How Melatonin Protects Your Brain

Thanks in part to its sleep-supportive properties, melatonin plays a critical role in brain health.

“One of the main ways sleep protects the brain is by supporting the glymphatic system, which helps detoxify the brain nightly,” explains Samantha McKinney, RD, who helps lead nutrition education at Life Time. As we sleep, this system flushes out metabolic waste products that contribute to neurodegenerative diseases such as Alzheimer’s.

Melatonin is an important molecule in this “brainwashing” process, as Russel Reiter, PhD, one of the world’s leading melatonin experts, calls it. As a sleep-regulating hormone, it enhances deep, restorative sleep — when the glymphatic system is most active.

Melatonin’s antioxidant powers protect brain cells from oxidative stress and inflammation, both of which accelerate cognitive decline. Because it’s both ­water- and fat-soluble, it can cross the blood-brain barrier and directly neutralize harmful free radicals in the brain.

Melatonin’s presence in the brain can lead to cognitive benefits, especially for people with neurodegenerative conditions like ­Parkinson’s. It may even help with neuropathic pain and depression risk, says nutrition scientist Deanna Minich, PhD, CNS, IFMCP.

She sometimes calls melatonin the ­“molecule of consciousness” because it can enhance the vividness of dreams, and she notes that long-term meditators have been found to have higher levels of melatonin compared with nonmeditators.