Melatonin, Magnetic Fields and Cancer

Since electricity, magnetic fields and grounding are all linked this may make sense.

As stated below melatonin blocks magnetic field induced DNA damage to cells, so melatonin reducing magnetophosphenes is totally feasible.

Melatonin and N-tert-butyl-α-phenylnitrone block 60-Hz magnetic magnetic field-induced DNA single and double strand breaks in rat brain cells

by H Lai - 1997 - Cited by 98 - Related articles

30 Jan 2007 ... Melatonin and N-tert-butyl-α-phenylnitrone block 60-Hz magnetic field-induced DNA single and double strand breaks in rat brain cells ...

ABSTRACT: In previous research, we have found an increase in DNA single-and double-strand breaks in brain cells of rats after acute exposure (two hours) to a sinusoidal 60-Hz magnetic field. The present experiment was carried out to investigate whether treatment with melatonin and the spin-trap compound N-tert-butyl- -phenylnitrone (PBN) could block the effect of magnetic fields on brain cell DNA. Rats were injected with melatonin (1 mg/kg, sc) or PBN (100 mg/kg, ip) immediately before and after two hours of exposure to a 60-Hz magnetic field at an intensity of 0.5 mT. We found that both drug treatments blocked the magnetic field-induced DNA single-and double-strand breaks in brain cells, as assayed by a microgel electrophoresis method. Since melatonin and PBN are efficient free radical scavengers, these data suggest that free radicals may play a role in magnetic field-induced DNA damage.

This study reveals that night adaptation reduces magnetophosphenes and melatonin is a dark adaptation;

Medical and Biological Engineering and Computing

Volume 18, Number 3, 326-334, DOI: 10.1007/BF02443387

Magnetophosphenes: a quantitative analysis of thresholds

P. Lövsund, P. Å. Öberg, S. E. G. Nilsson and T. Reuter

Low-frequency and transient magnetic fields of moderate flux densities are known to generate visual phenomena, so-called magnetophosphenes. In the present study, time-variable very low frequency (10–50 Hz) electromagnetic fields of moderate flux density (0–40 mT) were used to induce magnetophosphenes. The threshold values for these phosphenes were determined as a function of the frequency of the magnetic field both in normal subjects and colour defective ones. Maximum sensitivity occurred at a frequency of approximately 20–30 Hz, and with broad-spectrum light the threshold flux density was 10–12 mT. The threshold values were found to be dependent upon the intensity and the spectral distribution of the background light. Sensitivity decreased during dark adaptation. In certain respects deutans differed from subjects with normal colour vision. Possible mechanisms for generation of magnetophosphenes are discussed. The present magnetic threshold curves show a close resemblance to corresponding curves obtained by electric stimulation at various frequencies provided the electric thresholds are divided by the a.c. frequency. These problems are under current investigation in our laboratory. This is in full agreement with the assumption that the fluctuating magnetic field affects retinal neurons by inducing currents which polarise synaptic terminals.

The first thought that crosses my mind is that melatonin must have an effect that down regulates the magnetic influence inducing magnetophosphenes. Although the inverse is true of magnetic fields reducing melatonin levels.

This also indicates that disturbing melatonin’s circadian amplitudes or cycle durations with bright light at night, or artificial magnetic fields at night would increase cancer risk by allowing more DNA damage.

http://www.ncbi.nlm.nih.gov/pubmed/8098713
Static and extremely low frequency electromagnetic field exposure: reported effects on the circadian production of melatonin.

The mechanisms whereby non-visible electromagnetic fields influence the melatonin forming ability of the pineal gland remain unknown; however, the retinas in particular have been theorized to serve as magnetoreceptors with the altered melatonin cycle being a consequence of a disturbance in the neural biological clock, i.e., the suprachiasmatic nuclei (SCN) of the hypothalamus, which generates the circadian melatonin rhythm.

So on a related front does the ionosphere protect us from magnetic cellular damage during the day, and melatonin do a similar job at night when the magnetosphere above is weaker?

But the sun's energy varies and this changes the ionosphere. When sunspot activity increases the solar output, it becomes more ionized. It shimmers with electric currents and it absorbs the radio waves it normally reflects. It gains extra magnetism and upsets compasses by competing with the earth's magnetic poles. And some of its surplus energy glows like the rare gases in a fluorescent lamp and We see the Northern Lights.

So is the ionosphere the equivalent of active magnetic shielding in the daytime for the biology beneath it?

A magnetic field can be thought of as a force that has both strength and direction. If it is met with an equal force of exactly opposite direction, the forces will cancel and the net force will be zero. This is the basic principle of active cancellation. Fundamental principles of physics are applied in the real world to solve a problem. The term "cancellation" is sometimes taken to mean complete elimination, but this is never achieved. Rather, EMF cancellation efficiencies of 65% to 90% are typical.

I would infer that the ionosphere and changes in it during sun side exposure act as magnetic shielding to some degree. Melatonin fills the gap at night when both the ionosphere and magnetosphere are weaker.

I believe the linkage of this to the circadian rhythm of vitamin D may be paramount.  Vitamin D repairing damage, while melatonin prevents damage.

Volume 13, Issue 4, Pages 257-264 (August 2009)



Melatonin, sleep disturbance and cancer risk

David E. Blask


SUMMARY


The pineal hormone melatonin is involved in the circadian regulation and facilitation of sleep, the inhibition of cancer development and growth, and the enhancement of immune function. Individuals, such as night shift workers, who are exposed to light at night on a regular basis experience biological rhythm (i.e., circadian) disruption including circadian phase shifts, nocturnal melatonin suppression, and sleep disturbances. Additionally, these individuals are not only immune suppressed, but they are also at an increased risk of developing a number of different types of cancer. There is a reciprocal interaction and regulation between sleep and the immune system quite independent of melatonin. Sleep disturbances can lead to immune suppression and a shift to the predominance in cancer-stimulatory cytokines. Some studies suggest that a shortened duration of nocturnal sleep is associated with a higher risk of breast cancer development. The relative individual contributions of sleep disturbance, circadian disruption due to light at night exposure, and related impairments of melatonin production and immune function to the initiation and promotion of cancer in high-risk individuals such as night shift workers are unknown. The mutual reinforcement of interacting circadian rhythms of melatonin production, the sleep/wake cycle and immune function may indicate a new role for undisturbed, high quality sleep, and perhaps even more importantly, uninterrupted darkness, as a previously unappreciated endogenous mechanism of cancer prevention.

Please see this paper for more information;

Lighting for the human circadian clock: recent research indicates that lighting has become a public health issue

Stephen M. Pauley

P.O. Box 3759, Ketchum, ID 83340, USA

Received 18 December 2003; accepted 23 March 2004