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Seasonal Melatonin May Limit MS Flare Ups

September 22, 2015

Higher levels of the hormone melatonin are linked to a lower incidence of Multiple Sclerosis during fall and winter. American and Argentinian scientists also found that treating mice with melatonin has shown to improve symptoms of the disease.

However, the study authors stressed that the findings don't necessarily mean patients with MS should self-dose high levels of melatonin, which is available in over-the-counter supplements. Rather, the research may spur a more targeted approach to MS without causing unwanted or dangerous drowsiness, they said.

"Melatonin controls the balance between pro-inflammatory and anti-inflammatory activities in the immune response," said study author Francisco Quintana, who is an associate professor of neurology at Harvard Medical School. "But the word of caution is, we're not saying MS patients should run out and start buying tons of melatonin."

Quintana and his colleagues studied a group of 139 patients with relapsing-remitting MS, a course of disease characterized by flare-ups and periods of stability. They found that participants experienced a 32 percent reduction in relapses during fall and winter compared to spring and summer.

The researchers also gave daily injections of melatonin to mice with an autoimmune disease mimicking MS. The melatonin improved symptoms in the mice and reduced levels of harmful T-cells known as Th17 cells, restoring a healthy balance of T-cells in the brain, spinal cord and organs involved in immune response, the researchers said.

The new research suggests a stronger basis for melatonin's role in controlling seasonal MS flare-ups compared to vitamin D, another environmental factor that could play a role in MS relapses, Quintana said.