MM: Excess Dietary Salt Raises the Risk of Fatty Liver Disease in Lean People

A diet high in salt may contribute to the development of severe fatty liver disease even in people with a normal body weight. Scientists from Duke-NUS Medical School in Singapore have identified a mechanism in which excess salt alters fat metabolism in the liver and activates inflammatory processes. The study results were published in the journal Molecular Metabolism.

The researchers studied metabolic dysfunction-associated steatohepatitis (MASH). This is a severe form of fatty liver disease in which inflammation gradually damages the organ and can lead to fibrosis, cirrhosis, liver failure, and liver cancer.

MASH is usually associated with obesity and metabolic disorders. However, the disease is increasingly being diagnosed in people with a normal body mass index. This condition is known as “lean” steatosis. In some patients, the amount of fat in the liver is relatively small, but inflammation and tissue scarring are more pronounced.

To study this form of the disease, the scientists induced “lean” MASH in laboratory mice. The model reproduced key features of the condition: a relatively small amount of fat in the liver accompanied by pronounced inflammation and tissue damage.

The experiment showed that excess dietary salt alters the way the liver interacts with fats. In particular, fat breakdown increases while immune cells that sustain inflammation are activated. As a result, the pathological process can develop even in the absence of obesity.

According to the researchers, these findings indicate that fatty liver disease in people without excess weight may develop through a different biological mechanism than obesity-associated disease. As a result, medications may work differently in different patients.

In the next stage of the research, the scientists plan to identify early biomarkers of “lean” MASH and test drugs that could block inflammatory processes associated with excess salt.