10-20 mgs Melatonin

I take 10-20 mg of Melatonin most nights. Here is an interesting article about the breast cancer link with low levels of Melatonin. Besides taking your Vitamin D, are you taking Melatonin?


Further evidence for breast cancer-melatonin link
By Andrew Czyzewski
16 January 2009
Cancer Epidemiol Biomarkers Prev 2009; 18: 74-79

MedWire News: Postmenopausal women are at increased risk for developing breast cancer if they have low levels of the hormone melatonin, US researchers report.

The findings replicate those of a previous smaller study by the team, lead by Eva Schernhammer (Harvard Medical School, Boston, Massachusetts) showing a similar relationship between melatonin levels and breast cancer risk.
“Results from this prospective study add substantially to the growing literature that supports an inverse association between melatonin levels and breast cancer risk,” comment Schernhammer and co-author Susan Hankinson, also from Harvard Medical School.

Previous studies indicate that night-shift work - a surrogate for exposure to light at night - is associated with an increased risk for breast cancer.

Furthermore, results from animal studies and in vitro data suggest that the sleep hormone melatonin may be involved in the induction of neoplastic growth.
More recently such findings have been extended to humans, where researchers have measured melatonin levels indirectly to probe a possible association.
For the current study the researchers used data from the Nurses' Health Study cohort, which included 18,643 cancer-free women who provided morning urine samples from March 2000 through December 2002.

Measures of the melatonin metabolite, 6-sulfatoxymelatonin (aMT6s), were available for 357 postmenopausal women who developed breast cancer through May 2006, along with 533 matched control women who remained cancer free.
Schernhammer and Hankinson found that an increased concentration of urinary aMT6s was significantly associated with a lower risk for breast cancer (odds ratio for the highest versus lowest quartile of morning urinary aMT6s=0.62).

There was no apparent modification of risk by hormone receptor status of breast tumors, age, body mass index, or smoking status.

Melatonin has been available as a dietary supplement in the USA since 1993 and is used by frequent flyers for jet lag and by people who work rotating or night shifts. Whether it has any value as a preventative agent in breast cancer, however, remains to be seen.

The research is published in the journal Cancer Epidemiology Biomarkers & Prevention.