Smokeless tobacco products do not increase the risk of cancer, according to a study that reviewed other studies.

Researchers said in a news release that products used in the past in the U.S. may have increased the risk, but any effect that exists now seems likely to be quite small.

Peter Lee and Jan Hamling carried out the analysis of 89 studies from the U.S. and Scandinavia. They found that, after adjusting for people who also smoked, any effect seems small and much less than the effects of smoking.

In 2005, in U.S. men ages 35 or over, there were a total of 142,205 deaths from seven cancers considered to be caused by smoking, the news release said. If these people had never smoked, the number would drop by more than 100,000, the researchers said.

If smokeless tobacco was introduced to a similar population of never-smokers, any increase in risk would be negligible compared to the lives saved by reducing cigarette use.

Lee also said the study shows that there is not a relationship between oral cancer and smokeless tobacco.

The meta-analysis was published in the open access journal BMC Medicine.