Lavender aroma was found to reduce stress and crying and enhance sleep in very young infants, according to a recent study.

In the study “Lavender bath oil reduces stress and crying and enhances sleep in very young infants,” a group of 30 women and their infants were randomly assigned to one of three groups—1) a lavender bath oil group, 2) a nonaroma bath oil group or 3) a lavender bath oil group in which the mothers received an advertisement that the bath oil “helps calm babies when they get irritated” or “helps settle them down before bedtime”—to assess the effects the lavender aroma had on infants’ stress levels, crying and sleep behaviors. The group receiving advertisements was included to determine the additional effects of the mothers’ expectations about the benefits of the bath oil.

The mothers were recruited at a nursery school, and the study took place at the Touch Research Institute’s (TRI) infant lab in Miami, Florida. The infants ranged in age from one-week to four-and-half-months and were 73-percent female and 27-percent male. The mothers averaged 27 years old and were 65-percent Caucasian and 35-percent Hispanic.

In all three groups, each woman was videotaped bathing her infant using either the scented or unscented bath oil. Following the bath, the mothers dried their babies, placed them in a bassinet for sleep and left the room, at which point the infants were videotaped for 20 minutes to monitor sleep behaviors.

To measure stress-reducing properties of the lavender-scented bath oil, saliva samples for cortisol assays were taken from the women and infants in each group immediately before the bath and 20 minutes after the bath (or immediately after the sleep session for infants). Because changes in cortisol have a 20-minute lag time, the saliva samples reflected responses to stimulation occurring immediately following the bath session.

To measure bathing behavior, the videos of the mother-child interaction during the bath sessions coded certain behaviors, including mother relaxed, mother smiling, mother touching and infant looking at mother. To measure sleep behavior, the videos of the infants in the bassinet coded sleeping behaviors, including crying and deep sleep (no body or eye movements).

The bathing and sleep behaviors were coded second-by-second on a laptop computer using a program designed to code sleep-wake behavior, which yielded the percent of time each of the behaviors occurred. Interobserver reliability was determined by the simultaneous coding of one third of the videotapes by two coders, and reliability was calculated by Cohen’s Kappa.

Data collected from the completion of the study regarding bathing behavior showed mothers in group one (lavender oil) and two (nonscented oil) were relaxed a greater percentage of the time than those in group three (lavender oil with advertisement); the mothers in group one tended to smile a greater percentage time than those in group two, while group three did not differ from groups one or two on mother smiling; the mothers in groups one and three touched their babies a greater percentage of the time than the mothers in group two; and the infants in group one looked at their mothers a greater percentage of the time than the infants in groups two or three.

Data collected regarding infants sleeping behaviors showed the infants in group one were in deep sleep a greater percentage of the time than those in group two; the infants in group one tended to spend less time crying post-bath and prior to sleep onset as compared with group two. The group three infants did not differ from group one or two in terms of sleep behavior.

Data collected from the cortisol samples showed cortisol levels decreased for mothers in both aroma groups (one and three), while cortisol levels for the infants decreased in group one and marginally increased for group two. Cortisol levels for infants in group three showed no change.

The authors noted mothers in group three may have experienced “performance anxiety” because the advertisement created an expectation that the lavender bath oil would be calming. The authors further explained that this anxiety may have also affected their infants’ behavior during bath and sleep.

“These data suggest that infants with irritability and sleep problems could be calmed by this aroma and may experience more restful sleep,” say the studies author.

Sources: Touch Research Institute, Miller School of Medicine, University of Miami, Miami, Florida; Fielding Graduate University, Santa Barbara, California; and Duke University School of Medicine, Durham, North Carolina.

Authors: Tiffany Field, Tory Field, Christy Cullen, Shay Largie, Miguel Diego, Saul Schanberg and Cynthia Kuhn. Originally published in Early Human Development (2007), doi: 10.1016/j.earlhumdev.2007.10.008.