12/02/2009 05:12 am ET Updated Nov 17, 2011

The Dark Night: Secret To Breast Cancer Prevention?

You won't find Batman, Christian Bale, the Joker, Heath Ledger or Gotham City anywhere in today's tale of the Dark Night.

Instead, you will discover the link between darkness and light, sleep and sleep disruption, and breast cancer.

October is Breast Cancer Awareness Month and our blog will be dedicated to sharing important scientific information on the prevention of this disease.

The good news is that there are a great many ways to help prevent breast cancer that are both easy and accessible to everyone. We will discover the wonderfully delicious foods that offer proven prevention benefits as well as targeted nutritional supplements backed by solid science. Other blogs will reveal what foods we must avoid to decrease our disease risk.

But today's blog is going to start with a very basic statistic that is quite surprising. Women who sleep less than six hours a night could be raising their risk of breast cancer by more than 60 percent.

According to a fascinating research study that took place in Japan, women who regularly had six hours of sleep or less every night were 62 percent more likely to have breast cancer compared to those who slept seven hours.

Melatonin is an important hormone that is secreted by the pineal gland in the brain while we sleep. It regulates our circadian rhythms (the body's internal clock). It is implicated in the regulation of sleep, mood, puberty and ovarian cycles. Many scientists believe that melatonin helps suppress estrogen levels, a causative factor in many cases of breast cancer.

One other note on sleep--an illuminating (pun intended) study has demonstrated the importance of sleeping in total darkness for many health reasons, including breast cancer reduction. It was found that women who worked night shifts, such as nurses and flight attendants, had a 60 percent higher rate of breast cancer.

The research, conducted at the National Cancer Institute and National Institute of Environmental Health Sciences, revealed an alarming finding: Exposure to light during the hours of sleep appears to aggressively promote breast cancer by shutting off the production of melatonin, which is also a strong immune system booster. According to research findings, its presence also impedes the growth of cancer tumors by as much as 80 percent.

A number of studies indicate a link between the possibility of both--night workers exposed to light upsetting circadian rhythms on the one hand and those who slept less than 6 hours also having an increased risk.

So you see, getting a good night's sleep is important for many reasons, including cancer prevention.

As an active researcher, I welcome your comments.