with the rising incidence of cancers across globe it is pertinent to dwell into what factors are contributing to this rise:
Often, the underlying reasons that determine the development of cancer in cells are - 1) Carcinogen – which is a harmful substance having the capacity to induce cancer and 2) A more neglected aspect for cancer causation - Immune system. Both these factors play a pivotal role to prevent cancers from occurring in body.
While there has been much concern raised in the recent years about carcinogens, it but stands to fact that “Everything under the sun including the Sun itself could be a potential carcinogen!”. Typically carcinogens are divided into following category:
- Physical carcinogens, such as ultraviolet and ionizing radiation;
- Chemical carcinogens, such as asbestos, components of tobacco smoke, aflatoxin (a food contaminant) and arsenic (a drinking water contaminant); and
- Biological carcinogens, such as infections from certain viruses, bacteria or parasites.
Hence our body is constantly exposed to ill effects of carcinogens. However not all of us become victims to cancer owing to this exposure. This is where the play of immune system comes to light. This indistinct yet powerful tool called immune system has been a topic of much debate, discussion and many times controversial. However, there is not much doubt to deny the role of immune system to repair and restore the damaged cells that are on the path towards transforming into cancer.
Finally, the story of cancer causation largely boils to a few recurrent and largely preventable causes:
·Diet & Nutrition
The most common causes of cancer are
1.Habits – Tobacco, alcohol – 30% to as high as 50% of the cancers are related to habits, with tobacco being a significant contributor. Tobacco is more harmful and dangerous as this product contains deadly addictive chemical called nicotine and about 4000 to 6000 other chemicals. IARC and other international bodies have identified upto 60 carcinogens in these products such as benzopyrenes, nitroamines, formaldehydes, heavy metals such as arsenic, nickel etc.
Unlike tobacco, alcohol has mainly one carcinogen – aldehydes. However, alcohol and tobacco have been old friends and for consumers who use both products, Alcohol is an excellent solvent and hence amplifies the cancerous action of tobacco by dissolving the carcinogens and helping them penetrate better into the cells.This makes the not to say, that alcohol is safer by itself. But the addictive potential of tobacco makes this habit more lethal.
2.Diet & Nutrition
I have divided this section into Diet and nutrition which needs to be looked at from two different viewpoints in present rapidly changing times. The present era is aptly called “instant, unlimited and more” Era, and our dietary patterns have so been modified to suit this era.As most of present generation is looking at instant solutions be it instant food or success, unlimited food in form of buffets and more (buy one get one or 20% extra!). This increasing demand for ready-to-eat fresh food products has led to challenges for food distributors regarding the safety and quality of their foods.
Diet - Diet in today’s world could contribute to significant load of carcinogens from the use of preservatives and pesticides used in food products and beverages.
·Preservatives - In an ideal situation, Preservatives in food help keep the food safe, without spoiling, for longer. However, many of these preservatives could react with proteins to form harmful cancerous substances. For Eg: Sodium nitrite is a preservative used in lunch meats, hams, sausages, hot dogs, and bacon to prevent botulism. It serves the important function of controlling the bacteria that cause botulism, but sodium nitrite can react with proteins, or during cooking at high heats, to form carcinogenic N-nitrosamines.
Generally four classes of preservatives are known according to the various inspection agencies the world over. Class-I Preservative and Class-II Preservative are some of the widely used preservatives used for preserving foods. Class I preservatives are generally preservatives that are found in the common kitchen and includes salt, vinegar, salt, vegetable oil, honey, sugar and wood smoke. When Class-I Preservative is found in the nature, Class-II Preservative is manmade and are unnatural preservatives. Sorbates, sulfites and benzoates are some of the Class II preservatives used. Hence one needs to be careful when using Class II preservatives as they are chemicals such as:
1.Sulfites are often found in wines and dried fruits.
2.Propionic acid (PPA) is a common preservative found in commercial bread.
3.Nitrates are found meats and cheeses
4.Sodium Benzoate is used to preserve soda, juice, pickles, salsa and cosmetics.
