This book examines the role of circadian rhythms in aging, an emerging area of biology.  Although implicated in aging and longevity for over forty years, the richness of the ways in which the circadian system impacts aging has become evident only more recently.  The circadian system consists of a central pacemaker and a multitude of peripheral clocks, located in most cells throughout the organism. These clocks keep metabolic, physiological, and behavioral patterns in tune with the twenty-four hour day/night cycle and with each other.  Disruptions of the circadian system, such as the presence of light at night, can have profound pathological implications.  The core circadian oscillator consists of a multicomponent transcriptional feedback loop that regulates the periodicity of expression of some ten percent of the genes in the human genome.  This easily explains the broad influence of the circadian system.

Circadian dysregulation and melatonin rhythm suppression in the context of aging.- Pulmonary diseases, a matter of time.- Circadian regulation of bone.- Aging and the circadian control of the gastrointestinal system: from the brain to the gut microbiome (and back).- Circadian system and aging in rodent models.- The circadian system and aging of Drosophila.- Circadian control of mitochondrial dynamics.- Circadian rhythms and proteostasis in aging.- Circadian clocks and mTOR signaling.- Aging and the biological clock.- Developing circadian therapeutics against age-related metabolic decline.- The possible role of epigenetics in the memory impairment elicited by circadian rhythm disruption.- Circadian sleep-wake activity patterns during aging.- Effects of physical activity on circadian rhythms in the elderly.