This post was originally published on Smartplanet.com
In the last decade, researchers have shown that the part of hops that isn’t used for making beer contains healthful antioxidants and could be used to battle cavities and gum disease. In particular, those antioxidant polyphenols are contained in hop leaves, called bracts. Now, Japanese researchers say they’ve identified some of the substances that could be responsible for these healthful effects.
A little history lesson, via Popular Science. When England began exporting to the colonies in the 18th century, a lot of beer was spoiled by bacteria during the lengthy voyage. But those that had a higher proportion of hops in the recipe appeared to survive without significant product loss. In 1937, microbiologists discovered the antiseptic properties of hops: When exposed to hop extract, bacteria couldn’t survive. Over the next several decades, various teams of researchers show that extracts from bracts stop the bacteria responsible for inflammation leading to gum disease from being able to stick to surfaces -- thus preventing the release of bacterial toxins. In addition to prevention, bracts also removed plaque from teeth.
The most compelling evidence yet came just this month. To get a complete picture of the polyphenolic compounds in hop bracts, a team led by Yoshihisa Tanaka from the research laboratories of Asahi Group Holdings, Japan, used chromatography to separate out various components in 25 grams of hop bract extract.
They found three new compounds, one already-known compound that was identified for the first time in plants, and 20 already-known compounds that were found for the first time in hops. The bracts also contained substantial amounts of proanthocyanidins, which are healthful antioxidants.
Farmers in the U.S. harvest about 2,300 tons of hops (Humulus lupulus L.) a year. But since bracts aren’t used for making beer, no one cares about them and they’re simply discarded. That’s a lot of bracts that could potentially be repurposed. The work may lead to a variety of natural oral products, ranging from effective gum disease prevention to a greener alternative to toothpaste using brewery throwaways. So, drink to your (dental) health this St. Patrick’s Day!
The work was published in American Chemical Society's Journal of Agricultural and Food Chemistry.