Artificial Light at Night (ALAN) Research Literature Database -- Query Results

Anisimov, V. N., Vinogradova, I. A., Panchenko, A. V., Popovich, I. G., & Zabezhinskii, M. A. (2012). Light-at-Night-Induced Circadian Disruption, Cancer and Aging. Current Aging Science, 5(3), 170–177. Abstract: Light-at-night has become an increasing and essential part of the modern lifestyle and leads to a number of health problems, including excessive body mass index, cardiovascular diseases, diabetes, and cancer. The International Agency for Research on Cancer (IARC) Working Group concluded that â€œshift-work that involves circadian disruption is probably carcinogenic to humansâ€ (Group 2A) [1]. According to the circadian disruption hypothesis, light-at-night might disrupt the endogenous circadian rhythm and specifically suppress nocturnal production of the pineal hormone melatonin and its secretion into the blood. We evaluated the effect of various light/dark regimens on the survival, life span, and spontaneous and chemical carcinogenesis in rodents. Exposure to constant illumination was followed by accelerated aging and enhanced spontaneous tumorigenesis in female CBA and transgenic HER-2/neu mice. In male and female rats maintained at various light/dark regimens (standard 12:12 light/dark [LD], the natural light [NL] of northwestern Russia, constant light [LL], and constant darkness [DD]) from the age of 25 days until natural death, it was found that exposure to NL and LL regimens accelerated age-related switch-off of the estrous function (in females), induced development of metabolic syndrome and spontaneous tumorigenesis, and shortened life span both in male and females rats compared to the standard LD regimen. Melatonin given in nocturnal drinking water prevented the adverse effect of the constant illumination (LL) and natural light (NL) regimens on the homeostasis, life span, and tumor development both in mice and rats. The exposure to the LL regimen accelerated colon carcinogenesis induced by 1,2-dimethylhydrazine (DMH) in rats, whereas the treatment with melatonin alleviated the effects of LL. The maintenance of rats at the DD regimen inhibited DMH-induced carcinogenesis. The LL regimen accelerated, whereas the DD regimen inhibited both mammary carcinogenesis induced by N-nitrosomethylurea and transplacental carcinogenesis induced by N-nitrosoethylurea in rats. Treatment with melatonin prevented premature aging and tumorigenesis in rodents. The data found in the literature and our observations suggest that the use of melatonin would be effective for cancer prevention in humans at risk as a result of light pollution. Keywords: Animals; Light-at-night; aging; cancer; cardiovascular diseases; circadian; circadian rhythm; diabetes; disruption; melatonin; shift-work http://alandb.darksky.org/show.php?record=377
Harrison, E. M., & Gorman, M. R. (2012). Changing the waveform of circadian rhythms: considerations for shift-work. Front Neurol, 3, 72. Abstract: Circadian disruption in shift-work is common and has deleterious effects on health and performance. Current efforts to mitigate these harms reasonably focus on the phase of the circadian pacemaker, which unfortunately in humans, shifts slowly and often incompletely. Temporal reorganization of rhythmic waveform (i.e., the shape of its 24 h oscillation), rather than phase, however, may better match performance demands of shift-workers and can be quickly and feasibly implemented in animals. In fact, a bifurcated pacemaker waveform may permit stable entrainment of a bimodal sleep/wake rhythm promoting alertness in both night and daylight hours. Although bifurcation has yet to be formally assessed in humans, evidence of conserved properties of circadian organization and plasticity predict its occurrence: humans respond to conventional manipulations of waveform (e.g., photoperiodism); behaviorally, the sleep/wake rhythm is adaptable; and finally, the human circadian system likely derives from the same multiple cellular oscillators that permit waveform flexibility in the rodent pacemaker. In short, investigation into untried manipulations of waveform in humans to facilitate adjustment to challenging schedules is justified. Keywords: Editorial; dysrhythmia; night shift; shift-work; split schedules; waveform http://alandb.darksky.org/show.php?record=460

Abstract: Light-at-night has become an increasing and essential part of the modern lifestyle and leads to a number of health problems, including excessive body mass index, cardiovascular diseases, diabetes, and cancer. The International Agency for Research on Cancer (IARC) Working Group concluded that â€œshift-work that involves circadian disruption is probably carcinogenic to humansâ€ (Group 2A) [1]. According to the circadian disruption hypothesis, light-at-night might disrupt the endogenous circadian rhythm and specifically suppress nocturnal production of the pineal hormone melatonin and its secretion into the blood. We evaluated the effect of various light/dark regimens on the survival, life span, and spontaneous and chemical carcinogenesis in rodents. Exposure to constant illumination was followed by accelerated aging and enhanced spontaneous tumorigenesis in female CBA and transgenic HER-2/neu mice. In male and female rats maintained at various light/dark regimens (standard 12:12 light/dark [LD], the natural light [NL] of northwestern Russia, constant light [LL], and constant darkness [DD]) from the age of 25 days until natural death, it was found that exposure to NL and LL regimens accelerated age-related switch-off of the estrous function (in females), induced development of metabolic syndrome and spontaneous tumorigenesis, and shortened life span both in male and females rats compared to the standard LD regimen. Melatonin given in nocturnal drinking water prevented the adverse effect of the constant illumination (LL) and natural light (NL) regimens on the homeostasis, life span, and tumor development both in mice and rats. The exposure to the LL regimen accelerated colon carcinogenesis induced by 1,2-dimethylhydrazine (DMH) in rats, whereas the treatment with melatonin alleviated the effects of LL. The maintenance of rats at the DD regimen inhibited DMH-induced carcinogenesis. The LL regimen accelerated, whereas the DD regimen inhibited both mammary carcinogenesis induced by N-nitrosomethylurea and transplacental carcinogenesis induced by N-nitrosoethylurea in rats. Treatment with melatonin prevented premature aging and tumorigenesis in rodents. The data found in the literature and our observations suggest that the use of melatonin would be effective for cancer prevention in humans at risk as a result of light pollution.

Keywords: Animals; Light-at-night; aging; cancer; cardiovascular diseases; circadian; circadian rhythm; diabetes; disruption; melatonin; shift-work

http://alandb.darksky.org/show.php?record=377

Abstract: Circadian disruption in shift-work is common and has deleterious effects on health and performance. Current efforts to mitigate these harms reasonably focus on the phase of the circadian pacemaker, which unfortunately in humans, shifts slowly and often incompletely. Temporal reorganization of rhythmic waveform (i.e., the shape of its 24 h oscillation), rather than phase, however, may better match performance demands of shift-workers and can be quickly and feasibly implemented in animals. In fact, a bifurcated pacemaker waveform may permit stable entrainment of a bimodal sleep/wake rhythm promoting alertness in both night and daylight hours. Although bifurcation has yet to be formally assessed in humans, evidence of conserved properties of circadian organization and plasticity predict its occurrence: humans respond to conventional manipulations of waveform (e.g., photoperiodism); behaviorally, the sleep/wake rhythm is adaptable; and finally, the human circadian system likely derives from the same multiple cellular oscillators that permit waveform flexibility in the rodent pacemaker. In short, investigation into untried manipulations of waveform in humans to facilitate adjustment to challenging schedules is justified.