Flavoured milk contains a caffeine 'bomb'

Some milk drinks contain up to three times the caffeine hit found in a regular cup of coffee, new research shows.

The findings are a wake-up call to parents who buy flavoured milk, believing the drinks are healthy.

The National Health and Medical Research Council warns against giving caffeine to children because it can cause disturbed sleep patterns, bed-wetting and anxiety.

Researchers at Griffith University tested more than 20 varieties of iced coffee-flavoured milk to discover the high caffeine content.

"A lot of people think it is better for you because it is milk-based," Griffith University researcher Ben Desbrow said. "But actually it is worse."

Mr Desbrow's team tested 20 iced coffee products three times over a month, to allow for changes in the product run.

"After calculating an average we found several that had very high levels of caffeine per 100ml. But the issue is these products are sold in 500ml, 600ml or 750ml containers.

"So if there is 35mg per 100ml, you could be getting more than 175mg of caffeine in a 500ml drink and more than 260mg of caffeine in a 750ml drink."

A 250ml can of Red Bull contains 80mg of caffeine.

"Caffeine in iced coffee is considered a natural ingredient so manufacturers are not required to disclose the level of caffeine on the label," Mr Desbrow said. "The product only needs to state that it contains caffeine."

"Manufacturers only need to say how much caffeine is contained in a product when it is added."

Mr Desbrow said consumers, and especially parents, needed to be aware "because children could be consuming more than your average adult".

Caffeine affects the brain by dampening neuro transmitters that would normally make you sleepy, temporarily improving cognitive function and even athletic performance.

The typical consumer drinks about 200mg to 300mg a day in two to three cups of coffee.

Tanya Geary, 28, of Aspley in Brisbane, said she would never give her two boys caffeine because "they would be bouncing off the walls".

"But it is quite alarming to think there is that much in flavoured milk," she said.