Ghanaians were recently hit with the scary news that up to 90% of palm oil sold in markets in our capital is contaminated with the cancer-causing colouring agent Sudan IV. This revelation coincided with the WHO’s announcement on October 26 that processed meat (e.g. hot dogs (frankfurters), ham, sausages, corned beef, and canned meat) is carcinogenic.
In the recent past also, liver cancer-causing aflatoxins were found in groundnuts and maize, and some apples sold on the streets were discovered to contain formaldehyde, also a carcinogen.
We have traditionally known agents like radiation, cigarette smoke and certain industrial chemicals to be the carcinogenic substances we need to avoid. However, recent revelations and discoveries suggest that exposure to carcinogens is commoner than we think.
The list of carcinogens is getting longer by the day, and now includes items that were previously thought to be harmless, and even healthy in some cases.
What else is carcinogenic?
A carcinogen is any substance that is directly involved in causing cancer. These agents may be found in the workplace, at home, in our food, in nature (e.g. ultraviolet light), through environmental pollution and may even emanate from medical treatment (e.g. radiation therapy and chemotherapy).
Many substances are inherently carcinogenic, but before they can be confidently classified as such, there needs to be evidence to support that claim. Such evidence is difficult to obtain because of ethical issues surrounding human testing and the shear implausibility of linking a cancer to a specific agent, when so many other agents can confound such a link. It thus takes many years of animal studies, meta-analyses of results of previous studies and fluke discoveries to be able to confidently identify a carcinogen as such.
It is therefore not surprising that as the body of knowledge in cancer research is increasing, more and more substances are being discovered to be carcinogenic.
The WHO’s International Agency for Research on Cancer (IARC) has over the past 3 decades studied over 900 substances and exposures in terms of their carcinogenicity. More than half of these agents still remain is the group “unclassifiable” because there is not enough evidence to make a confident pronouncement on them.
Only about 100 agents are classified by the IARC as “carcinogenic to humans.” This list expectedly includes culprits like X-radiation, asbestos and tobacco smoke, but also includes entries like alcoholic beverages, indoor emissions from household combustion of coal, coal-tar pitch, estrogen-progestogen oral contraceptives (combined), outdoor air pollution (and the particulate matter in it), processed meat (consumption of), salted fish (Chinese-style) and wood dust.
It really does seem just about everything around us is potentially carcinogenic.
What is the solution?
As apocalyptic as recent revelations seem, there is always a good amount of mollification with every such mundane announcement: in the least, the realization that item A or B is carcinogenic helps us consciously avoid it, thereby reducing our risk for the cancer it causes.
We should also bear in mind that the extent of exposure to a carcinogen is important in the occurrence of cancer. The mere fact that you eat processed meat does not mean you will develop colorectal cancer. The authors of that publication actually state that “for an individual, the risk of developing colorectal cancer because of their consumption of processed meat remains small, but this risk increases with the amount of meat consumed,”
They go on to advice that “the findings should serve as a guide to governments and regulatory agencies to conduct risk assessments, in order to balance the risks and benefits of eating red meat and processed meat and to provide the best possible dietary recommendations.” Such recommendations will help us know how to manage our consumption to maximize benefit and minimize risk.
Limiting exposure to the barest minimum thus seems to be the way to go. In every situation consider whether an exposure can be avoided. For instance, not every cough demands a chest X-ray, working with carcinogenic chemicals without protective equipment must never be allowed and palm oil that seems “too red” should be avoided.
While we devise novel ways to deal with new threats, there are basic strategies we can employ to prevent cancer in general. The American Society of Clinical Oncology suggests these 5:
Tip 1: Eat a healthy diet, be physically active, and maintain a healthy weight.
Obesity now affects 20% to 40% of adolescents worldwide. This is an issue because being overweight or obese is strongly linked to an increased risk of developing bowel, breast, uterine, ovarian, pancreatic, esophageal, kidney, and gallbladder cancers later in life. Eat right and exercise regularly to maintain a healthy weight.
Tip 2: Limit the amount of alcohol you drink.
Drinking alcohol is strongly linked with an increased risk of a number of different cancers, including cancers of the mouth, pharynx, larynx, esophagus, bowel, liver and breast. People who have a high risk for these cancers should talk with their doctors about limiting or even avoiding alcohol to help decrease their risk.
Tip 3: Stop using tobacco.
Tobacco causes at least 22% of all cancer deaths. Talk with your doctor about which approach may work best for you.
Tip 4: Be aware of what you’re breathing.
According to the World Health Organization, the environment contributes to an estimated 19% of cancer diagnoses. An important environmental risk factor for lung cancer is air pollution. To help reduce this risk, use protective breathing equipment if you work with asbestos or other cancer-causing substances.
Tip 5: Take precautions against cancer-causing viruses.
Chronic infections cause about 16% of all cancers worldwide. Several of the most common cancers are linked to infections with cancer-causing viruses. The hepatitis B virus (HBV) is a risk factor for liver cancer, while the human papillomavirus (HPV) is a risk factor for cervical cancer. There are vaccines that protect against both of these viruses. You can also reduce your risk of HPV infection by limiting the number of sexual partners you have.
There is no certainty that what we think is safe today will remain so tomorrow. What we are sure of though is that we have no reason not to protect ourselves from the things which have been proven to be dangerous. The least we can do is try to be safe.
By: K.T. Nimako (MB ChB)
Dr. Kojo Nimako is a private medical practitioner with an interest in public health and Citi FM’s Chief Medical Correspondent. He is also the Executive Director of Helping Hand Medical Outreach, an NGO focused on health education.
E-mail: [email protected]
Twitter: @KTNimako