Aug. 20, 2012 -- Sweet potatoes are already packed with antioxidants and fiber, but zapping them with an electric current can boost these levels by as much as 60%, a new study shows.

The simple experiment doesn’t change the taste of the tuber either, says researcher Kazunori Hironaka, PhD, of the University of the Ryukyus, Nishihara in Okinawa, Japan.

Researchers bathed the sweet potatoes in salty water and then passed various currents through the water and spuds for five minutes. The team had previously tried the experiment on white potatoes with similar results.

Sweet potatoes have high levels of polyphenols -- even before they get zapped. Antioxidants such as polyphenols are thought to help mop up damaging free radicals, which have been linked to cancer and other diseases.