The circadian clock operates the body and organs as intrinsic time keeping machinery to preserve homeostasis in response to the changing environment. Food is known to influence clocks in peripheral tissues but it has been unclear how the lack of food influences clock function and the body.
Fasting influences the circadian clock and fasting driven cellular responses which work together to achieve fasting specific temporal gene regulations, such as skeletal muscle appears to be twice as responsive to fasting as is the liver, explains Paolo Sassone-Corsi who first showed the circadian rhythm metabolism link some 10 years ago, identifying metabolic pathways through which circadian proteins sense cell energy levels.
Mice were subjected to 24 hour periods of fasting; while fasting mice were observed to exhibit a reduction in oxygen consumption, respiratory exchange, and energy expenditure, of which all were completely abolished by refeeding, parallelling results observed in humans.
The genome may be primed by fasting to more permissive states to anticipate upcoming food intake and drive a new rhythmic cycle of gene expression via reorganization of gene regulation; meaning fasting is able to reprogram a variety of cellular responses, which in a timed manner optimal fasting may be strategic to positively affect cellular functions, benefit health, and help to protect against aging associated diseases.
New paths of investigation have been opened by this study which may lead to the development of nutritional strategies to improve human health.
