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- Tea (Camellia sinensis, Theaceae)
- Coffee (Coffea arabica, Rubiaceae)
- Caffeine
- Liver Disease
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Date:
11-13-2015 | HC# 051532-532
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Re: Coffee and Caffeine Intake Are Associated with Lower Risk for Advanced Hepatic Fibrosis in Patients with Hepatitis C
Khalaf
N, White D, Kanwal F, et al. Coffee and caffeine are associated with decreased
risk of advanced hepatic fibrosis among patients with hepatitis C. Clin Gastroenterol Hepatol. August 2015;13(8):1521-1531.e3.
One
of the most popular beverages worldwide, the consumption of coffee (Coffea arabica, Rubiaceae) is associated
with a number of health benefits, including protection against the development
of liver injury (hepatoprotection). Also, there is an inverse association
between coffee consumption and hepatocellular carcinoma with or without chronic
hepatitis C virus (HCV) infection. These authors used data from a
cross-sectional study among U.S. veterans with chronic HCV infection to investigate
the association between caffeinated and decaffeinated coffee, tea (Camellia sinensis, Theaceae), and soda intake and the development of
HCV-related advanced liver fibrosis. Their secondary objective was to determine
the extent to which insulin resistance mediates the association between
caffeine intake and the severity of liver fibrosis.
The
study was conducted at the Michael E. DeBakey Veterans Affairs Medical Center
in Houston, Texas. Participants were veterans aged 18 to 70 years with confirmed
HCV viremia who were prospectively recruited from a dedicated HCV clinic at the
medical center between January 5, 2009 and November 30, 2013. The participants
were not receiving antiviral therapy at the time of recruitment.
At
baseline and after 12 weeks, participants underwent fasting blood draws for
clinical laboratory tests, had anthropometric measurements taken, and body mass
index (BMI) scores calculated. They completed a detailed questionnaire about
their lifetime use of alcohol, tobacco (Nicotiana
tabacum, Solanaceae), injection drugs, marijuana (Cannabis sativa, Cannabaceae), and other recreational drugs, as
well as the presence of comorbid conditions, such as diabetes mellitus. All
participants were scored using the Model for End-Stage Liver Disease (MELD) instrument,
which assesses the severity of chronic liver disease.
The
participants also provided information on their intake of caffeinated and
decaffeinated coffee, tea, and carbonated soda, and their use of creamers and
sweeteners. Cumulative lifetime exposure to coffee was determined by their
reported daily intake in each decade of life starting with the 20s. For assessing
average caffeine content, the authors estimated 137 mg for each 8 oz cup of coffee,
30 mg for each 8 oz cup of tea, 46 mg for each 12 oz can of caffeinated soda,
and 0 mg for decaffeinated beverages.
The
exposure variables were caffeinated and decaffeinated coffee intake, tea
intake, and soda intake, and caffeine intake overall and from each beverage.
The main outcome variable was advanced hepatic fibrosis as scored by using the FibroSURE
test, which estimates the level of liver fibrosis and inflammation.
The study included
910 veterans with chronic HCV infection. Based on FibroSURE scores, 342 (37.6%)
had advanced fibrosis (AF); the remaining 568 (62.4%) with mild fibrosis served
as controls for the analysis. Most of the participants were male (98%), African-American,
and chronic alcohol users. Those with AF were older (average, +1.8 years), had
a higher BMI, and were more likely to have type 2 diabetes mellitus, metabolic
syndrome, and higher MELD scores than the controls. Among nondiabetic participants, AF cases were more likely than controls
to be insulin resistant based on a baseline fasting homeostasis model
assessment-insulin resistance (HOMA-IR) score of ≥ 3. They were also more
likely to have received prior HCV antiviral therapy. Though none were receiving
treatment at the time of the study, all participants had detectable HCV RNA
levels, confirming the presence of HCV in the blood.
