Teenagers who use e-cigarettes are nearly five times more likely to smoke tobacco later in life, researchers have warned.
Figures suggest more than one in three 15 year-olds have used e-cigarettes despite it being illegal to sell them to under-18s.
The research, led by the University of Bristol, found that using e-cigarettes increased the odds of subsequently smoking tobacco by a factor of 4.6 when compared with those who had never vaped.
More than one in three 15 year-olds have
If under-18s were excluded from the data, the odds of smoking cigarettes was 3.17 times higher among vapers than non-vapers, but if they were included the multiplier rose to 4.87.
However, the researchers said the findings were not definitive and that the link could be explained by the tendency of rebellious teenagers who try e-cigarettes to be more likely to experiment with smoking.
Despite this, they said there was some evidence of a causal link, with all the data going “consistently in the same direction”, the Daily Mail reports.
“There are plausible causal pathways (e.g. nicotine addiction, similar hand-to-mouth actions for both behaviours),” the authors said. “This suggests the results provide some support for a causal relationship between e-cigarette use and later smoking. This is in line with the theory that e-cigarettes act as a gateway to smoking.”