Melatonin Slows Down Bone Breakdown

Researchers from Canada and Spain are making headway regarding the slowing down of bone breakdown. Faleh Tamimi, DDS, Ph.D., a professor in McGill’s School of Dentistry, is the leader of a research team that has just discovered that melatonin supplements make bones stronger in elderly rats and therefore, potentially, in elderly humans too.

The researchers suspected that a melatonin supplement would help regulate the circadian rhythms of the elderly rats, thus reducing the activity of osteoclasts and slowing down the process of bone breakdown. They were right on target.

Researchers at the University of Madrid, where the rats were housed, gave 20 male rats (22-month-old—the equivalent of 60-year-old humans) melatonin supplements diluted in water for 10 weeks (the equivalent of 6 years in human years). The femurs taken from the elderly rats which had received the melatonin supplements were then compared with those of a control group (which had not received the supplements) using a series of tests to measure bone density and strength.

The researchers found that there was a significant increase in both bone volume and density among the rats that had received melatonin supplements. As a result, it took much more force to break the bones of rats that had taken the melatonin supplements, a finding that suggests to the researchers that melatonin may prove a useful tool in combatting osteoporosis.

For Dr. Tamimi and his colleagues the next big question is whether melatonin is preventing or actually reversing the process of bone breakdown. Dr. Tamimi stated in the May 26, 2014 news release, “Until there is more research as well as clinical trials to determine how exactly the melatonin is working, we can’t recommend that people with osteoporosis go ahead and simply take melatonin supplements. I am applying for funding to pursue the research and we hope to have answers soon.”

Dr. Tamimi told OTW, “We were surprised with the magnitude of the effect of melatonin on the bone of old rats, and the consistency of the results. We expected to see some effect due to melatonin intake, but we didn’t expect it to be as large as we found out. It seems that melatonin could be playing a very important role in bone health when we grow older.”

Regarding future research, Dr. Tamimi noted, “We would test the drug in genetically modified animals in which melatonin receptors are selectively deleted in specific tissues such as the brain and the bones. This way we will be able to pin point the pathways used by the drug to improve bone health.”