Some electronic cigarette flavours are worse for you than others, according to cancer researchers.

Roswell Park Cancer Institute scientists exposed bronchial cells to chemicals from different e-cigarettes.

They found that out of the six flavours under test - tobacco, pina colada, menthol, coffee and strawberry - strawberry was the worst, in terms of damage to cells.

Lead researcher Maciej Goniewicz of Roswell Park said, ‘Although many of the flavorings used in e-cigarette liquids have been certified as safe for eating, little is known about their effects when heated and inhaled in e-cigarettes.

‘Caution should be used with these products until more comprehensive studies are performed.’

The researchers also confirmed an earlier finding that high-voltage devices are more toxic.

Earlier this year, scientists from the Lawrence Berkeley National Laboratory found that emissions of dangerous chemicals vary widely between gadgets - and even between puffs.

The researchers found that cheaper gadgets with one heating coil release higher levels of irritant chemicals.

Dr Goniewicz said, ‘Our study demonstrates that e-cigarette products differ significantly in the degree of their cellular toxicity to bronchial epithelial cells.

‘These findings have important regulatory implications, because the features of e-cigarette products – such as the power of the device and the presence of flavorings – can be regulated and standardized.

‘Additionally, users may want to reduce their potential harm by choosing products with lower toxicity profile and operating their devices at lower power settings’