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Coffee consumption and risk of type 2 diabetes mellitus

2003; Elsevier BV; Volume: 361; Issue: 9358 Linguagem: Inglês

10.1016/s0140-6736(03)12586-x

1474-547X

Akihiro Isogawa, Mitsuhiko Noda, Yoshihiko Takahashi, Takashi Kadowaki, Shoichiro Tsugane,

Nutritional Studies and Diet

Rob van Dam and Edith Feskens report an inverse association between coffee intake and diabetes.1van Dam RM Feskens EJM Coffee consumption and risk of type 2 diabetes mellitus.Lancet. 2002; 360: 1477-1478Summary Full Text Full Text PDF PubMed Scopus (386) Google Scholar We have seen similar results among Japanese health check-up examinees (1916 men and 2704 women, 40 or 50 years old), residing in an urban area of our country, who are part of the Japan Public Health Center-based prospective study on cancer and cardiovascular diseases (JPHC) cohort.2Tsugane S Sobue T Baseline survey of JPHC study-design and participation rate. Japan Public Health Center-based Prospective Study on Cancer and Cardiovascular Diseases.J Epidemiol. 2001; 11: S24-S29Crossref PubMed Scopus (218) Google Scholar, 3Tsugane S Fahey MT Sasaki S Baba S Alcohol consumption and all-cause and cancer mortality among middle-aged Japanese men: seven-year follow-up of the JPHC Study Cohort I.Am J Epidemiol. 1999; 150: 1201-1207Crossref PubMed Scopus (140) Google Scholar Our cross-sectional analysis revealed that coffee intake (frequency per week or number of cups per day on a food frequency questionnaire) was inversely associated with the prevalence of fasting hyperglycaemia (fasting plasma glucose ⩾6·1 mmol/L) after adjustment for sex, body-mass index, family history of diabetes, and age, as shown in the table. We also converted number of cups into caffeine intake and got a similar result (table). This inverse association remained unchanged even after introducing a variable for sugar use and stratifying the participants into two groups—ie, those who use and do not use sugar in coffee (data not shown).TableRisk of having prevalent fasting hyperglycaemia according to caffeine intake and sourceOdds ratio (95% CI)pCoffee intake (yes/no*"No" means less than once a week.)0·614 (0·472–0·804)<0·001Caffeine from coffee (100 mg/day increase)0·910 (0·857–0·962)0·001Green tea intake (yes/no*"No" means less than once a week.)0·827 (0·592–1·179)0·277Caffeine from green tea (100 mg/day increase)1·003 (0·908–1·106)0·946Tea intake (yes/no*"No" means less than once a week.)0·949 (0·726–1·251)0·705Caffeine from tea (100 mg/day increase)0·967 (0·672–1·301)0·839Oolong tea intake (yes/no*"No" means less than once a week.)1·064 (0·833–1·362)0·621Caffeine from oolong tea (100 mg/day increase)1·078 (0·938–1·228)0·269Total caffeine intake (100 mg/day increase)0·939 (0·894–0·986)0·012* "No" means less than once a week. Open table in a new tab There were no significant correlations between prevalence of fasting hyperglycaemia and intake of three other major beverages in Japan: green tea (Japanese tea), ordinary tea (black tea), and oolong tea (a Chinese tea) in terms of either frequency or amounts of caffeine ingested (table). Finally, we saw a weaker positive correlation between fasting hyperglycaemia and total amount of caffeine intake (the sum of intake from all four beverages) than between fasting hyperglycaemia and coffee alone (table). Since coffee was the only one of the four beverages analysed that was significantly associated with the prevalence of fasting hyperglycaemia, we suggest two possible interpretations. One is that coffee itself, not caffeine, has a beneficial effect in prevention of hyperglycaemia, and that the weak association between the prevalence of fasting hyperglycaemia and total caffeine intake was incidental, since more than half of the total caffeine ingested by the participants as a whole was from coffee. The other interpretation is that even though caffeine itself exerted the effect, our method had less power to detect the effect of the caffeine contained in the other three beverages. In summary, coffee consumption has a preventive effect against diabetes not only among white Europeans, but also among Japanese individuals. Because caffeine is known to increase lipolysis4Spriet LL McLean DA Dick DJ Hultman E Caderblad G Graham TE Caffeine ingestion and muscle metabolism during prolonged exercise in humans.Am J Physiol. 1992; 262: E891-E898PubMed Google Scholar and to enhance insulin secretion,5Shi CL Effects of caffeine and acetylcholine on glucose-stimulated insulin release from islet transplants in mice.Cell Transplant. 1997; 6: 33-37Crossref PubMed Scopus (12) Google Scholar a further assessment of the benefit of caffeine (or coffee) in preventing diabetes in a prospective study would be interesting. We are very grateful to Satoshi Sasaki for helpful discussions, and also thank the staff of the Katsushika Health Center.