Baked purple potatoes suppressed the growth of colon cancer tumors by targeting the cancer's stem cells in both petri dishes and in mice. Colon cancer, the second leading cause of cancer-related deaths in the U.S., is responsible for more than 50,000 deaths every year, according to the American Cancer Society.
Attacking stem cells is an effective method of fighting cancer, according to Jairam K.P. Vanamala, associate professor of food sciences at Penn State and faculty member at the Penn State Hershey Cancer Institute. According to Vanamala, "You might want to compare cancer stem cells to roots of the weeds. You may cut the weed, but as long as the roots are still there, the weeds will keep growing back and, likewise, if the cancer stem cells are still present, the cancer can still grow and spread."
The researchers, who released their findings in the Journal of Nutritional Biochemistry, which was reported in Drug Discovery & Development, used a baked purple potato -- which is widely consumed and baked before consumption -- to make sure the vegetables maintained their anti-cancer properties even after cooking. They found that the baked potato extract “suppressed the spread of colon cancer stem cells while increasing their deaths.” Then they tested the effect of whole baked purple potatoes on mice with colon cancer and discovered similar results. For a human, the equivalent would be two small or one large purple-fleshed potato per day.Researchers believe that 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.
According to Vanamala, "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 butyric acid regulates immune function in the gut, suppresses chronic inflammation and may also help to cause cancer cells to self-destruct. The same color compounds that give potatoes, as well as other fruits and vegetables, a rainbow of vibrant colors may be effective in suppressing cancer growth.”
He added, "When you eat from the rainbow, instead of one compound, you have thousands of compounds, working on different pathways to suppress the growth of cancer stem cells. Because cancer is such a complex disease, a silver bullet approach is just not possible for most cancers."
The researchers are going to test the whole food approach using purple potatoes in humans for disease prevention and treatment strategies. They also plan to test the purple potatoes on other forms of cancer. They believe that purple potatoes could be potentially used in both primary and secondary prevention strategies for cancer. Primary prevention is intended to stop the initial attack of cancer, while secondary prevention is about helping patients who are in remission to remain cancer-free.