New information on how a low-carbohydrate diet improves metabolism has been published in the journal Cell Metabolism. The findings could lead to improved treatments of non-alcoholic fatty liver disease.
“We discovered that the diet, independent of weight loss, led to rapid and dramatic decreases in liver fat and other risk factors for cardiovascular disease, and we also revealed previously unknown underlying molecular mechanisms,” says Jan Borén, professor of molecular medicine at Sahlgrenska Academy and lead author of the study.
A Swedish research team in collaboration with international partners recruited obese subjects with a high-fat content in their livers and placed them on a two-week diet specifically designed to examine the effects of reducing carbohydrate intake without reducing the number of calories.
The study team, which included researchers from SciLifeLab at the Royal Institute of Technology (KTH), analyzed clinical data and other large datasets to examine how the diet affected metabolism and intestinal bacteria. By using this approach, the researchers were able to identify possible explanations for why the subjects showed rapid and dramatic reductions in liver fat and other risk factors for cardiovascular disease.
The subjects’ diet was both low in carbohydrates and high in protein content. The researchers found that the metabolism of dangerous liver fats was strongly linked to rapid increases in B vitamins and bacteria that produce folic acid. The diet also had an effect on gene expression that was beneficial for the subjects.
“A low-carbohydrate diet like the one we used can be an effective treatment strategy for a serious health problem, while medical science continues to develop new drugs,” says Adil Mardinoglu, a systems biologist at KTH.
According to the researchers, it is important to emphasize that this type of diet does not necessarily suit everyone. For example, people suffering from hypercholesterolemia, with high blood cholesterol levels, should be cautious.
Non-alcoholic fatty liver disease (NAFLD) is a consequence of obesity experienced by about 70 per cent of all individuals with a body mass index (BMI) above 30. In one out of five cases, NAFLD progresses into non-alcoholic steatohepatitis (NASH), inflammation of the liver that can lead to cirrhosis with liver failure and liver cancer.
“Today there is no specific treatment for fatty liver disease apart from general advice to exercise and lose weight,” notes Hanns-Ulrich Marschall, professor of clinical hepatology. “Our study shows not only that a low-carbohydrate diet reduces liver fat but also how it achieves this effect, which could, in addition, be of major importance for alcoholic fatty liver disease.”