Circadian Rhythms May Be in Our Bones, Not Just Our Heads

As the days get shorter and the nights grow longer, you may be fighting to stay awake at night or to get moving in the morning. Don’t think you’re becoming a slacker, said Dr. Paula Witt-Enderby, professor of pharmacology. It’s likely caused by changing melatonin levels.

“Melatonin is known as the hormone of darkness, so its release is dependent, in part, upon the light/dark cycle,” Witt-Enderby said. “This is an important molecule in your body because it tells your body if it is daytime or nighttime and it tells your body what season it is in, winter versus summer.”

Disruptions in nighttime melatonin levels, as seen in shift workers, for example, produce adverse effects, such as a higher risk of breast, endometrial and prostate cancers as well as increases in the risk of hip and wrist fractures.

Besides reflecting melatonin’s key role in keeping the body aligned with the light/dark cycle, these disruptions and risks indicate that melatonin plays a role in cancer and bone loss protection. Witt-Enderby, in collaboration with Dr. Steven Lockley of Brigham and Women’s Hospital, Harvard University, is studying the impact of light—or lack of light—on bone rhythms in blind women to begin to understand if and how bone metabolism may be regulated by the light/dark cycle. The findings from this study, reported at October’s American Society for Bone and Mineral Research conference, may help to explain the loss of bone that occurs in shift workers. Other research Witt-Enderby has conducted shows a positive effect of melatonin on bone health.

Yet, the question remains: How do we prevent bone loss due to light exposure at night?
Witt-Enderby suggested:

• Wearing an eye mask to combat suppression of nocturnal melatonin levels
• Turning off cell phones and computers
• Removing all light sources from your bedroom
• Taking a melatonin supplement at night.

Currently, Witt-Enderby is conducting a clinical trial looking at a combination melatonin and micronutrient therapy on reversing bone loss in postmenopausal women who have osteopenia (T-score -1.0 to -2.5). Only six spots remain in this trial for those willing to participate in a one-year study. Participants will receive free bone density scans, health assessments, study supplements and parking. If interested, please contact Maria at 412.396.4296.