We know it makes us feel good. Now science is discovering how singing can treat illnesses from asthma to Parkinson's – and even prevent colds and flu. Tessa Thomas reports

When Robert Wyatt of the Sixties rock group Soft Machine had an accident that broke his back, it ended his career as a drummer. But it relaunched his life as a singer – and that, he believes, helped him to overcome the depression and drink problems he suffered in later years.

"Singing is the best free drug going," says the wheelchair-bound musician, who began 2010 by dedicating Radio 4's Today programme on 1 January to a celebration of amateur choirs and who has just recorded a disc with sax player Gilad Atzmon. "It does what exercise does, and more."

Perhaps that explains the growing appeal of community singing. There are now more choirs in the UK than fish and chip shops, and a spate of television programmes about choral singing – including Last Choir Standing and the two award-winning series by choirmaster Gareth Malone – suggest that, as Wyatt puts it, "singing together is so much more than making a noise with voices." In the future, he says, "someone will figure out how it works its magic in the brain."

Choral singing can measurably improve physical health. In a paper in the new issue of the Journal of Applied Arts & Health, specialists identify half-a-dozen ways in which it can improve our mental health, from improving cognitive function to social confidence.

But what is more surprising is that singing in a choir can have a strong impact on physical health. "Like walking, singing has always been taken for granted – it's just something people have always done," says lead author Professor Stephen Clift. "But just as walking is now prescribed, the benefits of singing for health are slowly being rediscovered by health practitioners."

Just how is apparent when one walks into a "Singing for Breathing" session at the Royal Brompton Hospital. Led by professional singing teacher Victoria Hume, a bunch of patients croon their way through a series of vocal exercises and songs. It gets your fingers clicking, but the catchiness or quality of the sound is not the point. The purpose of these sessions is to improve the patients' breathing.

John Townsend has suffered severe chronic obstructive pulmonary disorder for five years. Doctors had him categorised as a lifelong wheelchair case. "Then someone suggested I did this singing programme that was starting up. I just thought it was silly and I think a lot of the doctors did, too. But I quickly learnt it wasn't silly at all."

Within a few months of starting the twice-weekly sessions, the former smoker in his 70s was not only free of the chest infections he had suffered from or years, but was walking regularly without help and was "breathing more deeply than I could remember".

The housework now takes him a fraction of the time it used to, because breathing more deeply and slowly means he takes in more oxygen, gets rid of more carbon dioxide and therefore has increased stamina. In November, the hospital is introducing singing sessions for children with cystic fibrosis and adults with severe asthma.

Susan Walker uses her inhaler less since she started singing. Her initiation was accidental: she was accompanying her husband Brian, a Parkinson's sufferer, to his "Quivers and Quavers" class run by Hereford Primary Care Trust. "People with Parkinson's lose control of their voice, so I started taking Brian to the group. But then I joined in and now I do every session too." Although these are only fortnightly, the effects on both her husband's and her conditions are remarkable, she says. "He stoops and stutters less, I breathe much more easily and we both have better posture. None of the group are much good at singing, by the way!"

As Townsend carries on with his conventional pulmonary rehabilitation programme alongside the singing, so Walker attends a standard speech therapy programme. Both say that it is the singing that makes the most difference – yet the price of it bears no comparison.

"Speech therapy is much more expensive because it's all one-to-one, whereas the singing is in a group – and we're even looking at doing online sessions which will be even more cost-effective," explains Hereford nurse Caroline Evans.

Respiratory consultant Dr Nicholas Hopkinson at the Royal Brompton is a little more guarded, saying that a decreased dependency on medicine and therefore reduced costs "may well" come out in the final analysis after the pilot programme ends in November. "But what is clear is that patients are breathing more slowly and breathing from their diaphragms rather than upper chest, both of which are very beneficial in conditions like emphysema and pulmonary fibrosis."

That such overwhelmingly positive results could transpire for such different conditions doesn't particularly surprise Malone. "Singing is about little flaps of tissue vibrating but it engages so many of the body's systems – the lungs, the heart, the nervous system – that it's not really surprising it has such overall benefits. After a big choral piece you can feel like you have been on a short jog."

A recent study at the University of Stockholm showed that men and women got an oxytocin high when they sang. Oxytocin is not only the hormone of childbirth and lactation: it is also produced during sex. No wonder so many choristers describe sensations of "well-being" to curious researchers.

Meanwhile, a Sidney de Haan research review highlights the way that singing is not only found to enhance energy and mood – even to create a state of "transcendence" – but to boost immunity en route. Samples of saliva taken from singers by Frankfurt University researchers after rehearsals of Mozart's Requiem showed increased secretion of antibodies.

Professor Graham Welch, the professor of music education at the Institute of Education and spokesperson for the national singing programme for schoolchildren Sing Up, offers this as a final solo: "Singing not only improves the body's cardiovascular system, it also reduces the opportunity for bacteria to flourish in the upper respiratory tract, so can help prevent colds and flu."

So more singing on the curriculum this winter could mean more ticks in the register.