Dr Naresh Sen, study author, Consultant Cardiologist at HG SMS Hospital, Jaipur, India, said: "We use music therapy in our hospital and in this study we showed that yoga music has a beneficial impact on heart rate variability before sleeping."
Previous research has shown that music can reduce anxiety in patients with heart disease. However, studies on the effects of music on the heart in patients and healthy individuals have produced inconsistent results, partly they did not state what style of music was used.
The body's heart rate changes as a normal response to being in "fight or flight" or "rest and digest" mode. These states are regulated by the sympathetic and parasympathetic nervous systems, respectively, and together comprise the autonomic nervous system. High heart rate variability shows that the heart is able to adapt to these changes. Conversely, low heart rate variability indicates a less adaptive autonomic nervous system.
Low heart rate variability is associated with a 32-45% higher risk of a first cardiovascular event. Following a cardiovascular event, people with low heart rate variability have a raised risk of subsequent events and death. Failure of the autonomic nervous system to adapt may trigger inflammation, which is linked to cardiovascular disease. Another possibility is that people with low heart rate variability already have subclinical cardiovascular disease.
“Anxiety levels fell significantly after the yoga music, rose significantly post the pop music, and increased after the no music session. Participants felt significantly more positive after the yoga music than they did after the pop music,”
This study investigated the impact of listening to yoga music, which is a type of soothing or meditative music, before bedtime on heart rate variability. The study included 149 healthy people who participated in three sessions on separate nights: (1) yoga music before sleep at night; (2) pop music with steady beats before sleep at night; and (3) no music or silence before sleep at night.
At each session, heart rate variability was measured for five minutes before the music or silence started, for ten minutes during the music/silence, and five minutes after it had stopped. In addition, anxiety levels were assessed before and after each session using the Goldberg Anxiety Scale. The level of positive feeling was subjectively measured after each session using a visual analogue scale.
The average age of participants was 26 years. The researchers found that heart rate variability increased during the yoga music, decreased during the pop music, and did not significantly change during the silence.
Anxiety levels fell significantly after the yoga music, rose significantly post the pop music, and increased after the no music session. Participants felt significantly more positive after the yoga music than they did after the pop music.
Dr Sen noted that holistic therapies such as music cannot replace evidence-based drugs and interventions, and should only be used as an add-on.
He said: "Science may have not always agreed, but Indians have long believed in the power of various therapies other than medicines as a mode of treatment for ailments. This is a small study, and more research is needed on the cardiovascular effects of music interventions offered by a trained music therapist. But listening to soothing music before bedtime is a cheap and easy to implement therapy that cannot cause harm."