RESUMO
BACKGROUND: Expensive lactation cookies (LCs) are marketed as milk boosters; however, their effectiveness remains unknown. OBJECTIVES: The objective of this study was to evaluate the effectiveness of the 1-mo daily intake of LCs on changes in objective and subjective milk production and breastfeeding self-efficacy. METHODS: This is a 1-mo, randomized controlled trial among 18-45-y-old exclusively lactating parents of healthy, term, 2-mo-old infants living in the United States from March to December 2021. Participants (n = 176) were randomly assigned to eat daily 56.5 g of either LCs with "galactagogues" (oatmeal, brewer's yeast, flax seeds, and fenugreek) or conventional cookies containing similar weight, calories, and presentation but lacking galactagogues. The primary outcome was baseline-to-1-mo changes in human milk production rate (HMPR), measured with a validated milk expression protocol. Secondary outcomes included changes in perceived insufficient milk (PIM) and lactation self-efficacy scores. RESULTS: Among 176 randomly assigned participants (age: 31.3 ± 5.8 y; 71.0% self-identified as White, 15.3% Hispanic/Latin, 6.3% Black, and 4.0% Asian), 90 participants (51.1%) completed endline HMPR measures and 129 (73.3%) completed secondary outcomes. Imputed models showed a mean increase in HMPR of 5.8 ± 15.7 mL/h in control participants and 5.5 ± 17.6 mL/h in the LC participants after 1 mo of daily intake of the cookie. No significant differences were observed with adjusted linear mixed models on the multiply imputed data comparing baseline-to-endline changes in HMPR, PIM, or breastfeeding self-efficacy: mean (SE) difference-in-differences for HMPR, -0.33 (4.97), P = 0.948; PIM scores (range: 5-50), -0.52 (1.83), P = 0.775; and self-efficacy scores (range: 14-70), 0.31 (2.23), P = 0.888, respectively. CONCLUSIONS: This study found no evidence for the effect of consuming LCs on HMPR, PIM, or breastfeeding self-efficacy in exclusively breastfeeding parents with an overall adequate perceived milk supply. Recommendations to consume LCs for increasing objective or subjective milk supply may deliver false hope and unnecessary financial costs at a vulnerable time. TRIAL REGISTRATION NUMBER: This trial was registered at clinicaltrials.gov as NCT04805008.
