Cirrhosis: Nutritional Considerations

Malnutrition, a common complication in liver cirrhosis, is associated with poorer outcome. Consequently, a diet that provides 25 to 40 kcal/kg body weight a day is usually prescribed, and protein restriction is no longer recommended in most patients.¹

The typical management of cirrhosis involves medications (eg, lactulose) that decrease the absorption of ammonia, a compound that is a main cause of hepatic encephalopathy. Dietary changes, such as the use of vegetable protein instead of animal protein, may also lower blood ammonia levels.^2,3 Probiotic treatments may have a similar effect. Nutrition therapy, particularly with branched-chain amino acids, can also help support patients who are losing weight due to poor appetite and may improve survival.

A sodium-restricted diet is standard treatment. A 2000 mg sodium-restricted diet is effective, when combined with diuretic therapy, for controlling fluid overload in 90% of patients with cirrhosis and ascites.⁴ Evidence also indicates that sodium-restricted diets improve survival.⁵

In addition, the following interventions are under investigation for a possible role in cirrhosis prevention or management:

Low-fat diets. Mortality from cirrhosis in many countries is greater than what per capita alcohol consumption would predict.⁶ Several investigations have concluded that excess dietary fat may encourage cirrhosis progression. High intakes of total fat,⁷ saturated fat,⁸ and polyunsaturated fat6 have been implicated.

Vegetarian diets. Plant-based diets have more dietary fiber, which may reduce ammonia-related encephalopathy in two ways: first, by enhancing the use of nitrogen by colonic bacteria; and second, by facilitating nitrogen removal from the body by speeding food remnants through the intestines.³ Vegetable protein sources are also higher in arginine, an amino acid that decreases blood ammonia levels through increasing urea synthesis. They are also lower in methionine and tryptophan, amino acids that exacerbate encephalopathy through gut conversion to neurotoxic metabolites (mercaptans and oxyphenol, respectively). Clinical studies show that vegetarian diets increase the results of standard tests (eg, number connection score), improve nitrogen balance and electroencephalogram (EEG) results, and lower blood ammonia concentrations.³

Antioxidants and B-vitamins. Cirrhotic patients have significant reductions in antioxidant enzymes and lower blood levels of certain antioxidant nutrients, such as carotenoids, vitamin E, and zinc.^9-11 This is a theoretically important consideration, because oxidative stress contributes significantly to liver damage.¹² Poorer folate status is also found in persons with cirrhosis,¹³ and an estimated 50% have increased blood homocysteine concentrations.¹⁴ Elevated homocysteine is associated with liver fibrosis and cirrhosis, particularly if individuals possess the common MTHFR C677T polymorphism.^15-16 Although folate and vitamin B-6 supplements improve post-load (but not basal) blood concentrations of homocysteine,¹⁴ no data show that supplementation with B-vitamins and antioxidants alter the clinical course in cirrhosis patients. Due to a reduction in food intake and documented deficiencies of several nutrients in cirrhosis,⁹ patients should take at least a multiple vitamin with minerals that meets 100% of the dietary allowance for all vitamins and minerals.

Branched-chain amino acids and enteral feeding for malnourished patients. Protein-energy malnutrition is common, occurring in 65% to 90% of patients with cirrhosis. Blood concentrations of branched-chain amino acid serve as both indicators of nutritional status and predictors of survival.¹⁷ By interfering with brain serotonergic activity and inhibiting the overexpression of critical muscular proteolytic pathways, branched-chain amino acids, at doses of 12 to 14 grams per day, exert significant antianorectic and anticachectic effects in individuals with cirrhosis.¹⁸ In a multicenter randomized trial of 646 patients with decompensated cirrhosis, the ingestion of 12 g/day of branched-chain amino acids over 2 years was associated with decreased mortality of roughly 35%, compared with nutrition support from diet alone.19 Enteral feeding is also the recommended route for artificial nutrition in cirrhosis, and is associated with improved liver function and a lower hospital mortality rate.²⁰

Probiotic treatment. An imbalance in gut flora and bacterial translocation in cirrhosis patients contributes significantly to ammonia production, resulting in varying degrees of encephalopathy.²¹ Providing these patients with supplemental combinations of probiotics reduces blood concentrations of ammonia and endotoxin^21,22; reduces proinflammatory cytokine production, markers of lipid peroxidation; and improves liver function tests.²³ Patients with liver disease treated with a combination of probiotics (Lactobacillus plantarum) and fiber also had a lower rate of postoperative bacterial infections than those treated with selective intestinal decontamination, indicating a beneficial effect on the prevention of bacterial translocation. Additional controlled clinical trials are needed to confirm these findings. 

Orders

See Basic Diet Orders. Provide small frequent meals to help avoid nitrogen breakdown.

Liberalize diet if patient is eating poorly and/or revealing signs of malnutrition.

Sodium less than 2 grams daily.

Nutrition assessment per registered dietitian.

Daily multivitamin with minerals.

What to Tell the Family

Cirrhosis of the liver is a life-threatening chronic illness, which is ultimately terminal without transplantation. However, the management of cirrhosis may be improved with a high-fiber, low-sodium diet, thorough compliance with prescribed medications, and abstinence from alcohol.