The effects of smoking cigarettes on the body

We all know that smoking is bad for you, but you may not realise just how many negative effects smoking can cause. From premature aging to deadly diseases, smoking can affect nearly every system in your body in some way, from your heart to your skin.

Respiratory system
With every cigarette you are breathing in toxic substances that cause damage to your lungs.

A persistent cough, often referred to as a ‘smoker’s cough’, is a common side effect of smoking. A recent study from the University of Catania describes how cigarette smoke contains a number of substances that are toxic to the hair-like structures in the lungs, called cilia, and can lead to increased mucus production. The damaged cilia cannot move the excess mucus as effectively, causing a persistent cough as the body tries to clear the lungs.

The purpose of the mucus is to trap harmful viral and bacterial pathogens which could cause infection and move them out of the body. When this mucus cannot be cleared these pathogens remain, making smokers more likely to develop respiratory infections. You can read more about this study in our post ‘Switching to vaping restores lungs defence against infection.’

Long-term damage to the lungs can develop into chronic obstructive pulmonary disease (COPD). According to Asthma + Lung UK , COPD describes a group of lung conditions such as chronic bronchitis and emphysema, which cause breathing difficulties due to narrowing of the airways. These diseases make it harder for the lungs to take in oxygen and get rid of carbon dioxide, resulting in breathlessness, coughing, and wheezing.

Tobacco smoke contains a number of known carcinogens; these are substances that damage the DNA in your cells, which can lead to the formation of cancerous tumours. Information from the NHS reveals that smoking is the cause of 70% of all cases of lung cancer and can cause cancer in many other parts of the body, such as the mouth, bowel, stomach, and pancreas.

Recent research has also found that smokers are up to 80% more likely to be hospitalised with COVID-19, and are more likely to die from the disease. During the first lockdown a paper was released suggesting that smoking could protect against the virus, however it has since been retracted and labelled as incorrect and misleading. The new study from Imperial College London has identified that smoking impairs lung function, making smokers more vulnerable to respiratory infections like coronaviruses.

New study finds that lungs heal after quitting smoking
A new study from the Wellcome Sanger Institute and University College London has found that even after long-term heavy smoking, healthy new lung cells can grow once a smoker quits, replenishing the lining of their airways and dramatically cutting the risk of cancer.

Awakening dormant cells
The study has found that dormant cells within the lining of the airway that were not damaged by smoking can awaken once a smoker quits and multiply to replace the damaged cells. This process means that ex-smokers, no matter how long they had been smoking for, were found to have more ‘genetically healthy’ lung cells than current smokers.

29% improvement in overall lung cancer survival rates
Dr Caini, of the Institute for Cancer Research, Prevention and Clinical Network in Florence, and his team have reviewed and summarised the current scientific evidence on whether quitting smoking at or around the time of diagnosis has a beneficial effect on the overall survival of lung cancer patients.

The study, which was published in the Journal of Thoracic Oncology, has found that patients with lung cancer who quit smoking around the time of receiving their diagnosis have a 29% improvement in their chance of survival compared to those who continue to smoke.

Tobacco smoke promotes tumour growth, progression, and dissemination, and can also decrease the efficacy of and tolerance to radiation and systemic therapy. Not only this but it can also increase the risk of complications post-surgery and of developing a second primary cancer.

Cardiovascular system
Smoking is extremely harmful to your cardiovascular system, from an immediate increase in heart rate and blood pressure, to long-term damage which can lead to a number of life-threatening diseases.

According to the British Heart Foundation, smoking can lead to an increase in blood clots, and ‘make the walls of your arteries sticky. This causes fatty material to stick to the walls. The fatty material can begin to clog your arteries and reduce the space for blood to flow properly.’

This build-up of fatty material is one of the main causes of cardiovascular disease, and a blockage in a major artery can have serious implications such as a heart attack or stroke.

The Heart Research Institute UK advises that ‘the risk of heart attack is up to four times greater and the risk of stroke up to two times greater for smokers.’

Cognitive Function
A recent study was conducted to investigate the link between cognitive decline in middle age and smoking. The study found that smoking does appear to increase the risk, but also that quitting smoking can help people to avoid these issues in the future.

Smokers twice as likely to experience memory loss
The research, published in the Journal of Alzheimer’s Disease, was based on a survey of nearly 140,000 people over the age of 45. The self-assessment related to their smoking habits and whether they feel they are experiencing any cognitive issues such as memory loss or confusion.

The data showed that 8% of participants who had never smoked were experiencing such issues, while a concerning 16% of current smokers were.

The Ohio State University (OSU) researchers found that almost 10% of participants aged 45 to 49 reported cognitive issues when surveyed, an age that is considered young to experience such issues. They also noted that almost all of the people in this group were smokers.

These kinds of cognitive issues are rarely seen in people in their 40s and 50s, as in most cases the brain does not start to lose function until after the age of 65.

