In good news for those prone to winter coughs and colds, research shows consuming flavonoids – found in green tea, apples, blueberries, cocoa, red wine and onions – can significantly reduce the risk of catching a cold.
The research, to be presented at the Dietitians Association of Australia (DAA) National Conference in Perth (13-16 May), shows adults are 33 per cent more protected from the common cold (upper respiratory tract infections - URTI), if they eat foods rich in flavonoids or take flavonoid supplements, compared with those who don't.
Researcher Andrea Braakhuis from the University of Auckland said people who eat flavonoids also have fewer sick days.
'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 Dr Braakhuis.
She said most adults have two to three colds a year, and children can 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 Dr Braakhuis.
Dr Braakhuis said nutrition scientists are learning more about the special components in foods, like flavonoids, which are thought to have anti-viral, anti-inflammatory and antioxidant properties, so can help reduce the incidence of coughs and colds and boost immune function.
At this stage, she said it's too soon to recommend whether foods or supplements are a better source of flavonoids, and what the ideal dose is.
'Eating five serves of veggies and two serves of fruit each day in a variety of colours 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," said Dr Braakhuis.
Commenting on the research, President of DAA, Liz Kellett said: 'Delegates at the DAA National Conference are often privy to early research leads, where diet is shown to have beneficial effects on health. Dietitians are leaders in nutrition, and this is exactly what this research is showing."