The study from the University of Auckland showed Friday that eating flavonoids, found in green tea, apple, blueberries, cocoa, red wine and onions can significantly reduce the risk of catching colds and coughs.

The study showed adults could be 33 percent more protected against the common cold, or upper respiratory tract infections, if they eat flavonoids or take flavonoid supplements, compared with those who don't.

People who eat flavonoids also took fewer sick days off work, nutrition researcher Andrea Braakhuis said in a statement.

"These findings show that if you're generally healthy, eating flavonoids found in lots of fruits and vegetables can help stave off the bugs over winter," said Braakhuis.

Most adults had two or three colds a year and children could have up to five, with symptoms including a sore throat, cough, runny nose and headache.

"We'd all love to make it through winter without one of these nasty colds. They're a leading cause of visits to a doctor, yet antibiotics don't help, so it's worth giving flavonoids a go as part of a healthy diet," said Braakhuis.

Nutrition scientists were learning more about the special components in foods, like flavonoids, which were thought to have anti-viral, anti-inflammatory and antioxidant properties that help reduce the incidence of coughs and colds and boost immune function.

"Eating five serves of vegetables and two of fruit each day, in a variety of colors, will put you well on the path to getting enough flavonoids. Make sure your dinner plate is at least half full of vegetables, sip green tea over winter and enjoy the occasional red wine," she said.