Does Drinking Warm Milk During Bedtime Help You to Fall Asleep? What do Research Say?

Milk contains large neutral amino acids (LNAA) - valine, leucine, isoleucine, histidine, lysine, methionine, threonine, tryptophan, and tyrosine. Among these amino acids, leucine has the highest concentration, and Tryptophan the lowest . Tryptophan is a precursor to the sleep-inducing compounds serotonin (a neurotransmitter), and melatonin (a hormone which also acts as a neurotransmitter). To create a sedative effect, Tryptophan in the bloodstream need to cross the blood brain barrier into the brain where it is converted to serotinin. However, Trytophan has to compete with the other large neutral amino acids to enter the brain.

The higher the concentration of Tryptophan, and the lower the concentration of other LNAA in the blood pasma, the more tryptophan is delivered to the brain and converted to serotonin. Carbohydrate-rich, protein-free diets have been shown to raise the tryptophan-LNAA ratio.Eating a large meal of protein together with carbohydrate-rich food will stimulate the release of insulin. This cleared the other LNAAs from the bloodstream and make it easier for tryptophan to enter the brain. How much carbohydrate needed to make this happen is however, not certain. On the other hand, protein rich food lower the plasma tryptophan ratio because they contribute less tryptophan than do other LNAAs to the blood circulation.

In conclusion, consuming a glass of warm milk alone is unlikely to induce drowsiness or sleepiness, because milk does not contain a sufficient amount of tryptophan. A carbohydrate-rich snack of pastries and potato chips might just do the trick!