Monday January 11 2010
Several studies have looked at the potential benefits of Mozart
Playing Mozart to premature babies can help them gain weight, according to The Daily Telegraph. The newspaper said that new research has shown that babies hearing the music used less energy, which might help them gain weight faster.
The study behind this news looked at 20 healthy premature babies and found that exposure to 30 minutes of music composed by Mozart reduced the babies’ resting energy expenditure. However, weight gain itself was not measured, and the researchers themselves are cautious about linking their findings to the weight gain seen in other studies on music. They say that “the clinical implications of our findings belong to the field of speculation”, and that more research is required. This is a sensible bottom line for this early research, and more work needs to be done before Mozart or musical therapy has a place in the routine care of premature babies.
Where did the story come from?
This study was carried out by Dr Ronit Lubetzky, Dror Mandel and colleagues from the Tel Aviv Sourasky Medical Centre, Tel Aviv University, the Shaare Zedek Medical Center and the Hebrew University. There is no indication of whether or not this study received external funding. The authors declare that they have no financial relationships relevant to this article. It was published in the peer-reviewed medical journal Pediatrics.
Both The Daily Telegraph and the Daily Mail cover this research in a balanced way, explaining that the study compared the amount of energy babies used while listening to Mozart to the amount of energy they used when they were at rest. However, the newspaper headlines may lead a reader to think that the study assessed the effects of music on weight gain in babies, but this is not the case. The study assessed the effect of music on short-term metabolic efficiency, and did not measure any changes in weight.
What kind of research was this?
This was a randomised crossover trial investigating the hypothesis that music can reduce the resting energy expenditure in growing healthy preterm infants. This trial looked at how the music of Mozart affected 20 healthy preterm babies of an appropriate weight for their gestational age.
In their discussion, the researchers say that other research has found that Mozart’s music has improved some aspects of intelligence in adults, lowered heart rates, and reduced salivary cortisol (an indicator of stress levels) and distressed behaviour. They say that Mozart’s music has even increased weight gain in premature infants. The potentially beneficial effect of music has been termed ‘the Mozart effect’.
In this study the researchers investigated how music affects metabolic efficiency, which they say might then explain the effects on weight gain seen in other research. Their study design, a randomised crossover trial, is an appropriate way to assess the effects of an intervention such as the influence of music. As this was a crossover study, the babies would have acted as their own controls. This means that each baby would have been subject to both treatments, with the researchers deriving their results by comparing the way any particular child responded to music with their metabolism during no music.
What did the research involve?
The study was conducted at the neonatal intensive care unit at a maternity hospital in Tel Aviv. In total, 20 premature babies were selected to participate. All were healthy in spite of being premature, with no significant complications of prematurity and no congenital problems.
The babies were randomly assigned to experience either exposure to music or no music first, with the alternative treatment being given the next day. During the music exposure phase the children were played music from a ‘Baby Mozart’ CD played through a CD player with mini speakers placed inside the incubators. These were carefully calibrated not to be too loud and not to drown out background noise. Each baby’s use of oxygen and production of carbon dioxide was measured each minute during this 30-minute exposure period. During the music-free assessment phase the children underwent the metabolic measures for 30 minutes.
The researchers note that no other music was heard by the infants during the whole study period, except for the 30 minutes of exposure related to the study. The babies received the same type of food on both study days and were treated the same during their assessments.
What were the basic results?
Of the 20 babies selected 18 were included in the final analysis. One was excluded because of high heart rate and another due to excessive body movements deemed unrelated to music. Resting energy expenditure (REE) was similar between the groups in the 10 minutes before exposure, but during the next 10-minute period, infants who were exposed to music had a significantly lower REE than when they were not exposed to music (p=0.028). This pattern was also seen during the third 10-minute period (p=0.03). The researchers say that, on average, the effect of music is a reduction of 10-13% of REE from the start of the examination phase, and that this effect was obtained within 10 to 30 minutes.
How did the researchers interpret the results?
The researchers conclude that exposure to Mozart’s music significantly lowers REE in healthy preterm infants. They speculate that this ‘effect of music’ might partially explain the improved weight gain that has been attributed to ‘the Mozart effect’ in other research.
This small crossover study has found that exposure to the music of Mozart seems to reduce the expenditure of energy for healthy premature babies at rest. The researchers speculate that this may be the reason behind the findings from another study that music can lead to weight gain in premature infants, but they have not actually measured weight gain in this group of children. Also, comments in the press suggest that the repetitive melodies in Mozart’s music might make it better than Beethoven, Bach or Bartok, but the researchers did not compare Mozart with other composers or other types of music.
Another possible source of error could lie in the fact that this was a crossover trial, which by definition exposes the same individual to both experimental and control conditions. As such, the researchers need to be sure there is enough time between switching to allow the effects of the exposure to wear off. However, the researchers say that music does not appear to have a long-lasting effect, which seems to be supported by the results of this study.
It is difficult to extrapolate the findings of this small study to any application for neonatal care. Important questions remain, for example how long the music therapy should be applied and whether exposure might interfere with aspects such as the babies’ sleep. Also, it is not sufficient to conclude that because music led to a reduction in energy expenditure this means an improvement in metabolism. There are other components to metabolic efficiency that are not captured by this one measure.
The researchers themselves note that “the clinical implications of our findings belong to the field of speculation”, and that it is unclear whether the observed reduced energy expenditure leads to better metabolic efficiency, and in turn enhanced growth rates. More research is needed before this type of experimental music therapy has a place in the routine care of babies in neonatal intensive care units.