Chronic liver diseases can lead to serious health complications such as kidney failure, hypertension and type 2 diabetes. But do you know that liver fibrosis, the scarring of liver tissue associated with chronic liver diseases, can affect brain health? A new study suggests the condition can reduce cognitive ability and brain volume.

In the study published in eBioMedicine, researchers have established how the brain and liver health are interconnected, adding new evidence to support the existence of the liver-brain axis.

Previous studies have shown that chronic inflammation from liver diseases can affect brain health. In the new study, researchers used data from the U.K. Biobank to understand how liver fibrosis may affect the brain. They used C-reactive protein as a marker of systemic inflammation to determine the effect of liver diseases on cognition and brain structure.

It confirmed previous findings that inflammation contributes to the link between the liver and the brain. The research team found a significant association between liver fibrosis, reduced cognitive ability and decreased gray matter volume in brain regions, including the hippocampus, thalamus, striatum and brain stem.

"There was a significant negative correlation between liver fibrosis and multiple cognitive functions, including working memory, prospective memory, and processing speed," said Rongtao Jiang, the lead author of the study. "In sum, our results support the existence of the liver-brain axis."

The study highlights the need for early surveillance of liver diseases to prevent cognitive decline and progression of diseases like dementia and Alzheimer's disease.

"Early-stage liver fibrosis is a reversible syndrome, and our current study suggests that early surveillance and prevention of liver disease may reduce cognitive decline and brain volume loss. And since we found a mediating effect of systemic inflammation, it may tell us that drugs or interventions that target inflammation may help us prevent the disease burden of liver fibrosis," Jiang added.

Dustin Scheinost from Yale School of Medicine, a senior author of the study, said the research highlights how physical, mental and brain health are interconnected. "In some ways, it's about taking care of yourself as a whole. Any piece of the puzzle you can address is probably going to have other downstream effects and benefits," Scheinost said.