The traditional cinema snack contains surprisingly large amounts of healthy antioxidant plant chemicals called polyphenols, scientists have found. Tests showed that the compounds account for 2.5% of popcorn kernels by weight. This is higher levels than were seen in a range of other cereal products.
Polyphenols, also found in fruits, vegetables, chocolate, wine, coffee and tea, are known to protect the heart and reduce the risk of cancer.
US chemist Dr Joe Vinson, who made the discovery, said: "We really were surprised by the levels of polyphenols we found in popcorn. I guess its because it's not processed. You get all the wonderful ingredients of the corn undiluted and protected by the skin. In my opinion it's a good health food."
Dr Vinson's research supports the idea that polyphenols in whole grains, rather than their fibre content, is what makes them healthy.
His team at the University of Scanton in Pennsylvania analysed a range of whole grain breakfast cereals and snacks.
The researchers found the products contained similar levels of antioxidants per gram as fruits and vegetables.
Popcorn was one of the richest sources. In comparison, breakfast cereals had polyphenol levels ranging from 0.03% to 0.5% by weight.
The findings were presented at the American Chemical Society's annual meeting in Washington DC.
The definition of polyphenol is a substance that is found in many plants and gives some flowers, fruits, and vegetables their color. Polyphenols have antioxidant activity.
The most abundant polyphenols are the condensed tannins, found in virtually all families of plants, and comprising up to 50% of the dry weight of leaves. The convergent evolution of tannin-rich plant communities has occurred on nutrient-poor acidic soils throughout the world. Tannins were once believed to function as anti-herbivore defenses, but more and more ecologists now recognize them as important controllers of decomposition and nitrogen cycling processes. As concern grows about global warming, there is great interest to better understand the role of polyphenols as regulators of carbon cycling, particularly in northern boreal forests.