For people who love potatoes, why not venture beyond the typical Idaho Russets or the Yukon Golds, and go for purple instead? What if you could be rewarded with lower colon cancer risks? Indeed, a new research finds that purple potatoes are rich in compounds that stop cancer-promoting proteins in the colon, and could lower the risk of colon cancer overall.
"What we are learning is that food is a double-edge sword - it may promote disease, but it may also help prevent chronic diseases, like colon cancer," said Dr. Jairam Vanamala, a professor at the Pennsylvania State University, and the study’s senior author. "What we don't know is, 'how does this food work on the molecular level?' This study is a step in that direction."
The research team began by focusing on the effects of a high calorie diet (HCD). Previous studies have shown convincing links between HCD and colon cancer, but the exact mechanism are yet to be fully understood.
In experiments, Vanamala’s team noticed that test pigs on a high calorie diet had higher levels of a protein called interleukin-6 (IL-6) in their colon. This protein is considered a pro-inflammatory player, and its activity has been linked to colon cancer development.
The team then looked for plant-based compounds that can counter the cancer-promoting effects of Il-6. And they landed on the purple potato.
“Color-fleshed potatoes contain a variety of secondary metabolites, including polyphenols. Purple-fleshed potatoes are rich in phenolic acids and anthocyanins," the researchers noted. Anthocyanins have anti-inflammatory properties and have been linked to reducing a variety of cancers, including colon cancer. "[...] white potatoes may have helpful compounds, but the purple potatoes have much greater concentrations of these anti-inflammatory, antioxidant compounds."
For 13 weeks, the team fed pigs in three different diet regimens: one group received a standard diet, one group received a high calorie diet, and one group received the high calorie diet supplemented with purple potatoes.
They found that pigs on the high calorie diet had higher levels of the cancer-promoting protein Il-6, as expected. But pigs that received the high calorie diet with purple potatoes had a reduced level of Il-6 that was six times less than the control group.
“We observed that dietary supplementation of purple-fleshed potatoes, even after processing, prevented HCD-induced inflammation. Ultimately, this work is important as [a] chronic inflammatory environment can lead to a multitude of diseases, including type 2 diabetes and colon cancer,” the team wrote.
The conclusion may also apply to other colorful fruits and vegetables, as these are typically high in anti-inflammatory compounds. "The prevalence of chronic inflammation-promoted diseases are on the rise around the globe," the team adds, "thus, it is critical to develop safe, effective, and affordable dietary interventions or strategies to help prevent the onset of diseases."
Additional sources: MNT