Sleepless in Park Hill
By Dr. Jacob Schor
If you're going to lay awake in bed at night, here is a great thing to worry about. It's not dark. There is so much light you can see inside your bedroom. With street lights, clock radios, porch lights, alley security lights, and the lights of the entire city reflected back to us from the sky, it doesn't get dark anymore. And this extra light is hurting us in more ways than we know.
Lately I have been reading and pondering the articles on light exposure and melatonin with growing concern. Melatonin is the hormone the brain makes in response to darkness. In non-medical terminology, melatonin is the stuff that Mr. Sandman sprinkles on us that tells us it is bedtime.
There are three phases to my worry: First, melatonin is protective against cancer in men and women. Second, melatonin is useful in treating cancer. And third, even teensy amounts of light are enough to throw off our melatonin production.
Melatonin happens to have other effects besides putting us to sleep. Research strongly suggests it has a protective effect against cancer and a therapeutic effect against existing cancers. One effect of melatonin is to decrease nighttime production of estrogen. As anything that lowers estrogen levels appears protective against breast cancer, researchers first looked for this relationship.
In May 1991, Robert Hahn of the Centers for Disease Control, after evaluating data from over 11,700 women with breast cancer reported a startling fact. He compared cancer and heart disease rates in women who were profoundly blind. His hypothesis was simple, if light increases cancer risk by disrupting melatonin, people whose eyes can't detect light should prove resistant to breast cancer. He was correct. Women whose eyes could not detect light were half as likely to develop breast cancer as women who could see.
At about the same time, Maria Feychting and her colleagues at the Karolinska Institute in Stockholm ran a similar study this time comparing men and women who were completely blind versus only visually impaired. Visual impairment did not interrupt melatonin production nor offer any protection against cancer. Completely blind men and women had a 70 percent lower cancer rate. Blindness protected men from cancers of the prostate, stomach, colon, rectum, skin, and lung. The blind women had less cancer in the breast, ovaries, and stomach. Continuing research up to the present has only confirmed these early findings.
While this research on melatonin lowering cancer risk has been going on, another line of research also occurred. A group in Italy headed by Dr. Lisonni, has experimented with giving high doses of melatonin to patients with existing cancers. It is easy to sum up his research in one sentence, giving large doses of melatonin before bed doubles the one year survival of people with otherwise untreatable solid tumors. Melatonin also increases the effectiveness of certain chemotherapy drugs.
So melatonin protects people against cancer and it is helpful to have extra melatonin if you have cancer. Let me add one more piece to this. It takes only a tiny amount of light to throw off melatonin production.
So now I lay awake at night. I've unplugged my clock radio, but it's still light enough to see as I lay there wondering how I can take out my neighbor's garage light. If it is light enough to see, I'm probably not making enough melatonin. No wonder I'm awake.
If you have to worry about something at night, what could be better?
Jacob Schor, N.D. majored in Food Science and Product Development as an undergraduate at Cornell University, and received his doctorate in Naturopathic Medicine at National College in Portland, Oregon in 1991. He served as President of the Colorado Association of Naturopathic Physicians from 1992-1999 and maintains a private practice at the Denver Naturopathic Clinic.