Scientists report that popcorn, which is a 100% unprocessed whole grain, contains more of the highly healthy antioxidant substances called polyphenols than fruits and vegetables, if it isn't dipped in butter, oil or salt.

The hulls of popcorn - the part that everyone hates for its tendency to get caught in the teeth - has been found to have the highest concentration of polyphenols and fibre. The levels of polyphenols rivaled those in nuts and were up to 15 times greater than whole-grain tortilla chips.

Joe Vinson from the University of Scranton in Pennsylvania, who has been a pioneer in analyzing healthful components in chocolate, nuts and other common food items, presented these findings at the American Chemical Society's (ACS) scientific society on Sunday.

Vinson said one serving of popcorn will provide more than 70% of the daily intake of whole grain needed by an adult.

"Popcorn may be the perfect snack food. It is 100% unprocessed whole grain as against all other grains which are actually processed and diluted with other ingredients - meaning only 51% of the weight of the product is whole grain. The average person only gets about half a serving of whole grains a day, and popcorn could fill that gap in a very pleasant way," Vinson added.

Antioxidants are substances that may play a protective role against cancer, heart disease and other diseases. They help combat free radicals produced by the body in response to certain exposures, like cigarette smoke and radiation.

And that piece of popcorn shell that gets stuck in your teeth? It’s called the “hull” and it actually packs the highest concentration of antioxidants and fiber, which may make you think twice the next time you’re tempted to spit it out.

“Popcorn works as a great snack food, but as with many foods … it’s what you do to it that determines its health value,” said Keith Ayoob, a registered dietitian and associate professor at the Albert Einstein College of Medicine.

Oil, butter and salt dilute the health benefits of popcorn by adding fat and even doubling its calories. But if plain popcorn sounds too bland, consider adding spices or herbs to boost its taste.

“Get a little creative,” says Ayoob. Instead of salt, “toss in flavorings like chili powder, cinnamon, curry powder, dried dill … or a teaspoon of grated parmesan cheese.”

Vinson, however, cautioned that the finding should not make people give up fruits and vegetables.

"Popcorn cannot replace fresh fruits and vegetables in a healthy diet. Fruits and vegetables contain vitamins and other nutrients that are critical for good health, but are missing from popcorn," he added.

Vinson explained that the same concentration principle applies to dried fruit, which holds a polyphenol edge over regular fruit.