Decades ago, the maker of M&M's took its red candies off the market after the dye was linked to cancer.

But red M&M's have been back for some time and scientists are now saying that some food dyes, including Blue No. 2 and Red No. 40, used by candy makers (including M&M), may actually fight cancer, OregonLive.com is reporting.

Scientists from Oregon State University looked at dyes because they are chemically similar to compounds that bind to cancer-causing chemicals, according to the report.

After feeding rainbow trout aflatoxin, a poison linked to liver cancer and made by mold that grows on tree nuts, peanuts and corn, researchers then fed the dyes to some of the trout. The dye-eating trout ended up with fewer liver tumors. Red No. 40 also seemed to fight a dibenzopyrene, a carcinogen in cigarette smoke, the report said.

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OSU professor Gayle Orner told OregonLive.com that the harmful effects of aflatoxin, though not a huge problem in the U.S., could be minimized by mixing the toxin-fighting dye with peanut butter. The dye could be added to corn chips too, the report said. The researchers are now studying the dyes on animals.

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