Food in sight? The liver is ready!

Key Takeaways

  • A study shows that a group of nerve cells in the brain prepares the liver to adapt for sugar metabolism a few minutes after mice smell and see food. 
  • The findings could open up new avenues for the treatment of type 2 diabetes. 

What happens in the body when we are hungry and see and smell food? A team of researchers at the Max Planck Institute for Metabolism Research investigated this question by looking at mitochondria in the livers of mice that could only see and smell food without eating it. (Mitochondria, often referred to as the powerhouses of the cell, help turn the energy we take from food into energy the cell can use.) They found that after just a few minutes, processes in liver mitochondria that prepare it for sugar metabolism, normally stimulated by food intake, were activated.  They further found that this is mediated by a previously uncharacterized modification that regulates the activity of a mitochondrial protein, which affects the sensitivity of the liver to insulin. The researchers have thus discovered a new signaling pathway that regulates insulin sensitivity in the body. The findings, published in the journal Science, could open up new avenues for the treatment of type 2 diabetes.

The researchers then looked at the role of the brain in this process and discovered that the effect on the liver is mediated by a group of nerve cells that are activated within seconds by the sight and smell of food, signaling the liver to prepare for the incoming nutrients. Remarkably, they found that the activation of these neurons alone is sufficient to adapt the mitochondria in the liver, even in the absence of food. 

Jens Brüning, head of the study and director of the Max Planck Institute for Metabolism Research, said, “Our study shows how closely the sensory perception of food, adaptive processes in the mitochondria and insulin sensitivity are linked. Understanding these mechanisms is also important because insulin sensitivity is impaired in type 2 diabetes mellitus.”


Max Planck Institute for Biology of Ageing,  ScienceDaily, April 25, 2024; see source article