Compounds found in purple potatoes may help kill colon cancer stem cells and limit the spread of the cancer, according to researchers.
Baked purple-fleshed potatoes suppressed the growth of colon cancer tumors in petri dishes and in mice by targeting the cancer's stem cells. Colon cancer is the second leading cause of cancer-related deaths in the U.S. and responsible for more than 50,000 deaths annually, according to the American Cancer Society.
The researchers, who released their findings in the Journal of Nutritional Biochemistry, used a baked purple potato because potatoes are widely consumed and typically baked before they are consumed, especially in western countries. They wanted to make sure the vegetables maintained their anti-cancer properties even after cooking.
In the initial laboratory study, the researchers found that the baked potato extract suppressed the spread of colon cancer stem cells while increasing their deaths. Researchers then tested the effect of whole baked purple potatoes on mice with colon cancer and found similar results. The portion size for a human would be about the same as eating a medium size purple-fleshed potato for lunch and dinner, or one large purple-fleshed potato per day.
According to the researchers, there may be several substances in purple potatoes that work simultaneously on multiple pathways to help kill the colon cancer stem cells, including anthocyanins and chlorogenic acid, and resistant starch.
"Our earlier work and other research studies suggest that potatoes, including purple potatoes, contain resistant starch, which serves as a food for the gut bacteria, that the bacteria can covert to beneficial short-chain fatty acids such as butyric acid," the researchers said. "The butyric acid regulates immune function in the gut, suppresses chronic inflammation and may also help to cause cancer cells to self-destruct."
The next step would be to test the whole food approach using purple potatoes in humans for disease prevention and treatment strategies. The researchers also plan to test the purple potatoes on other forms of cancer.
Using evidenced-based foods as a proper cancer prevention strategy could complement current and future anti-cancer drug therapies. The researchers believe that foods could actually offer a healthier way to prevent cancer because they often have limited side effects compared to drug treatments.