Diet and sleep patterns in newborn infants.
Level 2 - randomized trial
Individual randomized controlled trial
PubMed 6621660 · doi:10.1056/NEJM198311103091903
What was done
Twenty healthy newborn infants (2 to 3 days of age) were randomly assigned to receive an experimental feeding consisting of either tryptophan in 10% glucose or valine in 5% glucose (valine competes with tryptophan for entry into the brain). Sleep patterns during the three hours after this feeding were compared with sleep patterns observed after a feeding of standard formula (Similac).
What was found
Infants fed tryptophan entered active sleep 14.1 minutes sooner and quiet sleep 20 minutes sooner than they did after receiving formula. Infants fed valine entered active sleep 15.8 minutes later and quiet sleep 39 minutes later than after formula. The differences between the tryptophan and valine groups were statistically significant (P < 0.01 for active sleep; P < 0.005 for quiet sleep).
Why it matters
This study demonstrates in human newborns that acute dietary alterations in amino acid precursors can directly modulate central nervous system function and sleep behavior.
Limits
The sample size was very small (n = 20), and outcomes were assessed over only a single 3-hour period. The glucose concentrations in the carrier solutions differed (10% glucose for tryptophan vs. 5% glucose for valine), introducing a potential confounding factor. Blinding procedures were not detailed in the abstract.
Cited by
- supports Outside of traumatic brain injury, high doses of branched-chain amino acids may impair sleep by competing with tryptophan for uptake into the brain, potentially reducing serotonin and melatonin synthesis.