritional Sciences Department, College of Agricultural and Food Sciences, King Faisal University, Al-Ahsa, Saudi Arabia https://doi.org/10.1007/s10389-019-01055-7 Journal of Public Health: From Theory to Practice (2020) 28:115–122 /Published online: 18 March 2019