A Colorado State University study that evaluated the effect of storage on antioxidants and anti-cancer properties in colored potatoes shows that while the amount of antioxidant properties increases, the anti-cancer properties of those antioxidant compounds are suppressed.
The research results might also apply to all produce, which shores up the argument for eating local, in-season produce that hasn’t been stored for a long period of time, according to the research team out of the Department of Food Science and Human Nutrition. Some fruits and vegetables are stored for up to 12 months before they appear in grocery stores, according to project researchers.
Potato antioxidants are active against colon cancer. These studies show that purple- and red-fleshed potatoes are higher in these beneficial antioxidants. In fact, the research showed that colored potatoes can deliver antioxidants in levels comparable to blueberries and grapes if they have not been stored for prolonged periods of time.
“If a consumer wants to maximize the health benefits of potatoes, they should shop for locally grown, in-season red- or purple potatoes,” said research project leader Jairam Vanamala. Vanamala is a professor and researcher in the department. The department is part of the College of Applied Human Sciences.
While white potatoes are a rich source of antioxidants, colored potatoes have higher levels of anti-cancer, anti-oxidant and anti-inflammatory compounds. As an example of antioxidant properties in potatoes, one-half of a recently harvested, baked purple potato delivers significant amounts of compounds that fight colon cancer cells. To get the same level of similar compounds in other foods, one would have to eat three and a half recently harvested and baked white potatoes, 600 potato chips, 45 blueberries or 25 grapes.
The research has documented the cancer-fighting antioxidants of plant foods for several years. Vanamala said future studies should explore farm-to-fork operations on the health-benefiting properties of plant foods, with an aim to discover optimal conditions to preserve anticancer properties.
This study was funded by a National Research Initiative Grant from the U.S. Department of Agriculture. The results of this research project were recently published in the Journal of Agriculture and Food Chemistry, an American Chemical Society’s journal. Vanamala’s CSU lab team work on this project included Gaurav Madiwale and Lavanya Reddivari. David Holm, a CSU horticulture professor from San Luis Valley Research Center in Center provided potato cultivars for this study.
Vanamala is also a faculty member in the Cancer Prevention and Control Program, University of Colorado Cancer Center.