Smoking:

Tobacco smoke contains a cocktail of chemicals that result in many different forms cancer.

Smoking is the leading cause of Lung & Oral cancers. A  lesser known fact is that smoking is also the causative factor of many other forms of cancer including Stomach, Bowel, Bladder, etc.

Indirect & second hand smoking is equally dangerous and causes cancer.

Unhealthy diet with low fruit and vegetable intake:

Processed food, fatty foods and red meats are strongly linked to a number of different forms of cancers.

Processed food contains harmful colouring & preservative agents, these food also traps a lot of sugar which promotes obesity.  Salty foods irritates the lining  of  our gut. Red meat contains haem which is thought to promote cancer of bowel. Grilled & burnt food also upset our gut lining as the contain harmful free radicals that may cause cell mutation & cancer.

Our diet should contain fresh food and as much fruits and vegetable as possible. Fruits and vegetables contains dietary fibers which not only helps to overcome obesity buts also significantly reduces the chance of bowel cancers

Obesity:

Obesity is the new smoking , one of the greatest public health challenges of our generation. Having BMI of 30 or more means a person is obese.     

Being overweight or obese is clearly linked with an increased risk of many types of cancer. This is because Fat cells release excess levels of growth hormone & other hormones that promotes uncontrolled cell division

Obesity induced cancer includes-  

Breast (in women past menopause), Colon & Rectum , Endometrium , Esophagus , kidney, pancreas. 

Lack of exercise or physical activities:

Lack of exercise leads to obesity which may ultimately result in cancer.  

Drinking Alcohol:

Alcohol contains Acetaldehyde, an organic compound which can damage DNA resulting in cancer.

Alcohol also disrupts our hormone levels which also increase the risk of cancer. Alcohol is known to cause several  types of cancer, including breast, mouth , bowel cancers, etc.

There is no clear health benefits of alcohol, so even mild consumption of alcohol should be avoided.

Exposure to harmful chemicals:

Working in some professions may expose you to some harmful fumes, chemicals, radiation, or other noxious elements  that may trigger cancer later in life.

Agriculture: Exposure to pesticides.

Mining:  Exposure to fumes & dust.

Manufacturing Industries: Exposure to benzene based fumes & diesel engine exhaust

Construction workers: Exposure to Asbestoses.

Radiologist: Exposure to radiation if the setup and protection gear is inadequate.

Tobacco industries: Exposure to tobacco

Prostitution: Exposure to Human Papilloma Virus.

Some studies also indicate that working in night-shifts may increase the risk of certain cancers.

Some special type of Infections :

Infections by some microorganism are known to cause cancer

  • Human Papilloma Virus (HPV)

HPV infection is the number one cause of cervix cancer world wide. In addition, this virus is also known to cause cancer in penis and mouth

  • Helicobacter pylori (H. pylori)

H. pylori increases the risk of stomach cancer and Non hodgkin lymphoma

  •  Epstein Barr virus (EBV)

EBV is linked to cancer, including Hodgkin lymphoma, naso-pharyngeal cancer and Burkitts lymphoma

  •  Human immunodeficiency virus (HIV)

HIV can cause Kaposi Sarcoma, Non-Hodgkin Lymphoma and is also linked to Hodgkin Lymphoma, cervical cancer and anal cancer

  •  Hepatitis B virus (HBV) and hepatitis C virus (HCV)

Long standing HBV infection can cause liver cancer. HCV is alsoKnown to cause liver cancer and  Non-Hodgkin Lymphoma

Old age :

As our body ages, we  accumulate more and more damage in our DNA this often results in cancer.Thus the risk of cancer increase with age .

Family history of Cancer and Genetics:

Certain cancers are linked to faulty genes.  These includes Breast ,  Kidney, Ovarian, prostate, Thyroid cancers, etc.

Exposure to Ionizing Radiation/ Radiotherapy:

A person may get exposed to ionizing radiation  (for example: X-ray, UV rays, gamma rays , etc.)

These high energy radiations damage  our DNA  which may result in cancer.

People may get exposed to radiation naturally, from work (for example while working in lab) or as a part of radiotherapy.

Although Radiotherapy is very effective in treating certain forms of cancer, the radiation itself may trigger a different form of cancer else where in the body.  

Excess exposure to Sun & UV ray :

Ultra violet rays (uv rays) from sun can mutate our skin cells and result in skin cancer.

Our skin has a natural pigment called Melanin. It is the same chemical that gives the dark complexion of our skin.  Melanin  also protects us from the harmful affects of sun’s radiation. However people with lighter skin tone do not enjoy this protection since their skin lacks melanin.

Skin cancer is a major threat to white skinned  people. People with light skin tone should avoid direct sunlight  or apply  sunscreen (at least SPF 15) when going out.