The nicotine study, conducted by researchers at RTI International, focuses on the DNMT3B gene. The authors state that this gene is most commonly found in people of European and African descent, and its presence increases the likelihood of a person developing an addiction to nicotine.
More than this, the team states, the presence of the DNMT3B gene is also a strong indicator of smokers going on to develop a heavy consumption of tobacco cigarettes and a far higher incidence of developing lung cancer. The findings were produced from studying more than 38,000 individuals from countries including the United States, Finland, the Netherlands, and Iceland.
Lead author, Dana Hancock said: “This new finding widens the scope of how genetic factors are known to influence nicotine dependence. The variant that we identified is common, occurring in 44 percent of Europeans or European Americans and 77 percent of African Americans, and it exerts important effects on gene regulation in human brain, specifically in the cerebellum, which has long been overlooked in the study of addiction.”
The large team of 13 examining the impact of vaping on gene expression hail from Université Laval, a French-language university in Quebec City, Canada. While all research is to be welcomed for its potential to expand our understanding, a caveat needs to be made as the results may not directly translate to humans.
The group studied mice that were exposed for two hours a day, for up to eight weeks, to vapours of propylene glycol and/or glycerol, generated by an electronic cigarette. They discovered that the vapour affected the mice, and the expression level of genes of the circadian molecular clock were altered. These are genes that regulate the body in order to anticipate the environmental changes related to the patterns of day and night.
Putting forward the reasons for the study, they write: “The principal constituents of e‐liquids, namely, propylene glycol and glycerol, are less studied than nicotine and flavouring agents and widely responsible for the perceived safety of electronic cigarette.”
They observed that there was “no apparent sign of lung inflammation”, but “altered expression of circadian molecular clock genes was also observed in the brain, liver, kidney, and skeletal muscle.”
They indicate that this could be serious as: “Glucose metabolism, immune and inflammatory responses, lipolysis, only to name a few, are crucial biological functions affected by the circadian rhythm. Therefore, global deregulation in circadian rhythmicity, even if mild or only at specific times of the day/night could have biological repercussions.”