title: No effect of oral L-tryptophan or alpha-lactalbumin on total tryptophan levels in breast milk.
abstract: Postpartum depression (PPD) is the most common complication of childbearing with a 13% prevalence rate. Sleep disturbances are also common, particularly during early postpartum. In theory, l-tryptophan could improve sleep and reduce depressed mood in early postpartum; however, the first step in clinical development of tryptophan for use in postpartum is to measure the effect of oral l-tryptophan on its concentrations in breast milk, which is presently unknown. The aims were to investigate the effect of oral l-tryptophan and alpha-lactalbumin, a protein with high tryptophan concentration, on total and free tryptophan levels in breast milk and plasma, and to compare free tryptophan levels in breast milk with those in common infant formulas. Thirty healthy breastfeeding women were randomly allocated to receive 2g or 4g of l-tryptophan, or, 20g or 40g of alpha-lactalbumin or no supplement. Free tryptophan levels were also measured in 12 different infant formulas. Total tryptophan in breast milk was unaffected by oral administration of l-tryptophan or alpha-lactalbumin (repeated measures of ANOVA (rANOVA), group effect: p=0.93). Both l-tryptophan and alpha-lactalbumin were associated with greater free tryptophan levels in breast milk (rANOVA, group effect: p<0.001) (representing 2% of total tryptophan), but these concentrations were within the range of commonly used infant formulas. In contrast to most sleep inducing medications, l-tryptophan does not affect its total concentration in breast milk. These results support further investigation of dietary l-tryptophan and alpha-lactalbumin as part of a dietary supplementation approach to address sleep disturbances in postpartum and reduce risk of PPD.
authors.affiliation: CAMH Research Imaging Centre and Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada; Institute of Medical Science, University of Toronto, Toronto, ON, Canada.
authors.forename: Yekta
authors.initials: Y
authors.lastname: Dowlati
authors.affiliation: CAMH Research Imaging Centre and Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada; Institute of Medical Science, University of Toronto, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada.
authors.forename: Arun V
authors.initials: AV
authors.lastname: Ravindran
authors.affiliation: TransBioTech, Lévis, QC, Canada.
authors.forename: Maxim
authors.initials: M
authors.lastname: Maheux
authors.affiliation: Institute of Medical Science, University of Toronto, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada; Department of Psychiatry and Behavioral Neurosciences, McMaster University, Hamilton, ON, Canada.
authors.forename: Meir
authors.initials: M
authors.lastname: Steiner
authors.affiliation: Institute of Medical Science, University of Toronto, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada; Toronto General Research Institute, University Health Network, Toronto, ON, Canada.
authors.forename: Donna E
authors.initials: DE
authors.lastname: Stewart
authors.affiliation: CAMH Research Imaging Centre and Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada; Institute of Medical Science, University of Toronto, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada. Electronic address: Jeff.meyer@camhpet.ca.
authors.forename: Jeffrey H
authors.initials: JH
authors.lastname: Meyer
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D019540:Area Under Curve; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006801:Humans; D007768:Lactalbumin / Q000008:administration & dosage*; D008895:Milk, Human / Q000378:metabolism*; D011897:Random Allocation; D013997:Time Factors; D014364:Tryptophan / Q000008:administration & dosage* / Q000378:metabolism*; D055815:Young Adult
chemical_list: D014364:Tryptophan; D007768:Lactalbumin
keywords: Breast milk; Postpartum depression; Prevention; Tryptophan