Eating starch could help reduce colorectal cancer risk, according to a recent study.

Researchers found that the consumption of a type of starch that acts like fiber may help reduce colorectal cancer risk associated with a high red meat diet. This is because red meat and resistant starch have opposite effects on the colorectal cancer-promoting microRNAs which promote gene expression.

"This finding supports consumption of resistant starch as a means of reducing the risk associated with a high red meat diet," Karen Humphreys, a research associate at the Flinders Center for Innovation in Cancer at Flinders University in Australia, said in a statement.

Unlike most starches, resistant starch escapes digestion in the stomach and small intestine, and passes through to the colon, or large bowel, where it has similar properties to fiber, Humphreys explained. Resistant starch is readily fermented by gut microbes to produce beneficial molecules called short-chain fatty acids, such as butyrate, she added.

The study involved more than 20 healthy volunteers between the ages of 50 and 75. Participants either ate the red meat diet or the red meat plus butyrated resistant starch diet for four weeks. After a four-week washout period they switched to the other diet for another four weeks.

Researchers found that participants who ate 300 g of lean red meat per day for four weeks has a 30 percent increase in the levels of certain genetic molecules called miR-17-92 in their rectal issue, and an associated increase in cell proliferation. Consuming 40 g of butyrated resistant starch per day along with red meat for four weeks brought miR-17-92 levels down to baseline levels.

"Good examples of natural sources of resistant starch include bananas that are still slightly green, cooked and cooled potatoes [such as potato salad], whole grains, beans, chickpeas, and lentils. Scientists have also been working to modify grains such as maize so they contain higher levels of resistant starch," Humphreys said.

The findings were recently published in Cancer Prevention Research, a journal of the American Association for Cancer Research.