Nicotine Dependence

How does your DNA influence your response to nicotine

7 minute read

What is nicotine addiction?

Nicotine addiction is the dependence on the drug nicotine, making it difficult for the user to stop despite the negative ramifications on a users health. Nicotine is highly addictive and most commonly found in tobacco. Smoking creates a quick release of nicotine, with the positive effects of the drug, such as a decrease in anxiety, felt within about 8 seconds of inhalation .

This combination makes nicotine addiction very effective and difficult to quit, and it is one of the leading causes of preventable deaths worldwide .

Symptoms and effects of nicotine addiction?

Nicotine creates a short-term high for the user but results in long-term negative health effects. About half of regular smokers go on to die of a disease caused by tobacco .

This is because smoking causes increased risks of heart disease, stroke, cancer, and diabetes. Smoking is damaging to most organs in the body and is detrimental to the body’s immune system. Nicotine addiction, which is mostly caused by smoking, has wide-spread effects and consequences.

When trying to stop or limit intake, nicotine addiction causes withdrawal symptoms. These can include anxiety, irritability, cravings, a depressed mood, insomnia, and restlessness. These symptoms make it more difficult to stop taking nicotine.

What is the main cause of nicotine addiction?

Nicotine addiction is caused by a mixture of the positive effects of the drug, social pressure and availability of nicotine, and genetic susceptibility to nicotine dependence. Nicotine affects the balance of two chemicals in the brain: dopamine and noradrenaline. These changes to the balance of the chemicals give positive mood and neural effects, which often leads to a drive to experience those feelings again. Nicotine addiction is mainly caused by smoking – either traditional tobacco cigarettes or electronic cigarettes. Other sources of nicotine include patches and chewing tobacco. Recently, an increase in research has emphasised the importance of genetics in nicotine addiction.

Genetics and nicotine addiction

Genetics can influence how the receptors in the brain respond to nicotine, likely by making nicotine receptors more or less responsive, affecting how addictive the drug is for the person. As a result, genetics can influence the likelihood of becoming addicted to nicotine as well as the number of cigarettes smoked per day.

For example, carriers of 'AA' at rs13277254, which is located near a gene that is part of the nicotine receptor, are nearly twice as likely to become dependent on nicotine compared to people with 'GG' at this position .

See which version of rs13277254 you carry:

One of the strongest associations between genetics and smoking behaviour is with the number of cigarettes (or packs of cigarettes) smoked per day. Genetic variants at rs1051730 have been shown repeatedly to contribute about 1 cigarette per day .

See which version of rs1051730 you carry:

Numerous studies have found a link between these genetic variants and lung cancer risk, which appears to be directly related to the number of cigarettes smoked . As a result, while genetics play a role in smoking behaviour, and may make it more challenging to quit, the best advice for reducing risk of lung cancer, and other smoking-associated diseases is to reduce or eliminate smoking whenever possible.

How to relieve nicotine addiction?

The symptoms and negative effects of nicotine addiction can be relieved firstly by quitting smoking. The symptoms of the withdrawal symptoms can be relieved through other ways of delivering nicotine – gum, inhalers, lozenges, and nasal sprays. The effectiveness of these medications improves over the long-term. Support from family and friends also increase the effectiveness of attempts to quit smoking. Quitting smoking can prevent increasing the risk of long-term effects, and withdrawal symptoms often fade quite quickly.

Conclusion

Nicotine addiction affects people across the world and is a major public health issue in many countries. It is caused by a mixture of the addictive qualities of nicotine, social pressures and availability of cigarettes, and our genetic disposition to the effects of nicotine. The long-term effects of nicotine addiction include increased risk of many common diseases including diabetes, heart disease, and lung cancer, so smoking and electronic cigarettes should be avoided or reduced as much as possible.

Image credit: Paweł Czerwiński - Unsplash

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