title: The calming effect of a maternal breast milk odor on the human newborn infant.
abstract: We examined the effects of the odors from mother's milk, other mother's milk and formula milk on pain responses in newborns undergoing routine heelsticks. Forty-eight healthy infants were assigned to four groups, an own mother's breast milk odor group (Own MM), another mother's breast milk odor group (Other MM), a formula milk odor group (Formula M) and a control group. To assess infant distress in response to the heelsticks, their crying, grimacing and motor activities were recorded during the experiment as behavioral indices of the pain response. After the heelstick, the behavioral indices of the Own MM group were lower than those of other groups. By contrast, the Other MM and Formula M groups showed no significant changes compared with the Control group. We also measured salivary cortisol concentration as a biochemical index in Control and Own MM infants before and after heelstick. After the heelstick, the level of salivary cortisol was significantly increased in Control infants, but not in Own MM infants. These results suggest that pain is relieved in human newborns when they are exposed to odors from their mother's milk.
authors.affiliation: Department of Neurobiology and Behavior, Unit of Basic Medical Sciences, Course of Medical and Dental Sciences, Nagasaki University, Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan.
authors.forename: Shota
authors.initials: S
authors.lastname: Nishitani
authors.forename: Tsunetake
authors.initials: T
authors.lastname: Miyamura
authors.forename: Masato
authors.initials: M
authors.lastname: Tagawa
authors.forename: Muneichiro
authors.initials: M
authors.lastname: Sumi
authors.forename: Ryuta
authors.initials: R
authors.lastname: Takase
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Doi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Moriuchi
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Shinohara
mesh_terms: D001007:Anxiety / Q000503:physiopathology / Q000523:psychology; D001942:Breast Feeding / Q000523:psychology*; D003448:Crying / Q000502:physiology / Q000523:psychology; D005149:Facial Expression; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000037:antagonists & inhibitors / Q000378:metabolism; D018730:Infant Behavior / Q000502:physiology / Q000523:psychology; D007231:Infant, Newborn; D008297:Male; D008895:Milk, Human / Q000737:chemistry* / Q000502:physiology; D009034:Mother-Child Relations; D009812:Odorants; D010146:Pain / Q000503:physiopathology / Q000523:psychology*; D010147:Pain Measurement; D012903:Smell / Q000502:physiology*; D013315:Stress, Psychological / Q000503:physiopathology / Q000523:psychology*
chemical_list: D006854:Hydrocortisone