Smell of Vanilla Reduces Breathing Problems
in Premature Infants

January 28, 2005

Babies who are born prematurely often have breathing problems. In fact, approximately 80% of infants born after only 30 weeks of development have episodes of apnea, when they temporarily stop breathing. Doctors often treat these babies with drugs such as caffeine, theophylline and doxapram to prevent apnea. However, these drugs have significant side effects (for example, sleep problems, hyperactivity and gastrointestinal disorders) and do not work in all infants. Researchers at the National Center for Scientific Research (CNRS) in Strasbourg, France, have found that the smell of vanilla can reduce apnea in premature infants who do not respond to drug treatment.

Dr. Luc Marlier and his co-workers at the CNRS tested 14 premature babies in the intensive care unit at the University Hospital in Strasbourg. The respiratory rate of each baby was monitored on three consecutive days:

Day 1 (baseline control): no treatment.

Day 2 (experimental condition): 15 drops of a vanillin solution was applied to the pillow of each infant. (Vanillin smells like vanilla.)

Day 3: (recovery control): no treatment.

The number of apnea episodes occurred significantly less often when the babies were exposed to the vanilla smell. The average number of apnea events was 34.7 on Day 1 (baseline control) and 33.2 on Day 3 (recovery control), but only 22.2 on Day 2 (when vanilla was placed on the pillows). The vanilla smell effectively reduced apnea in 12 of the 14 infants.

The scientists are not certain how the vanilla odor works to prevent apnea, but they offer two hypotheses:

  1. Vanillin has direct or indirect effects on respiratory centers in the brain. Vanillin may reach the brain through the bloodstream after passing through the nasal mucosa or it may be carried into the brain by nerves in the olfactory system.
  2. Vanillin helps infants adapt to stress.

So far, the researchers have tested vanillin only on infants with apnea who do not respond to drug treatment. Pleasant odors other than vanilla have not been tested. Nevertheless, because odor therapy is simple, inexpensive and without side effects, it appears to be a useful treatment for at least some premature infants with apnea.

References and Links:

  1. Marlier, L., Gaugler, C. and Messer, J., Olfactory stimulation prevents apnea in premature newborns, Pediatrics, 115:83-88, 2005.
  2. From Nose to Brain?

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