5.BHA and BHT are found in fats, oils, snacks, cereals, and instant potatoes.
6.Tertiary butylhydroquinone (TBHQ) is added to vegetable oils and some animal fats.
·Pesticides – there has been a growing concern about the use of pesticides in fruits and vegetables across the world. Pesticides and herbicides can be toxic when used improperly in industrial, agricultural, or other occupational settings. While up to 10 cancer cases per year could be caused by the added pesticide consumption, the resulting estimates are that approximately 20,000 cancer cases per year could be prevented by increasing fruit and vegetable consumption. At present there is no evidence that residues of pesticides and herbicides at the low doses found in foods increase the risk of cancer.
Although vegetables and fruits sometimes contain low levels of these chemicals, overwhelming scientific evidence supports the overall health benefits and cancer-protective effects of eating vegetables and fruits. The overwhelming difference between benefit and risk estimates provides confidence that consumers should not be concerned about cancer risks from consuming conventionally-grown fruits and vegetables. Nonetheless, fruits and vegetables should be washed thoroughly before consumption to minimize the residual pesticides.
Having said this, it is important to understand that there are no strict measures to control and regulate the amount of usage of pesticides or banned chemicals in vegetable / fruits among farmers in India. The insecticide act of India 1968 is a weak and superseded legislation which should be replaced by the Pesticides Management Bill 2008. The Union Cabinet gave its approval for the introduction of this bill on April 24, 2008 but is yet to come in force.
The Bill aims at improving the quality of pesticides available to Indian farmers and introducing new, safe and efficacious pesticides.
·Nutrition – Nutrition is the vital dimension of diet that protects and promotes the intangible defense mechanism of the body through the immune system. Nutrition provides energy and stability to the system, but recent trends have drifted into dietary system rich in calories and poor in nutrition. Our daily diet obviously lacks the nutritional punch that it receives from proteins, vitamins and minerals from natural organic resources. These form the building blocks of the body that create strong walls of defense from carcinogens and prevent oxidative damage which is thought to be involved in the development of cancer by causing direct damage to the DNA. It is also important to revisit the previous discussion on pesticides at this point that while up to 10 cancer cases per year could be caused by the added pesticide consumption, the resulting estimates are that approximately 20,000 cancer cases per year could be prevented by increasing fruit and vegetable consumption.
3.Infections - Worldwide 16.1% of cancers are related to infectious diseases. Infections from Viruses, bacteria and parasites are a potential biological carcinogen. Common viruses that are known include human papillomaviruscausing cervical carcinoma, Epstein-Barr virus casuing B-cell lymphoproliferative disease and nasopharyngeal carcinoma, Kaposi's sarcoma herpesvirus (Kaposi's Sarcoma and primary effusion lymphomas), hepatitis B and hepatitis C viruses (hepatocellular carcinoma), and Human T-cell leukemia virus-1 (T-cell leukemias). Bacterial infection may also increase the risk of cancer, as seen in Helicobacter pylori-induced gastric carcinoma. Parasitic infections strongly associated with cancer include Schistosoma haematobium (squamous cell carcinoma of the bladder) and the liver flukes, Opisthorchis viverrini and Clonorchis sinensis (cholangiocarcinoma)
4.Environment - Environmental carcinogens, in a strict sense, include outdoor and indoor air pollutants, as well as soil and drinking water contaminants. Ambient air pollution has been implicated as a cause of various health effects, including cancer. Recently, The specialized cancer agency of the World Health Organization, the International Agency for Research on Cancer (IARC), has classified outdoor air pollution as carcinogenic to humans (Group 1). The predominant sources of outdoor air pollution are transportation, stationary power generation, industrial and agricultural emissions, and residential heating and cooking. Some air pollutants have natural sources, as well.
5.Physical activity - Clearly research shows that physical activity can help reduce the risk of lot of cancers. In fact, physical activity not only maintains the tone of the body, but also helps regulate several important hormones, alertness and immune system that acting as an important preventive oncology tool. It also helps to keep a check on obesity and overweight which are undoubtedly high risk factors for cancer with physical inactivity being an important contributor to this.