Coffee and Tea Consumption Are Associated with Lower Incidence of Chronic Liver Disease

Background

Drs. Constance E. Ruhl and James E. Everhart from the National Institutes of Health published this study in Gastroenterology (PMID: 16344061, DOI: 10.1053/j.gastro.2005.08.053), examining the protective effects of coffee on liver health.

Study Design

Design: Cross-sectional and prospective analysis of NHANES I and follow-up Population: 5,944 participants at elevated risk for liver disease Exposure: Coffee and tea consumption (cups/day) Outcomes: Elevated ALT/AST, chronic liver disease, mortality

Key Findings

Coffee consumption and liver enzymes:

Coffee (cups/day)	Elevated ALT Risk (OR)
0	1.0 (reference)
<2	0.80
≥2	0.57 (0.42-0.77)

Coffee and GGT: Strong inverse association—more coffee = lower GGT

Tea: No significant protective effect observed

Dose-response: Protective effect increased with higher coffee consumption

Mechanistic Insights

Coffee contains protective compounds:

1. •Chlorogenic acids: Antioxidant, anti-inflammatory
2. •Cafestol and kahweol: Induce detoxification enzymes
3. •Caffeine: May have independent effects on fibrosis
4. •Polyphenols: Multiple protective pathways

Effects are NOT solely due to caffeine (decaf also protective in other studies).

Clinical Implications

Coffee consumption should not be discouraged in patients with liver disease risk:

• •Safe and potentially beneficial
• •2+ cups daily associated with significant protection
• •May reduce progression of chronic liver disease

Metabolic Health Perspective

Coffee is associated with improved metabolic parameters: lower diabetes risk, reduced fatty liver, improved insulin sensitivity. It can be part of a metabolic optimization strategy (without added sugar).