In
terms of liver inflammation, 252 participants (27.7%) were classified as
advanced inflammatory activity cases and 658 (72.3%) were classified as mild
inflammatory activity controls based on FibroSURE scores. There was no
association between caffeine intake and severity of inflammation.
Most
participants (54.6%) reported drinking some caffeinated coffee within the year
before the study, with 47.2% drinking 1 or more cups daily. The controls had a higher average daily intake of caffeinated
coffee compared with the AF cases (P=0.038) and more controls than AF cases
reported drinking an average of 1 or more cups daily (P=0.045).
About
70% of participants reported drinking caffeinated tea within the preceding
year; 22.7% consumed 1 or more cups daily. Tea intake, both caffeinated and
decaffeinated, was not significantly different between the AF cases and
controls. However, among the 413 non-coffee drinkers, caffeinated tea use was more
common among controls than among AF cases (P=0.03).
There
was no association between any consumption of caffeinated or decaffeinated soda
and AF. Although consuming ≥ 1 can of caffeinated soda daily was significantly
associated with a decreased risk for hepatic fibrosis (P=0.015), this
association was reduced after
adjusting for age, BMI, and alcohol use, and for MELD score and the presence of
metabolic syndrome (P=0.047). And it was further attenuated when adjusted for
diabetes and HOMA-IR scores (P=0.063). In addition, among the subset of
non-coffee drinkers, intake of ≥ 1 can of caffeinated soda was not significant.
Overall,
average daily caffeine consumption from all beverages was higher in the
controls (273.8 mg) than in the AF cases (218.2 mg) (P=0.013), as was the
average daily intake of caffeine from coffee (P=0.028). Caffeine was consumed
mostly from coffee, followed by soda and then tea. Stratified by dose,
participants consuming ≥ 100 mg caffeine daily from any source had a significantly
reduced risk of AF (P=0.014), as did those consuming ≥ 100 mg caffeine daily
from coffee (P=0.035); however, the association was not significant among non-coffee
drinkers consuming ≥ 100 mg caffeine daily. The average daily intake of coffee
in prior life decades was not significant.
There
were no significant associations between AF and the use of creamers/whiteners (37%
of the participants) or sweeteners (23.8% of the participants).
Among
the 650 nondiabetic participants, those with a HOMA-IR value ˂ 3 (in the normal
range) were significantly more likely to consume more than 100 mg of caffeine
daily than were the participants with HOMA-IR values of ≥ 3 (P=0.012). This
association between caffeine intake and decreased risk of insulin resistance was
significant after adjusting for age, BMI, and alcohol use (P=0.022); MELD score
(P=0.024); and the presence of metabolic syndrome (P=0.017).
An
average daily intake of 100 mg or more of caffeine from all sources was
associated with a significantly decreased risk for AF (P=0.02) after adjusting
for age, alcohol use, and BMI, and after adjusting for MELD scores in a second
multivariate model. In a third model, adjusting for insulin resistance
minimally reduced the association; however, the association between caffeine
intake and decreased risk for AF remained significant after adjusting for the
presence of metabolic syndrome (P=0.014).
In this study, an
average daily intake of ≥ 100 mg of caffeine was associated with a lower risk
for advanced hepatic fibrosis in patients with chronic HCV infection. In
non-coffee drinkers, daily caffeinated tea intake (but not caffeinated soda) was
also associated with decreased risk of progressive liver disease. Overall,
consuming caffeinated coffee or caffeinated tea is more beneficial for patients
with HCV than consuming other caffeinated beverages or decaffeinated coffee.
"If validated in
other HCV-infected populations in the United States, our results suggest that a
relatively low (and therefore potentially more tolerable dose) of caffeine,
particularly from caffeinated coffee and possibly from tea, may convey a
substantial reduction in fibrosis progression." The authors conclude that "prospective studies are warranted to determine the optimal dose and
preparation of caffeinated beverage intake that could be safely and tolerably
recommended for prevention of progressive liver disease in HCV patients in
routine clinical practice."
—Shari Henson
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