What Causes Cancer?

Photo: Our grateful thanks to Vitolda Klein on Unsplash!

What causes cancer? Here begins the annoyingly scientific but mercifully short answer:

Errors in DNA genetic transcription influence how our body’s cells born, grow, and divide.

Normal cells have a programmed lifespan that’s programmed by our DNA. When the normal cells die, they are replaced by cells that are patterned by the same genetic code.

If the DNA code is damaged,  cancer cells form. These cells grow uncontrollably and form tumors that can spread to other parts of the body.

Now we’re getting down to the relevant practical issues.

DNA damage that can lead to cancer can have many causes:  

  1. The World Health Organization (WHO) estimated that between 2015 and 2020 the worldwide cancer rate grew by 57 percent.

They associated the increased cancer rate with a dramatic rise in the use of untested chemicals in industry and consumer products, including food growing and processing.

DNA can be damaged by natural or man-made chemicals in the environment; these substances are called carcinogens. They are found in asbestos, certain components of tobacco smoke which contains over 50 known carcinogens, aflatoxin (a food contaminant), asbestos, arsenic (a drinking water contaminant), herbicides, pesticides, food preservatives and colorings, paints, clothing, plastics – and as you’ve probably guessed, the list goes on and on.

WHO estimates that more than 160 million chemicals are known to humans, of which about 40,000 to 60,000 are used in commerce, and 6000 of these account for more than 99% of the total volume of chemicals in commerce globally.

  1. Physical carcinogens, like the sun’s ultraviolet rays. Up to 10% of invasive cancers are related to radiation exposure.  Medical use of ionizing radiation is a growing source of radiation-induced cancers. Ionizing radiation may be used to treat other cancers, but this treatment may, in some cases, induce a second form of cancer.
  2. Biological carcinogens, such as infections from certain viruses, bacteria, or parasites. Approximately 13% of cancers diagnosed in 2018 globally were attributed to carcinogenic infections, including Helicobacter pylori, human papillomavirus (HPV), hepatitis B virus, hepatitis C virus, and Epstein-Barr virus.
  3. Lifestyle choices such as food, alcohol, and physical activity. Together, diet and obesity are related to approximately 30% to 35% of cancer deaths. Dietary recommendations for cancer prevention typically include an emphasis on vegetables, fruit, whole grains, and fish, and avoidance of processed meat, red meat, animal fats, and refined carbohydrates.

In Western Europe, 10% of cancers in males and 3% of cancers in females are attributed to alcohol. In particular, alcohol use has been shown to increase the risk of developing cancers of the mouth, esophagus, pharynx, larynx, stomach, liver, ovaries, and colon.

Individuals who eat red or processed meats have a higher risk of developing breast cancer, prostate cancer, and pancreatic cancer.

The relationship between diet and the development of particular cancers may partially explain the differences in cancer incidence between countries. Gastric cancer is more common in Japan due to the frequency of high-salt diets, and colon cancer is more common in the U.S. due to the increased intake of processed and red meats.

  1. Hormones are important agents in gender-related cancers such as cancer of the breast, endometrium, prostate, ovary, testes, thyroid, and bones.

For example, the daughters of women who have breast cancer have significantly higher levels of certain estrogen metabolites and progesterone than the daughters of women without breast cancer. The higher estrogen metabolite levels may explain why these women have a higher risk of breast cancer, even in the absence of a breast-cancer gene.

Similarly, men of African ancestry have significantly higher levels of testosterone than men of European ancestry and have a correspondingly much higher level of prostate cancer.

  1. Chronic Inflammation can lead to DNA damage over time and an accumulation of random genetic alterations in cancer cells. Individuals with inflammatory bowel disease are at increased risk of developing colorectal cancers.
  2. Not all types of electromagnetic radiation are proven carcinogens. Low-energy waves on the electromagnetic spectrum, including radio waves, microwaves, infrared radiation, and visible light, are now thought not to be cancer-promoting because they have insufficient energy to break chemical bonds.  But the jury is still out on this, as some interesting new studies are emerging.  Radiation from mobile phones, electric power transmission equipment and lines, and similar sources have been described as a possible carcinogen by the WHO.

Reducing the burden. Between 30% and 50% of cancers can currently be prevented by avoiding the known risk factors and implementing existing evidence-based prevention strategies.

The cancer burden can also be reduced through early detection of cancer and appropriate treatment and care of patients who develop cancer. Many cancers have a high chance of cure, if diagnosed early and treated appropriately.

For information about the services we offer, we invite you to get in touch in any of these convenient ways: (1) give us a call at 650-961-1660, (2) use the Contact Form, or (3) follow the link to Consultations – Pacific Naturopathic. Thank you!