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6 surprising cancer risk factors

Bacon and other cured meats have been studied for possible links to cancer. Bacon and other cured meats have been studied for possible links to cancer.

You know that cigarettes and radon and ultraviolet radiation can all cause cancer. Here are six things you may not have realized can increase your risk:


The American Society of Clinical Oncology cites evidence from 2017 that even light drinking can slightly raise a woman’s risk of breast cancer and increase a common type of esophageal cancer. Heavy drinkers are said to face much higher risks of mouth and throat cancer, cancer of the voice box, liver cancer and, to a lesser extent, colorectal cancers.

The lead author of the study, an associate professor at the University of Wisconsin Madison, told the New York Times, “The message is not ‘Don’t drink.’ It’s ‘If you want to reduce your cancer risk, drink less.’ And, ‘If you don’t drink, don’t start.’ It’s different than tobacco, where we say, ‘Never smoke. Don’t start.’ This is a little more subtle.”


Science shows us that cells exposed to high levels of nitrates (such as found in bacon and smoked meats) are at greater risk for DNA modification. “The smoking process of meats is thought to introduce heterocyclic amine byproducts in the food, and the curing process involves nitrate salts that cause nitrosocompounds, which are thought to act as potential mutagens,” according to an article in the journal Nucleic Acids Research. Upstate neuroscientist Frank Middleton, PhD, explains that our cells can respond to these mutations and repair them, but over a person’s lifetime, cells that are continually exposed to these types of mutagens will become less efficient at repair — and cancer may develop.

Oral sex

In the United States, the human papillomavirus is the most common sexually transmitted virus and is the leading cause of oropharyngeal (oral) cancers. Oral sex is one way HPV is transmitted. More than 100 types of HPV exist, half causing warts and other skin infections, and half causing infections of the mucous membranes, says Upstate infectious disease specialist Joseph Domachowske, MD. “Most HPV infections are cleared spontaneously by our own immune system,” he says. But among those that infect the mucous membranes of the genital tract, more than 20 are known to cause cancer.

A vaccine for HPV is recommended for girls and boys before they become sexually active.

Body fat

Evidence consistently shows that excess body fat increases the risk for many common cancers including endometrial cancer, colorectal cancer, liver, kidney or pancreatic cancer, esophageal adenocarcinoma, cancer of the upper part of the stomach, multiple myeloma or a slow-growing brain tumor called meningioma, according to the National Cancer Institute.

In related research, the group says physical activity may reduce the risk of several cancers through other mechanisms, independent of the effect on obesity, including colon cancer, breast cancer and endometrial cancer.


Because of the medications people take after they have undergone an organ transplant, or if they have a disease such as lupus, their immune system is suppressed and less able to detect and destroy cancer cells or fight off infections that cause cancer. Infection with HIV also weakens the immune certain cancers, according to the National Cancer Institute.

Working nights

Long-term night shift work increases the risk of breast cancer in women, according to a 2018 study in the journal Cancer Epidemiology, Biomarkers & Prevention. The study also found increased risks for cancers of the digestive system, skin cancer and lung cancer. Researchers suspect environmental factors of modern society play a role in causing cancer  and that circadian rhythm disruption and nocturnal melatonin suppression could be carcinogenic.

Cancer Care magazine spring 2019 coverThis article appears in the spring 2019 issue of Cancer Care magazine.