Sugar has a calming effect on babies that lasts beyond 10 minutes, new Toronto research suggests.

Researchers at the Hospital for Sick Children, the University of Toronto, Mount Sinai Hospital and York University studied 240 babies and their reactions after half were given sugar and the other half were given a placebo following a painful medical procedure.

The research involved measuring the "pain responses" of the babies during a diaper change after a blood test, including recording their heart rate and facial reactions, such as squeezing their eyes shut and bulging their brows.

The findings, published Monday in the journal Pediatrics, determined that while babies cried during a diaper change after a blood test, giving them a bit of sugar after the needle appeared to dull the pain.

The majority of the babies in both the group given the sugar and the group given a placebo were given a diaper change within an hour of the blood test.

The infants given table sugar, or sucrose, had lower pain scores than the infants given placebos.

"This study demonstrates than when sucrose is used for pain, it also reduces infant responses to caregiving procedures performed afterward," the study reads.

Dr. Anna Taddio, an adjunct scientist and pharmacist at the Hospital for Sick Children and an associate pharmacy professor at the University of Toronto, said in a news release that the research shows the benefits of sugar extend beyond "the painful event" to "other potentially uncomfortable procedures."

Taddio said the study is the first to determine the effects of sugar on routine care performed after painful procedures.

A previous study by the same research team found that sugar reduces infant responses during painful procedures. That research was published last summer in the Canadian Medical Association Journal.

Sugar was considered to have benefits for procedures that last up to 10 minutes, but until the study published Monday, research had not yet determined its effect beyond the 10- minute mark.

"Based on the results of the study, sucrose may be recommended for caregiving procedures that follow painful events," Taddio said.

Taddio said more studies are needed to determine why sugar can relieve pain and calm infants, and to look at the effectiveness of treating babies with sugar in other situations.