Given the roles of oxidative stress and chronic inflammation as risk factors for cancer, the antioxidant and anti-inflammatory richness
of vegetables high in anthocyanin compounds, such as those found in purple potatoes, help in the prevention of certain types of cancer, even after cooking, say researchers.
The new data, published in the Journal of Nutritional Biochemistry, tested the potential for anthocyanin-containing purple potatoes to block the growth of cancer tumours, even when they have been cooked -- after previous research suggested that the polyphenols found in purple potatoes (PP) may help to battle cancer.
Anthocyanins are in the class of flavonoids -- compounds found in fruits, vegetables and beverages -- that have aroused interest because of their potential health benefits.
These antioxidant pigments may also reduce blood vessel hardening and improve overall heart health.
Other studies have shown that anthocyanins may help reduce the risk of heart disease and diabetes.
According to a 2009 study: "A growing body of evidence suggests anthocyanins and anthocyanidins may possess analgesic properties in addition to neuroprotective and anti-inflammatory activities".
Led by Venkata Charepalli from Pennsylvania State University, the team used laboratory tests including in vitro cell line investigations and animal modelling to test how PP impacted colon cancer growth, and in particular, colon cancer stem cells (CSCs), which have previously been suggested to be target by dietary bioactives such as curcumin.
"However, there are no laboratory studies investigating the anti-cancer properties of dietary whole foods such as PP on colon CSCs," noted Charepalli and colleagues -- who noted that "the establishment of a link between anthocyanin-containing PP and inhibiting colon CSCs could be very impactful."
The team reported that their data from in vitro and mouse models suggests that baked purple-fleshed potatoes suppressed the growth of colon cancer tumours by targeting the cancer's stem cells.
They added that there may be several substances in purple potatoes that work simultaneously, and 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," said study senior author Professor Jairam Vanamal -- also of Penn State. "The butyric acid regulates immune function in the gut, suppresses chronic inflammation and may also help to cause cancer cells to self-destruct."
Vanamala concluded that purple potatoes could be potentially used in both primary and secondary prevention strategies for cancer -- but warned that because cancer is such a complex disease, a silver bullet approach is just not possible for most cancers.
Mae Chan holds degrees in both physiology and nutritional sciences. She is also blogger and and technology enthusiast with a passion for disseminating information about health.