Synopsis
Background
It has been postulated that the consumption of coffee and tea is associated with reduced liver disease; however, this relationship has not been assessed in the US on a population-wide basis.
Objectives
To investigate the association between chronic liver disease (CLD) and consumption of coffee and tea.
Design and Intervention
This study employed data from the US National Health and Nutrition Examination Survey (NHANES) 1971-1975 on coffee, tea, and alcohol consumption, and also that from the NHANES Epidemiologic Follow-Up Study. Data from a separate analysis (1982-1984) assessing more detailed drinking habits of some participants from the NHANES were also included. In both analyses, daily consumption was categorized as <1 cup, 1-2 cups, or >2 cups. Exclusion criteria included lack of data on coffee and tea consumption, jaundice, hepatomegaly, splenomegaly, and serum albumin >30 g/l. BMI was calculated for all participants and laboratory tests, including transferrin saturation, serum iron, and iron-binding capacity, were performed. Participants were followed up until 1992 or 1993; follow-up included interview and examination of death certificate or hospital records. CLD was determined by death certificate or hospital discharge record. A number of statistical tests were performed on the available data.
Outcome Measures
The main outcome measures were coffee and tea consumption and the incidence of CLD.
Results
In total, data from 9,849 NHANES participants (mean follow-up 19 years [range 0.2-22.1 years]) and 9,650 participants from the separate analysis were included. Mean daily intake of coffee and tea in the NHANES group was 2 cups (range 0-16 cups), and the mean daily consumption (in cups) for each category was 0.2 for <1 cup, 1.5 for 1-2 cups, and 4.0 for >2 cups. The risk of death or hospitalization from CLD was 1.4% at 20-year follow-up. The unadjusted risk of CLD at 20 years was 1.8% (hazard ratio [HR] 1.0) for those who drank <1 cup per day, 1.6% (HR 0.84, 95% CI 0.52-1.40) for those who drank 1-2 cups per day, and 1.1% (HR 0.46, 95% CI 0.26-0.80) for those who drank >2 cups per day (P = 0.002). The incidence of CLD was higher in participants with a BMI ≥30 (1.8%; HR 1.5, 95% CI 0.87-2.50) than those with a BMI of 25 to <30 (1.6%; HR 1.5, 95% CI 0.99-2.30) or <25 (1.2%; HR 1.0) Multivariate analysis revealed that drinking >2 cups of coffee per day reduced the risk of CLD by more than 50% compared to those who drank <1 cup per day (HR 0.43, 95% CI 0.24-0.75 vs HR 1.0; P = 0.003). The incidence of CLD in high-risk individuals (such as those with diabetes or a high alcohol consumption) drinking >2 cups per day was less than in those drinking ≤2 cups per day (1.1%; HR 0.40, 95% CI 0.23-0.68 vs 2.3%; HR 1.0; NS).
Conclusion
The consumption of coffee and tea is associated with a reduced risk of CLD.
Nat Clin Pract Gastroenterol Hepatol. 2006;3(9):482-483. © 2006
Nature Publishing Group
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