Original article Coffee consumption and health-related quality of life Esther Lopez-Garcia * , Pilar Guallar-Castillon, Luz Leon-Muñoz, Auxiliadora Graciani, Fernando Rodriguez-Artalejo Dept. Preventive Medicine and Public Health, School of Medicine, Universidad Autónoma de Madrid/IdiPAZ, CIBER of Epidemiology and Public Health (CIBERESP), Spain article info Article history: Received 11 December 2012 Accepted 6 April 2013 Keywords: Coffee Health-related quality of life Population study summary Background and aims: Understanding the effect of coffee on health-related quality of life (HRQL) would contribute to explain the mechanisms of the long-term effect of coffee on health. The aim of this study was to examine the association between coffee consumption and HRQL. Methods: Cross-sectional study conducted in 2008e2010 among 11,423 individuals representative of the Spanish population aged 18 years. Habitual coffee and food consumption was assessed with a validated diet history. HRQL was measured using the Spanish version of the SF-12 questionnaire. The analyses were performed using linear regression and adjusted for the main confounders. Results: Among men, no association was found between coffee consumption and the physical and mental composite summaries (PCS and MCS) of the SF-12. Among women, compared to those who did not consume coffee, habitual coffee drinkers showed similar scores on the PCS [beta coefficients (p value) for 1, 2, 3, and 4 cups/day: 0.49 (0.20), 0.62 (0.21), 0.50 (0.45), and 0.36 (0.59)]; but slightly better scores on the MCS [beta (p value): 1.58 (<0.001), 1.58 (0.004), 0.80 (0.31), and 1.22 (0.10)]. These results reflect mostly the consumption of non-filtered caffeinated coffee. Tea consumption and total caffeine intake did not show an association with HRQL. Conclusion: We found no evidence of an adverse effect of coffee on HRQL. These results are consistent with the null association between this beverage and several chronic diseases and all-cause mortality reported in many studies. The weak positive association of coffee with the MCS found among women needs further confirmation. Ó 2013 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. 1. Introduction There is substantial interest on the health effects of coffee because this beverage is widely consumed throughout the world. Although caffeine intake produces an acute increase in blood pressure 1 and coffee can trigger acute myocardial infarction 2 and stroke, 3 habitual coffee consumption has a null or inverse associ- ation with long-term risk of several chronic diseases (e.g. diabetes, ischemic heart disease, stroke, several types of cancer, depression, etc.) and all-cause mortality. 4e6 The mechanisms of the long-term effects of coffee are unclear. First, because it is uncertain if habitual coffee drinkers develop tolerance to the acute effects of caffeine. 7 Second, because in addition to caffeine, coffee contains hundreds of substances whose biological effects are mostly unknown. 8 Moreover, among the few substances whose effects are established, some seem to be bene- ficial (e.g., phenolic compounds, magnesium, trigonelline and qui- nides, which have antioxidant or antiinflammatory properties) 8,9 while others may be detrimental (e.g., diterpenes, which might increase total and serum LDL-cholesterol). 10 Thus, the net long- term impact of coffee on health should result from a balance of the effects of all those substances. Health-related quality of life (HRQL) represents the individual perception of the impact of health status on different spheres of life, including physical, mental and social aspects. 11 A decline in HRQL has been shown to predict increased mortality in subsequent years, while its improvement is predictive of lower mortality. 12 However, no previous study has examined the association between coffee consumption and HRQL. A positive or null association would contribute to a better understanding of the mechanisms of the long-term effect of coffee on health and would add biological plausibility to the association between coffee and lower all-cause mortality reported in many studies. 4,5 Thus, the objective of this study was to assess the association between habitual coffee con- sumption and HRQL in a representative sample of the Spanish population. * Corresponding author. Dept. Preventive Medicine and Public Health, School of Medicine, Universidad Autónoma de Madrid, Avda Arzobispo Morcillo n  4, 28029 Madrid, Spain. Tel.: þ34 91 4972738. E-mail address: esther.lopez@uam.es (E. Lopez-Garcia). Contents lists available at SciVerse ScienceDirect Clinical Nutrition journal homepage: http://www.elsevier.com/locate/clnu 0261-5614/$ e see front matter Ó 2013 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. http://dx.doi.org/10.1016/j.clnu.2013.04.004 Clinical Nutrition xxx (2013) 1e7 Please cite this article in press as: Lopez-Garcia E, et al., Coffee consumption and health-related quality of life, Clinical Nutrition (2013), http:// dx.doi.org/10.1016/j.clnu.2013.04.004