Herbal Tea, Coffee Consumption Tied to Lower Liver Stiffness
BOSTON, MA—Herbal tea and coffee consumption might protect the liver among healthy adults, according to findings presented at The Liver Meeting® 2016.
“High coffee consumption appears protective of liver stiffness even in individuals with no known liver disease,” reported lead study coauthor Louise J. Alferink, of the Gastroenterology and Hepatology of the Erasmus Medical Center, Rotterdam, Netherlands.
Tea and coffee consumption is ubiquitous around the world. Both contain polyphenols, caffeine, as well as other chemical components. Polyphenols and caffeine are suspected to improve liver health; for example, previous research has suggested that coffee might prevent liver cirrhosis. However, whether or not this is true for fibrosis in the general population is not known.
To find out, the research team used transient elastography (TE) to assess liver fibrosis, and compared results to coffee and tea consumption, as part of The Rotterdam Study, an ongoing prospective population-based cohort study of healthy suburbanites. Participants aged ≥45 years underwent TE and completed a 389-item food frequency questionnaire. Data from the coffee and tea consumption components of the questionnaire were then compared to liver stiffness measurements (LSM).
Clinically relevant fibrosis was defined as LSM ≥8kPa. Coffee and tea consumption were categorized as none, moderate (<3 cups per day), or frequent (≥3 cups per day) levels of consumption. Subtypes of tea consumption (green, black or herbal tea) were also recorded.
In a total of 2,424 participants, 125 (5.2%) had LSM ≥8kPa. Ninety-three percent consumed coffee and 84.7% drank tea.
The proportion of LSM ≥8kPa declined with increasing coffee consumption (7.8%, 6.9% and 4.1% for none, moderate, and frequent coffee consumption; P=0.006).
“This inverse relation between coffee intake and LSM ≥8kPa was confirmed in regression analyses even after adjustment for total energy, age, sex, body mass index, insulin resistance, ALT, steatosis, smoking, alcohol, milk and sugar use (P=0.003),” Dr. Alferink said.
Tea consumption overall did not predict LSM but in multivariate analysis, liver stiffness was lower among participants who drank herbal tea (P=0.003).
“Unlike coffee, herbal tea does not contain caffeine, which leaves room for thought whether the anti-fibrotic effects can be ascribed to polyphenols,” suggested Dr. Alferink. The proportion of steatosis was comparable among coffee categories (P=0.56) but significantly different among overall and subtypes of tea (max P=0.026). Tea consumption was not associated with steatosis after adjusting for BMI, gender, and age.
More research is needed to identify and understand the molecular mechanisms whereby coffee, herbal tea and LSM might be related, Dr. Alferink said.
Study coauthors disclosed consulting fees from AbbVie, Bristol Myers Squibb, GSK, Gilead Sciences, Innogenetics, Merck, Medtronic, Novartis, Roche, Janssen, Medimmune, ISIS Pharmaceuticals, and Tekmira, as well as other support.