Lights at Night Linked to Breast Cancer

Reprinted by permission from THE ENVIRONMENTALIST

A study of NASA satellite data, overlaid with reported cancer statistics, has identified nighttime exposure to lighted areas as a risk factor for breast cancer:

Women who live in neighborhoods with large amounts of nighttime illumination are more likely to get breast cancer than those who live in areas where nocturnal darkness prevails, according to an unusual study that overlaid satellite images of Earth onto cancer registries.

“By no means are we saying that light at night is the only or the major risk factor for breast cancer,” said Itai Kloog, of the University of Haifa, who led the new work. “But we found a clear and strong correlation that should be taken into consideration.”

Recommendation below the fold…

The mechanism of such a link, if real, remains mysterious, but many scientists suspect that melatonin is key.

A tumor suppressing hormone long known to be impacted by the nighttime illumination, melatonin requires darkness for its synthesis and release.

Melatonin is a neurohormone produced in the brain by the pineal gland, from the amino acid tryptophan. The synthesis and release of melatonin are stimulated by darkness and suppressed by light, suggesting the involvement of melatonin in circadian rhythm and regulation of diverse body functions. (Mayo Clinic)

According to the Washington Post, the World Health Organization has been studying the hormonal impact of nighttime illumination, focusing on breast cancer rates among female night shift workers. When the studies revealed a 60% greater incidence of breast cancer among nurses, flight attendants and others, they classified such night shift work as a possible carcinogen.

Note from stormchaser:  This is not a recommendation to starting taking melatonin.  The mechanism has not been completely identified.  The Environmentalist’s recommendation is to keep one’s bedroom dark at night.  I’d add: reset your internal clock to match light and dark, so that you’re getting the maximum benefit of the body’s natural protective processes.



More on this important story, including recommendations, here.  

3 comments

  1. girlfriend lights out at night.  She’s a late night telly watcher.  DVR will now be our friend.

    I suggest all do the same until more is known about this.

    More at this link.

  2. It never truly is dark in the city even with the drapes and blinds pulled. The only time I’ve seen it dark is during blackouts. There is too much light pollution to even look up at the stars, so I wonder if the lack of darkness in cities is, indeed, to blame. I certainly find it difficult to sleep with all the glare, let alone look up at the stars.

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