Diet May Influence Risk of Liver Disease

Diet May Influence Risk of Liver Disease

By Kristina Fiore, Staff Writer, MedPage Today
Published: July 05, 2009
Reviewed by Zalman S. Agus, MD; Emeritus Professor
University of Pennsylvania School of Medicine and
Dorothy Caputo, MA, RN, BC-ADM, CDE, Nurse Planner Earn CME/CE credit
for reading medical news

LITTLE FALLS, N.J., July 5 -- Cholesterol intake, along with other dietary habits, may play a role in liver disease, researchers said.

Greater consumption of cholesterol was associated with a higher risk of cirrhosis and liver cancer, George N. Ioannou, MD, of the Seattle VA, and colleagues reported in the July issue of Hepatology.

Also, a diet high in protein was associated with increased liver risk, while a diet high in carbohydrates was associated with a decreased risk.

"Dietary nutrient composition is a strong predictor of hospitalization or death due to cirrhosis or liver cancer in the U.S. population," the researchers said.
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To assess dietary intake and risk, the researchers looked at data from the first NHANES survey on 9,221 patients, ages 25 to 74, who had no evidence of cirrhosis at baseline or for the first five years of follow-up. They were then followed for an additional 13 years.


Over that period, 118 developed cirrhosis and five developed liver cancer.


Those who reported a diet high in protein were at a higher risk of hospitalization or death due to cirrhosis or liver cancer (HR 1.37, 95% CI 0.8 to 2.2, P=0.001).


But those who reported a diet high in carbohydrates were at a lower risk (HR 0.42, 95% CI 0.2 to 0.8, P=0.003).


However, the researchers said these findings should be interpreted "with caution" because they did not start out with a strong a priori hypothesis about the direction of the associations.


On the other hand, they said their data regarding cholesterol consumption are "potentially the most important finding" of the study.


Cholesterol consumption was associated with a higher risk of liver disease, while serum cholesterol levels were not (P=0.007).


Those in top quartile of cholesterol consumption were more than twice as likely to develop cirrhosis or liver cancer than those in the bottom quartile, the researchers said.


The finding suggests that drugs blocking intestinal cholesterol absorption could have more beneficial effects on the liver than drugs blocking hepatic cholesterol synthesis, which lower serum cholesterol levels by up-regulation of hepatic LDL receptors, they said.


Neither fat consumption nor total calories was significantly associated with risk.


There was a weak association, which did not reach statistical significance between polyunsaturated fatty acid (PUFA) consumption and reduced risk of cirrhosis or liver cancer, but fatty acid consumption wasn't ascertained well in NHANES1, the researchers said.


"Future studies should investigate these associations with more specific ascertainment of n-3 and n-6 PUFA intake," they said.


They also noted that there were no associations between any measure of dietary composition and HCV infection.

The study may have been limited by both an absence of data on HCV infection and potential misclassification, the researchers noted.


They also noted several other limitations of the study.


"Although we simultaneously adjusted for all the dietary components that we investigated, it is possible that these dietary components may be surrogate markers for the intake of other known or unknown nutrients that could have important effects on the liver, such as dietary antioxidants." they wrote.


They also said they could not determine whether the protein intake was associated with increased risk of liver damage came from animal or plant sources.


Still, they concluded that diet "may be an important and potentially modifiable determinant of liver disease."



The study was supported by grants from the American Liver Foundation and the American Association for the Study of Liver Diseases.
The researchers reported no conflicts of interest.



Primary source: Hepatology
Source reference:
Ioannou GN, et al "Association between dietary nutrient composition and the incidence of cirrhosis or liver cancer in the United States population" Hepatology 2009; 50: 175-84.