Eating cold potatoes helps counter red meat's cancerous effects
potato-salad
Image: Add some cold potato salad to your next steak meal for a protective dose of resistant starch. Credit: eugena-klykova/Shutterstock

If you’re eating more than a steak and a half per week, you’re putting yourself at a higher risk of developing bowel cancer. But a team of researchers from Flinders University in Adelaide, South Australia has found that if you add some ‘resistant starch’ to your meal - a type of starch that doesn’t get digested - it can have a protective effect. Found in bananas, whole grains, beans, and cooked potato that’s been left to cool, resistant starch appears to actively hamper the genetic changes in the gut that can lead to cancer growth.

According to Anna Williams at New Scientist, the team instructed 23 healthy volunteers to eat a diet high in red meat for four weeks. After a month of eating 300 grams of lean red meat every day, the volunteers had cell samples extracted from their guts. Examining these samples, the researchers found a significant increase in their levels of microRNA molecules - a type of genetic material known to promote cancer growth. 

"These elevated microRNAs are associated with the survival and growth of colorectal cancer cells, and with poorer outcomes for people with that type of cancer,” Williams reports.

The team then told the volunteers to repeat the red meat-heavy diet for another four weeks, but this time got them to include resistant starch in their meals either in the form of bananas, cold potatoes, or a special drink.

After a month, their gut cells revealed that their levels of microRNAs had, on average, gone back to their healthy, regular level, as if they hadn’t just spent a month gorging on red meat. "This finding supports the consumption of resistant starch as a means of reducing the risks associated with a high red meat diet,” said lead researcher and gastroenterology expert, Karen Humphreys, in a press release.

But there’s still much more to this story than we know yet, adds Humphreys, telling Williams at New Scientist, "Red meat is likely to be having other cellular effects aside from changing microRNA levels, such as damage to DNA."

The team has published the results of the study in the journal Cancer Prevention Research, and is now looking into if resistant starch is having any other effects on the body related to red meat consumption.