Light at Night: A Risk Factor for Breast Cancer

Two articles this week in the Journal of the National Cancer Institute reveal the risk of being exposed to light during the nighttime. Both studies concluded that light exposure at night is associated with an elevated risk of breast cancer. This risk increases the more one is exposed to light at night.

In an editorial, Dr. Johnni Hansen of Denmark commented that "all of the epidemiologic studies published so far on different indirect measures of light at night and breast cancer risk point to an increased risk."

In the first study, Dr. Scott Davis and colleagues in Seattle found that breast cancer risk was increased among people who frequently did not or could not sleep at around 1:30 am. There was an increased risk among people who had the brightest bedrooms. Graveyard (late-night) shift workers had about a 60 percent greater risk. The more years people worked this shift, the greater was their risk.

In the second study, Dr. Eva S. Schernhammer and colleagues in Boston also showed a moderate increase in breast cancer risk associated with night work.

About 10 years ago, scientists suggested that the hormone melatonin, which is produced by the pineal gland in the brain, naturally helps prevent some kinds of cancer. Your body's production of this hormone peaks at around 1:30 am. If people are awake during that time, they will have decreased melatonin levels the next day, which in turns can lead to further disturbed sleep.

While this theory became popular in alternative medicine circles, it was viewed skeptically by many conventional scientists. For instance, it is not even mentioned in the latest (2001) edition of a popular cancer textbook. These two rigorous studies in a prestigious journal now provide strong support for the melatonin theory.

What should you do with this information? First, if you work at night consider switching to daytime hours. This is particularly true if you have had a history of cancer. Whatever your working hours, you should make sure that you sleep in a dark or darkened room. If necessary, install light-blocking shades or curtains over your bedroom windows.

Second, do not keep any light-emitting devices in your bedroom. If you have a clock radio near your bed, make sure it emits only red light, which does not suppress melatonin production.

In a related issue, you should avoid close proximity to electromagnetic fields while you sleep. In experiments, these can also suppress melatonin production. Keep electric devices (such as clock radios) at least a foot or two from your head or body. Avoid using electric blankets while you sleep.

Finally, if you have trouble sleeping, think about taking a melatonin supplement. Three milligrams is the most commonly recommended dose. But note that some people are extremely sensitive to this hormone and find that one milligram or even less is enough for them. If you take melatonin at around 8 pm you will generally get drowsy by bedtime. It is very inexpensive and non-habit-forming. Melatonin may help you sleep...and have the beneficial effect of preventing some forms of cancer.

A "New" Antimicrobial Agent from Australia

For obvious reasons, antibiotics are much in the news. The question of antibiotics is also of interest to cancer patients, whose immune systems may be compromised by illness and treatment. New strategies for fighting microbes are urgently needed.

"We need to look for novel approaches to anti-microbial agents," said Dr. Christine Carson of the University of Western Australia, Perth, who attended a conference on the topic hosted by the Australian Society for Microbiology this month.

One such approach is an Australian botanical product, tea tree oil. This has been used for centuries as an antiseptic by the aborigines. They rub the plant's oily leaves on their skin to treat wounds, repel insects or fight infections. Tea tree oil has been sold in health food stores for external use for about 80 years now. It is now finally being taken seriously by scientists.

Tea tree oil is very complex, containing about 100 components. Seven chemicals called terpenes constitute 80 to 90 percent of the oil. Tea tree oil is active against many germs, including streptococci, E. coli, and various fungi, such as Candida. In a study of 30 patients who had infections that were resistant to a common antibiotic, one-third were completely cured by tea tree oil compared to just 13 percent who received conventional treatment.

In another rigorous trial of various treatments for herpes cold sores, tea tree oil was as effective as the synthetic drug acyclovir. After just 10 minutes exposure to tea tree oil, there were profound changes in bacterial cells leading to their destruction. Scientists still don't understand exactly how that happens.

Here is another example of how the medical establishment is reexamining outdated attitudes towards folk remedies and alternative medicine. Some of these treatments have a strong empirical basis. Treatments that were once dismissed as nonsense or even quackery, are now been justified through rigorous scientific testing.

Here at the Moss Reports

I have just completed a report on small cell bladder cancer, an extremely rare form of this disease. We have reports on 209 different types of cancer, and new ones are being added all the time. If you have a diagnosis of cancer, no matter how rare, we can help. Our reports, monthly updates, phone consultations, and Members Area with its question-and-answer forum can help you make difficult treatment decisions. If you are interested in ordering a report, or arranging a consultation, please go to our website, cancerdecisions.com, or contact coordinator Diane Galbo at 800-980-1234.

Till next week...Best wishes for your safety, good health and peace of mind!

Ralph W. Moss, Ph.D.