WASHINGTON (Reuters) - Turmeric, a yellow spice used widely in Indian cooking, may help stop the spread of cancer, U.S. researchers reported on Thursday.

Tests in mice showed that curcumin, an active compound found in turmeric, helped stop the spread of breast cancer tumor cells to the lungs.
Tests have already started in people, too, said Bharat Aggarwal of the Department of Experimental Therapeutics at the University of Texas M.D. Anderson Cancer Center in Houston, who led the study.
" Here you don't need to worry about safety. The only thing we have to worry about is efficacy," Aggarwal said in a telephone interview.
" Curcumin, as you know, is very much an essential part of the Indian diet," he added.
" What's exciting about this agent is that it seems to have both chemopreventive and therapeutic properties. If we can demonstrate that it is efficacious in humans, it could be of tremendous value, but we're a long way from being able to make any recommendations yet," Aggarwal said.
Earlier research showed that curcumin, which acts as an antioxidant, can help prevent tumors from forming in the laboratory.
For their study, Aggarwal and colleagues injected mice with human breast cancer cells -- a batch of cells grown from a patient whose cancer had spread to the lungs.
The resulting tumors were allowed to grow, and then surgically removed, to simulate a mastectomy, Aggarwal said. Then the mice either got no additional treatment; curcumin alone; the cancer drug paclitaxel, which is sold under the brand name Taxol; or curcumin plus Taxol.
Half the mice in the curcumin-only group and 22 percent of those in the curcumin plus Taxol group had evidence of breast cancer that had spread to the lungs, Aggarwal said in a study to be presented to a breast cancer research meeting in Philadelphia.
But 75 percent of animals that got Taxol alone and 95 percent of those that got no treatment developed lung tumors.
Aggarwal said earlier studies suggest that people who eat diets rich in turmeric have lower rates of breast cancer, prostate cancer, lung cancer and colon cancer.
His team would like to try giving curcumin to women who know they have a high risk of breast cancer -- such as those who have a mother or sister with the disease.
No drug company is likely to develop a natural product that cannot be patented, he said. "There are no companies behind it so our only source of funding is either the National Institutes of Health or the Department of Defense," he said.
This study was funded by the U.S. Department of Defense's Breast Cancer Research Program.