ABSTRACT
Background:
Coffee is associated with a reduced risk of liver disease. This association is limited by important sources of confounding such as recall bias, healthy-user bias, and indirect measures of liver outcomes or health. We aimed to examine the impact of coffee consumption with liver fibrosis and steatosis in a nationally representative sample.
Methods:
We evaluated 4,510 subjects >20 years old from the 2017-2018 NHANES study that underwent both transient elastography and two 24-hour dietary recall examinations. We tested the associations between liver stiffness measurements (LSM) > 9.5 kpa or controlled attenuation parameter (CAP) and coffee consumption. We used decaffeinated coffee and tea consumption as controls. As sensitivity analysis, we included all drinks in one model, examined the impact of caffeine consumption, and adjusted for the Healthy Eating Index-2015 (HEI-2015) and sugar-sweetened beverage consumption as separate models.
Results:
The study sample described was aged 48 + 0.6 years, 73% were overweight or obese, 10.6% had diabetes, 47.5% reported participation in vigorous physical activity, and 23% drank > 2 alcoholic drinks per day. After multivariate adjustment, there was no association between coffee and controls with CAP. Subjects who drank >3 cups of coffee, but not other drinks, had 0.9 lower kPa (95% CI -1.6 – -0.1, p = 0.03). >3 cups of coffee were protective for LSM > 9.5 kpa (OR: 0.4, 95% CI 0.2 – 1.0, p = 0.05). Accounting for all beverages in the same model, only >3 cups of coffee remained independently associated with LSM (OR: 0.5, 95% CI 0.2 – 0.9, p= 0-03). Caffeine was not significantly associated with LSM at any dose. Finally, adjusting for sugar-sweetened beverage consumption and HEI-2015, coffee consumption remained associated with lower LSM. The protective nature of coffee consumption is therefore not attributable to caffeine and persists in participants regardless of their diet quality.
Conclusion:
Coffee is associated with lower liver stiffness but not steatosis as measured by CAP among US adults.
