Why Tobacco Causes Cancer?

Tobacco is a major cause of various types of cancer because it contains numerous carcinogens (cancer-causing substances) that can damage DNA and disrupt the normal functioning of cells. Here’s how tobacco use, particularly smoking, contributes to the development of cancer:

  • Chemical Carcinogens: Tobacco smoke contains over 7,000 chemicals, including at least 250 known to be harmful, with more than 60 identified as carcinogens. These carcinogens can directly damage DNA within cells, leading to mutations that can trigger the uncontrolled growth of cells and the development of cancer.
  • Promotion of Tumor Growth: Some components of tobacco smoke can promote the growth of tumors once cancer has already developed, making it more aggressive and difficult to treat.
  • Inflammation: Smoking and tobacco use can cause chronic inflammation in the body. Prolonged inflammation can create an environment conducive to the growth and spread of cancer cells.
  • Reduced Immune Function: Tobacco smoke can impair the immune system’s ability to recognize and eliminate cancer cells. This can allow cancer cells to evade detection and continue to grow.
  • DNA Methylation: Tobacco use can lead to changes in DNA methylation patterns, which can influence gene expression and contribute to cancer development.
  • Formation of Tumor-Promoting Blood Vessels: Smoking can stimulate the formation of new blood vessels in tumors, a process called angiogenesis. This helps tumors acquire the nutrients and oxygen they need to grow.

The carcinogenic effects of tobacco are well-established, and it is a major risk factor for various types of cancer, including lung cancer, mouth cancer, throat cancer, esophageal cancer, bladder cancer, pancreatic cancer, and more. Smoking is the leading preventable cause of cancer worldwide, and quitting smoking is one of the most effective ways to reduce your risk of developing tobacco-related cancers.

It’s important to note that other forms of tobacco use, such as chewing tobacco and snuff, also pose cancer risks due to their tobacco content. Additionally, exposure to secondhand smoke can increase the cancer risk for nonsmokers. Therefore, avoiding all forms of tobacco use and minimizing exposure to secondhand smoke are crucial for cancer prevention.