Updated

Massage therapy may help people who suffer from chronic back pain, although the effects tend to disappear over the longer term, according to a U.S. study.

After 10 weeks, patients who got weekly massage sessions used fewer painkillers and spent less time in bed than those who didn't get any special care, although the positive impact had disappeared after a year, the report in the Annals of Internal Medicine said.

"If we look at patients who seemed to have some substantial improvement, that was about two-thirds in the massage group compared to about one-third among patients getting usual care," said

Richard Deyo of the Oregon Health and Science University, who led the study.

For the study, 401 people were randomly assigned to usual care or one of two kinds of massage therapy, either structural massage or relaxation massage, also known as Swedish massage.

After 10 weeks the massage group had improved considerably compared to the other patients

For instance, about 30 percent of those getting massages had used analgesics in the past week, compared to 40 percent of those getting usual care. Twice as many in the usual care group, or 7 percent, had stayed in bed at least one day in the previous month.

However, some of the apparent benefits of massage had vanished after half a year, and all the gains were gone after a full year.

Deyo said that the results of the latest study compare to what is seen with other kinds of treatment, although the cost-effectiveness is still unclear.

He warned that patients in the study knew which kind of treatment they got, with some perhaps disappointed that they didn't get massages -- which may have affected the results.

In any case, lifestyle changes are often the best treatment.

"Many of us believe that for truly chronic pain problems, exercise programs are actually one of the mainstay treatments that will help people function better on a daily basis," Deyo added.