A team from Virginia Tech has been carrying out a series of studies investigating the carcinogenic (cancer-causing) properties of nicotine. In their latest paper, they report that, in addition to previously acknowledged qualities such as its addictiveness, nicotine is a carcinogenic substance.
MedLine Plus lists the following as effects that nicotine has on the body:
- Decreases appetite
- Boosts mood
- Increases intestinal activity
- Creates more saliva and phlegm
- Increases heart rate
- Increases blood pressure
- May cause sweating, nausea and diarrhea
- Stimulates memory and alertness.
Nicotine is just one of over 4,000 chemicals that can be found in tobacco, and 19 of these other chemicals in tobacco are known to be carcinogenic. Due to the addictive nature of both nicotine and tobacco, it is very difficult to quit using tobacco products once it has become a regular habit.
The American Cancer Society (ACS) report that about half of all Americans who maintain a smoking habit will die as a result of it. Around 480,000 people in the US die every year due to illnesses related to tobacco use - more than alcohol, car accidents, suicide, AIDS, homicide and illegal drugs combined.
Nicotine replacement therapy is a popular method of trying to give up smoking. It involves using products such as skin patches, gum, lozenges and e-cigarettes, which all contain small amounts of nicotine without any of the toxins that are present in cigarette smoke. These products aim to ease the user away from smoking by relieving cravings and making their withdrawal symptoms less severe.
Further dangers of nicotine investigated
The addictive properties of nicotine are often the focus whenever the dangers of smoking are discussed. However, new research from the Virginia Bioinformatics Institute published in the journal Oncotarget has focused on altogether more dangerous properties of the substance, examining its effects on genes.
The authors state that nicotine is not yet considered to be a carcinogen and, as a result, is increasingly being used as a therapeutic. They also reference a recent move from the Food and Drug Administration (FDA) to relax restrictions on many nicotine products, potentially signalling to consumers that the consumption of nicotine products is safe.
The study, led by geneticist Jasmin Bavarva, exposed cells to nicotine and compared them to cells that had not been exposed. They found that thousands more mutations were present in the cells that had been exposed to nicotine compared with the control cells.
The patterns of mutation found were similar to those observed in cells experiencing oxidative stress, a known precursor to cancer. The authors conclude that nicotine exposure can adversely affect genes by inducing mutations, and over the period of significant exposure may contribute to increased cancer incidence.
Prof. Harold Garner, director of the Virginia Bioinformatics Institute's Medical Informatics and Systems Division, says that the results are important:
"For the first time they directly measure large numbers of genetic variations caused only by nicotine, showing that nicotine alone can mutate the genome and initiate a cancer state. This is particularly timely since nicotine is used as a smoking cessation therapeutic."
The team will now aim to understand the effects of long-term nicotine exposure through further research.
Considering the carcinogenic risk that nicotine poses, it may be worth smokers reconsidering the methods that they use to try and quit smoking. Recently, Medical News Today reported on a study that examined how effective e-cigarettes were at helping smokers quit. It yielded the following figures:
- 20% of participants trying to quit by using e-cigarettes were successful
- 10.1% of participants trying to quit by using other nicotine replacement therapies were successful
- 15.4% of participants trying to quit without assistance were successful.
Although e-cigarettes were the most successful method of achieving smoking cessation, these results suggest that avoiding nicotine replacement therapies altogether would not automatically decrease the likelihood of quitting. In fact, avoiding products such as skin patches and gum might even increase the likelihood.
Written by James McIntosh