Shoppers at Jurong Point were yesterday treated to a lunchtime performance of rousing Chinese New Year songs - by participants of a dementia study.

To determine if singing in a choir can prevent dementia, researchers from the National University of Singapore (NUS) have recruited 93 senior citizens living in Jurong and put half of them in a choir.

While half of them practise singing, the other half, the control group, have been going for a health education programme to manage diabetes, diet and exercise - all factors linked with dementia.

Both groups spend an hour on their programmes and are given lunch once a week, in the study that started in October last year.

Researchers aim to study, over two years, 300 people aged above 60 and at high risk of dementia, and are recruiting more people.

"We're trying to test the efficacy of choral singing more scientifically, to see if it can slow down the development of dementia in those with high risk, and promote the mental health of the elderly," said Dr Feng Lei, the study's principal investigator and a research assistant professor at the NUS Yong Loo Lin School of Medicine.

Singing in a choir may delay dementia as singers work their memory when they learn new songs. They also learn to be mindful, to blend their voices with those of others.

Dementia affects one in 10 Singaporeans aged over 60. There were about 40,000 dementia patients here as at last year and this is projected to reach 53,000 by 2020, and 187,000 by 2050.

For the study, participants are assessed at the start of the study, as well as at 12 months and 24 months.

They go through a blood test to see if their immune systems have improved, and a urine test that looks at oxidation - an indication of brain cell degeneration. They are also tested on things like their memory, concentration and spatial awareness.

Results from both groups will be compared to see which approach is more effective in slowing cognitive decline.

The idea came from Dr Maurine Tsakok, a member of the NUS Society Choir and a consultant obstetrician and gynaecologist in private practice. A decade ago, she had an episode of amnesia at age 66 - she could not recall an eight-hour block, during which she had played golf and even boarded a flight.

"I was like a zombie," she said.

She was diagnosed with global amnesia, a temporary but almost total disruption of short-term memory, and it frightened her, even though doctors said it was benign.

She found anecdotal studies about how choral singing helps with dementia. "But none talked about prevention, which is what I'm concerned about," she said.

She signed up with the NUS Society Choir in 2009 to improve her own mental function. When the choir was looking to sing for a cause, she directed them to the study.

Researchers have raised $400,000 for the MRI scans of the participants, and buses to take them from Jurong Point to NUS, where they rehearse with trainers from the Yong Siew Toh Conservatory of Music. Researchers are now applying for a $1.2 million grant from the Health Ministry.

The clinical trial is part of the 10-year longitudinal Jurong Ageing Study, which aims to reduce depression and dementia in elderly residents of Jurong.

Professor Kua Ee Heok of the NUS Yong Loo Lin School of Medicine, who helms the Jurong Ageing Study, said they observed a side benefit of this study: The elderly start interacting socially.

"Most of them live alone and there's a sense of loneliness. So coming together, singing together, builds up a sense of caring and compassion and builds up social connectedness," he said.

If choral singing proves useful against dementia, choirs for the elderly can be easily replicated across Singapore, he added.

Participant Lee Yum Lum, 79, formerly an office manager, said he enjoys the singing, the regular outings to NUS and the social factor.

"When we meet, we talk about current affairs and family matters. I enjoy singing the songs with people who are also senior citizens."

Correction Note: An earlier version of this story stated that the name of the study's principal investigator is Dr Feng Li. It has now been corrected.