Diet: Protein defats the liver

Christiane Fux studied journalism and psychology in Hamburg. The experienced medical editor has been writing magazine articles, news and factual texts on all conceivable health topics since 2001. In addition to her work for, Christiane Fux is also active in prose. Her first crime novel was published in 2012, and she also writes, designs and publishes her own crime plays.

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Fatty liver diseases are common. What few people know: More often than high alcohol consumption, other factors are responsible - above all malnutrition and obesity. A low-calorie diet melts the dangerous fat deposits in the liver - especially if it contains plenty of protein.

A team led by Andreas Pfeiffer, head of the Endocrinology Clinic at the Charité, has investigated how the protein content of food influences the amount of liver fat. To this end, 19 very obese volunteers were given either a high or low protein diet for three weeks.

Liver defatting treatment

On average, the study participants in both groups lost a total of around five kilograms. However, the effect of the respective diet on the liver was very different: While the liver fat content in the protein-rich group fell by around 42 percent, the amount of fat in the liver of the protein-poor group remained unchanged despite the diet.

The researchers were able to determine this using tissue samples from the organ. These were taken from the subjects after the diet, during a so-called bariatric operation. The digestive tract is rebuilt in such a way that significantly less food can be absorbed by the body.

Influence on gene activity

Extensive analyzes of the gene activity in the liver cells of the samples confirmed which mechanisms were responsible for the different effects of the diets. They showed that numerous genes that are responsible for the absorption, storage and synthesis of fat in the liver were less active after a high-protein diet than after a low-protein diet.

"If the results are confirmed in larger studies, the recommendation for an increased intake of protein, together with a healthy, low-fat diet as part of an effective fatty liver therapy, could find its way into medical practice," says study leader Pfeiffer.

Consequences of fatty liver

A non-alcoholic fatty liver is often associated with obesity, type 2 diabetes, high blood pressure and disorders of the fat metabolism. The causes of illness range from an unhealthy lifestyle with an excess of very fatty and high-sugar foods, a lack of exercise to genetic components.

If left untreated, non-alcoholic fatty liver can lead to cirrhosis of the liver with life-threatening consequences.

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