Abstract
Our modern lifestyle involves irregular eating habits and extended periods spent indoors under artificial lighting. This lifestyle contrasts with the body's circadian rhythms and likely contributes to an increase of chronic diseases worldwide. This special issue on the circadian rhythm contains articles that deepen our understanding of the biological rhythmicity associated with health and disease. Research articles include studies on the effects of light therapy in patients with myocardial infarction and 24-h ambulatory blood pressure monitoring in Japanese women. Review articles cover the roles of micro-RNAs in colorectal cancer, the influence of light, electromagnetic fields and water on biological rhythms, and the effects of eating patterns on metabolic diseases. These studies and review articles highlight the importance of maintaining circadian rhythms and provide practical tips to improve human health.