Scientists have known for more than 70 years that the one surefire way to extend the lives of animals was to cut calories by an average of 30 to 40 percent. The question was: Why?
Now a new study begins to unravel the mystery and the mechanism by which reducing food intake protects cells against aging and age-related diseases. [..]
Researchers report in the journal Cell that the phenomenon is likely linked to two enzymes—SIRT3 and SIRT4—in mitochondria (the cell’s powerhouse that, among other tasks, converts nutrients to energy). They found that a cascade of reactions triggered by lower caloric intake raises the levels of these enzymes, leading to an increase in the strength and efficiency of the cellular batteries. By invigorating the mitochondria, SIRT3 and SIRT4 extend the life of cells, by preventing flagging mitochondria from developing tiny holes (or pores) in their membranes that allow proteins that trigger apoptosis, or cell death, to seep out into the rest of the cell.’