Smoking has long been identified as linked to an increased risk of cognitive conditions like Alzheimer’s, but to see such a high percentage of cognitive issues in middle-aged people is alarming, and overall smokers were twice as likely to experience these problems than their non-smoking peers.

Quitting can benefit cognitive health
An interesting observation came when looking at the statistics for those who had quit smoking. 12% of participants who had quit over ten years before, and 13% of those who had quit within the last ten years, reported cognitive problems. This suggests that quitting smoking can help stave off future issues like memory loss in your 40s and 50s.

Dr Jeffrey Wing, senior author and epidemiology professor at OSU said:
“The association we saw was most significant in the 45-59 age group, suggesting that quitting at that stage of life may have a benefit for cognitive health.”

Jenna Rajczyk, doctoral student and lead researcher for the study, elaborated:

'These findings could imply that the time since smoking cessation does matter, and may be linked to cognitive outcomes.'

The implication being that the sooner you quit smoking, the less likely you are to experience cognitive decline in middle age, which is seen to be an early indicator of later cognitive problems like Alzheimer’s and dementia.
Quitting smoking for the sake of your health is one of the most common reasons for people making a quit attempt. However, this is often due to a health scare or to lessen the likelihood of future illness like cancer and lung disease, and we do not always think about the implications that smoking could have on our brain and mental function. This research sheds light on how smoking can affect every part of your body, but early action can really make a difference later in life.

Reproductive system
People often talk about the many diseases smoking causes, but you may not be aware that it can also have an impact on fertility in both men and women.

A review from Action on Smoking and Health (ASH) reports that ‘research has established beyond doubt that smoking can have a negative impact on female fertility’ and that it takes longer for a woman who smokes to conceive than a non-smoker. It has also been found that smoking can lead to early menopause, with menopause occurring up to two years earlier in women who smoke.

In men, smoking has been linked to erectile dysfunction, impotence, and a reduced sperm count. ASH report that ‘even light smoking is associated with reduced male fertility.’

According to Cancer Research UK, cigarette smoke contains at least 70 chemicals known to cause cancer, and is a known cause of both cervical and ovarian cancer. Smoking also increases your risk of developing cancer in many other parts of the body, such as your liver, stomach, kidneys, pancreas, bowel, bladder, and can even cause some types of leukaemia.

Eyes, mouth and skin
It is no secret that smoking can leave behind tell-tale signs like yellow fingers and teeth, and the persistent smell of smoke that lingers in your clothes and hair. But it can also have more lasting effects on your face, mouth, and eyes.

Many smokers will be aware that smoking can dull your sense of taste and smell, but these are not the only two senses that smoking can influence.

Information from the Royal Free Hospital London reveals that smokers are twice as likely to lose their eyesight compared to non-smokers. Smoking can cause a number of eye problems, including making you more likely to develop cataracts and macular degeneration, both of which can result in blindness.

Smoking can also take a toll on your oral health, causing issues like mouth sores, ulcers, and gum disease. Information from the Queen Victoria Hospital reports that ‘smoking tobacco causes a lack of oxygen in your bloodstream, leading to infected gums not being able to heal. Smoking causes gum disease to progress faster than in non-smokers. Gum disease is the most common cause of tooth loss in adults.’

According to a review from ASH, smoking can cause the skin to age prematurely, losing its elasticity and taking on a greyish tone. This causes an increase in wrinkles around the mouth and eyes, with one study from the American Council on Science and Health describing how ‘smokers in their 40s often have as many facial wrinkles as non-smokers in their 60s.’

The American Cancer Society identify being a smoker as putting you at higher risk of developing squamous cell carcinoma (SCC), a type of skin cancer, especially around your lips. SCC is the second most common form of skin cancer, and can cause scaly, red patches of skin, open sores or warts to form on the skin. Smoking also increases your risk of developing mouth, throat, larynx, and oesophagus cancer.

What are the benefits of quitting smoking?
The benefits of quitting smoking can be seen as quickly as 20 minutes after your last cigarette, when your heart rate and blood pressure will start to return to normal. Remaining smoke-free will help your body recover from the exposure to harmful substances and can even reverse some of the damage smoking has done to your body.

Many people find they have more energy and a better mood after quitting smoking, and breathing becomes easier, letting you become more active.

According to information from the NHS, after a year of not smoking your risk of heart attack has halved, your lung function has increased by up to 10% and your circulation has improved. Quitting smoking also improves fertility in both men and women and can boost your sex drive. Learn more about the benefits of quitting smoking in our post ‘Stop for good, not just October’.

It is never too late to quit smoking
Quitting smoking is never an easy task, but research has found that even after a cancer diagnosis, smokers can still improve their chances of recovery by kicking the habit. The benefits of quitting can be seen almost straight away, and continue to increase the longer you stay smoke-free.

There are now more resources for stop smoking support than ever, and smoking cessation aids like e-cigarettes are proven to be both effective and less harmful than smoking, while still keeping nicotine cravings at bay.