People receiving chemotherapy often ask about what they can do about the nausea. (J. Scott Applewhite/AP Photo/)

Ginger capsules can help ease nausea from chemotherapy, according to the largest study of its kind of the folk remedy.

About 70 per cent of people with cancer who receive chemotherapy complain of nausea and vomiting, the researchers said.

While there are drugs to effectively control vomiting, nausea is often worse because it lingers, said the study lead's author, Julie Ryan of the University of Rochester in New York.

In a placebo-controlled, double-blind study of 644 cancer patients, those who took lower doses of ginger supplements showed a 40 per reduction in nausea levels compared with those who took dummy capsules.

"We were slightly beside ourselves," said Ryan, who will present the findings at the American Society of Clinical Oncology's annual meeting in Orlando, Fla., on May 30.

People with cancer may cut their treatments short or refuse chemo because of the nausea, according to the society.

While ginger has long been touted for morning sickness and motion sickness, studies have shown mixed results.

Pre-empting nausea

The latest trial suggested timing may be key.

Unlike earlier studies in which patients waited until their treatment day to start taking ginger, in this experiment participants started taking the capsules three days beforehand.

"It was just a different way of thinking to treat nausea, to try and pre-empt it," Ryan said.

About two-thirds of the study participants had breast cancer and the rest had other forms of the disease.

Participants were given one of three doses of ginger extract (0.5, 1 and 1.5 grams) or dummy capsules along with standard anti-vomiting drugs. They rated their nausea levels on a seven-point scale at various times of day during chemotherapy treatment and three days after.

No side-effects reported

Those receiving 0.5 gram or 1 gram of ginger showed the best results, with no side-effects reported.

It could be that earlier absorption of ginger into the body may have anti-inflammatory effects, Ryan proposed.

The researchers used capsules containing concentrated, purified ginger extract. It is not known whether ginger teas or powdered ginger spice could also help, since they were not tested.

The American Cancer Society warns people should talk to their doctor before trying ginger because it can interfere with blood clotting during cancer treatment or surgery.

The U.S. National Cancer Institute paid for the study. The researchers had no ties to the manufacturer of the ginger capsules, Aphios Corp.

With files from The Associated Press