World No Tobacco Day 2024: 7 ways tobacco weakens immunity, increases cancer risk 

Tobacco contains 70 chemicals that are known as “carcinogens” which are known to initiate or promote cancer in the body (Image: Canva)

Persistent coughs, mouth sores, abdominal swelling, or unrelenting fatigue may serve as silent indicators of a deeper struggle within. These are just a few of the many symptoms revealing smoking's impact on the body, signaling the looming threat of cancer.

The smoke from tobacco contains more than 70 cancer-causing chemicals. When you smoke, these harmful substances enter your bloodstream, damaging your DNA and leading to abnormal cell growth.

Tobacco consumption significantly increases the risk of developing various types of cancer, with smokers having a 15 to 30 times higher risk of lung cancer compared to non-smokers, says Dr Vicky Makker, MD, Gynaecological Oncologist, Memorial Sloan Kettering Cancer Center. She adds, “Moreover, tobacco use is linked to cancers of the mouth, throat, esophagus, pancreas, bladder, and cervix. Understanding the mechanisms through which tobacco contributes to cancer is crucial for developing effective prevention strategies.”

Dr Makker shares the various ways tobacco increases the risk of developing cancer.:

Toxic substances: Tobacco contains 70 chemicals that are known as “carcinogens” which are known to initiate or promote cancer in the body. Carcinogens in tobacco are excreted in urine, causing genetic changes in the cells of the bladder and increasing the risk of bladder cancer.

Genetic damage: Tobacco smoke causes direct damage to DNA within cells. This damage can result in mutations, which are changes in the DNA sequence of a cell. These mutations can cause a cell to grow uncontrollably, leading to the formation of a cancerous tumor.

Inflammation and oxidative stress: Inflammation and oxidative stress from tobacco can damage proteins, fats, and DNA. This disruption can cause chronic inflammation and an imbalance in the body's antioxidant defenses.

Weakening immune system: Smoking tobacco leads to the suppression of the immune system, making it less effective at identifying and destroying cancerous cells. This immunosuppression allows cancer cells to proliferate unchecked.

Increase in cell proliferation: Tobacco's harmful compounds, like nicotine, boost cell growth. This condition encourages mutations. The increase in cellular proliferation enhances the likelihood of genetic errors that can lead to cancer.

Disturbance in angiogenesis: Components of tobacco smoke can disturb the process of angiogenesis, the formation of new blood vessels. This can lead to an abnormal blood supply to tissues, providing tumours with the nutrients and oxygen they need to grow and spread.

Oral cancer: Tobacco uses significantly increases the risk of cancers in the mouth and throat due to direct contact with carcinogens. Smokeless tobacco products, such as chewing tobacco, also contribute to oral cancers by exposing the mucous membranes to high concentrations of carcinogens.