Inside every cell in the human body lies a nucleus: the organelle that stores the cell’s DNA and coordinates cell activities such as growth, metabolism, protein synthesis, reproduction, and more.  

The nucleus is complex, and within each one lies an even smaller, yet very important, structure: the nucleolus. 

Recent studies have scientists pointing to the nucleolus in anti-aging research.  This discovery began when scientists first identified a mutant gene in an earthworm that caused it to live to 46 days, 28 days longer than the oldest normal worm.  They found that the gene responsible for aging was controlled by metabolic processes, which led the focus of the study back to nucleolus.  

Adam Antebi, a cellular biologist at the Max Planck Institute for Biology of Ageing, believes that the nucleolus has an enormous part in regulating the lifespan of animals because the nucleolus plays a huge role in regulating and keeping order within the cell.  

Although the nucleolus is in charge of making ribosomes, which are the organelles that make proteins for the cell’s use, it also performs other functions.  The nucleolus is essentially the brain for the cell; it is responsible for ensuring that the whole “operation” is running smoothly. 

Dr. Antebi compares its job to that of a construction manager.

“It knows the supply chain, coordinates all the jobs of building, does quality control checks and makes sure things continue to work well,” said Dr. Antebi. 

Construction would not happen without the manager, and cells would not function without the nucleolus.

In the big picture, the lifespan of a cell is determined by how well the nucleolus manages the task of reacting to the cell’s body’s amount of nutrients and growth signals, growing or shrinking.  The more growth signals it receives, the more ribosomes it will produce.  To compensate, the nucleolus grows larger to contain them all, but this very action actually shortens the life of the cell and the organism.  

When there are less nutrients or growth signals, the opposite happens and  less ribosomes are manufactured, there is a smaller nucleolus, and a longer life expectancy for the cell.  Therefore, the lifespan of the cell derives from its nucleolus’s ability to balance.  

Furthermore, researchers have found that careful dietary choices and exercise, both key elements to a healthy lifestyle, can lead to larger nucleoli in muscle cells in people over the age of 60.  On the other hand, people with progeria, a disease that accelerates aging, tend to have larger nucleoli.

So far, Dr. Anebi and his team believe that smaller nucleoli are a hallmark of longevity, but further research is still necessary to determine if this structure’s size is just a marker or an actual cause of getting older.