Light, Dark, Metatonin, Vitamin D, Primitive Inputs

Low light at night after sunset, a human primitive input…  Bright light at night (after sunset) shortens and reduces the amplitude of serum melatonin and vitamin D.

Many hormones follow a natural cycle based on light/dark cycles.  Below is melatonin;

The red line represents cortisol or stress hormone release. The blue line represents melatonin and growth and repair hormones

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Melatonin and breast cancer: cellular mechanisms, clinical studies and future perspectives

Stephen G. Granta1a2, Melissa A. Melana3, Jean J. Latimera1a2 and Paula A. Witt-Enderbya1a2a4 c1
a1 University of Pittsburgh Cancer Institute, University of Pittsburgh, Pittsburgh, PA 15232, USA.

a2 Center for Environmental Oncology, University of Pittsburgh, Pittsburgh, PA 15232, USA.

a3 Division of Molecular Diagnostics, Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA.

a4 Division of Pharmaceutical Sciences, Duquesne University School of Pharmacy, Pittsburgh, PA 15282, USA.

Abstract

Recent studies have suggested that the pineal hormone melatonin may protect against breast cancer, and the mechanisms underlying its actions are becoming clearer. Melatonin works through receptors and distinct second messenger pathways to reduce cellular proliferation and to induce cellular differentiation. In addition, independently of receptors melatonin can modulate oestrogen-dependent pathways and reduce free-radical formation, thus preventing mutation and cellular toxicity. The fact that melatonin works through a myriad of signalling cascades that are protective to cells makes this hormone a good candidate for use in the clinic for the prevention and/or treatment of cancer. This review summarises cellular mechanisms governing the action of melatonin and then considers the potential use of melatonin in breast cancer prevention and treatment, with an emphasis on improving clinical outcomes

The same holds true for other cancers (ie prostate cancer). It is all about the primitive inputs of our biology and how modern lifestyles interfere with these inputs. Bright light at night interfering with melatonin is one such intrusive, destructive force to our biology.

Bright light at night shortens the melatonin cycle (circadian rhythm) by three hours or when you finally shut off the lights;

Human circadian rhythm in serum melatonin in short winter days and in simulated artificial long days

Milena Burešováa, Marta Dvořákováb, Petr Zvolskýb and Helena Illnerová, a

aInstitute of Physiology, Czechoslovak Academy of Sciences, Prague Czechoslovakia Czech and Slovak Federal Republic

bResearch Psychiatric Laboratory, Medical School, Charles University, Prague Czech and Slovak Federal Republic

Abstract

Serum melatonin rhythm was studied in 6 human subjects experiencing short winter days resembling light/dark (LD) 8:16 h and in 6 subjects exposed at the same time to a long, LD 16:8 h skeleton photoperiod, with 3 h of bright light in the evening and again in the morning; 4 out of the 6 subjects entrained to the simulated summer photoperiod within 3 days. In the synchronized subjects, the nocturnal melatonin signal was 3 h shorter than in those experiencing just winter days. The data indicate that humans are able to respond to environmental day length by forming a proper endogenous photoperiodic signal.

When you submit to bright light at night you compress the cycle of melatonin. Look what snapping on the the lights at night can do in another mammal;

Reindeer kept indoors for a couple of days, in light-tight stalls, and exposed them to 2.5-hour-long periods of darkness during the normal light phase of the day. Each such 'dark pulse' resulted in a sharp rise of blood melatonin, followed by just as abrupt elimination of melatonin as soon as the lights went back on.

So bright light at night increases cancer risk by interfering with primitive inputs.

It would be like reducing the wash cycle time of the dishwasher by half and expecting the dishes to be just as clean as a normal cycle time.

The same can be said for the circadian rhythm of the hormone vitamin D. Here is what happens to postmenopausal women kept in bright light till midnight. The circadian amplitude dysfunction of vitamin D becomes obvious;

This reduced serum vitamin D hormone would also increase cancer risk.

Bright light at night (after sunset) interferes with the primitive inputs of human biology leading to disease states.

To prevent this night time lighting should be kept under 2 lux.