A glass of warm milk before bed will help you fall asleep.
This is a MYTH.
Well, actually, it’s part fact and part myth. Chemically speaking, nothing about warm milk before bed will help induce sleep. But the placebo effect of believing it can easily be strong enough to send you floating off to dreamland.
The pseudoscientific claims that milk is an effective sleep aid are rooted in the fact that an amino acid called tryptophan — notably found in milk and turkey — is thought to make people feel sleepier by increasing the brain’s levels of serotonin (which has sedative qualities).
However, in order to ingest enough tryptophan to have an actual impact on your serotonin levels, you would have to drink at least half a gallon of milk.
So, chances are, if you’ve always believed your glass of milk before bed ensures a good night’s rest, it’s the belief that’s doing the trick, and not the milk itself.