LOS ANGELES (Dispatches)-Scientists studying how aging affects the biological clock’s control of metabolism have discovered that a low-calorie diet helps keep these energy-regulating processes humming and the body younger.
Researchers at the University of California, Irvine, and colleagues reveal how circadian rhythms -- or the body's biological clock -- change as a result of physiological aging. The clock-controlled circuit that directly connects to the process of aging is based on efficient metabolism of energy within cells.
They tested the same group of mice at 6 months and 18 months, drawing tissue samples from the liver, the organ which operates as the interface between nutrition and energy distribution in the body. Energy is metabolized within cells under precise circadian controls.
The researchers found that the 24-hour cycle in the circadian-controlled metabolic system of older mice remained the same, but there were notable changes in the circadian mechanism that turns genes on and off based upon the cells' energy usage. Simply put, the older cells processed energy inefficiently.
However, in a second group of aged mice that were fed a diet with 30 percent fewer calories for six months, energy processing within cells was more than unchanged.
"In fact, caloric restriction works by rejuvenating the biological clock in a most powerful way," Sassone-Corsi said. "In this context, a good clock meant good aging," said Paolo Sassone-Corsi, director of the Center for Epigenetics & Metabolism at the University of California.