Cancer often evokes fear in many people, and the numerous myths surrounding cancer does not help. Most of these myths, circulated via email and text messages, and posted on the Internet, concern the cancer risk posed by commonly used items.

Dr Faye Lynette Lim, Senior Consultant from the Division of Radiation Oncology at National Cancer Centre Singapore (NCCS), a member of the SingHealth group, dispels common cancer myths and presents the facts.

8 Common cancer myths and misconceptions

1. Myth: Excessive use of mobile (cellular) phones can cause a brain tumour and specific types of cancer, e.g. skin cancer and testicular cancer.

Fact: Mobile phones don’t cause brain tumours or cancer. Mobile phones use radiofrequency (RF) waves, to send and receive signals from cellular towers. These RF waves are a form of non-ionizing radiation. There is no conclusive evidence to prove that these RF waves can cause a brain tumour or cancer.

The American Food and Drug Administration (FDA), which regulates the safety of mobile phones in the United States says, “The majority of studies published have failed to show an association between exposure to radiofrequency from a cell phone and health problems.”

2. Myth: Heating plastic containers in the microwave can release toxins which cause cancer.

Fact: All plastic containers which say ‘microwave-safe’ are completely safe to use in your microwave oven. However, it’s important to follow the instructions on the container, e.g. remove the lid before use. Plastic containers which are not labeled microwave-safe should not be used in the microwave since they can melt and leak chemicals into your food.

Please note: plastic containers and bottles that contain ready-to-eat foods such as yogurt, cream cheese, mayonnaise and peanut butter are not microwave-safe.

3. Myth: Using plastic bottles to store water or freezing them can cause cancer. Disposable water bottles contain a harmful substance called DEHA and re-using them can cause cancer.

Fact: You can safely store water in plastic bottles as long as the bottle is in good condition and can be cleaned with soap and water to prevent the growth of bacteria. This also holds true for disposable plastic water bottles, which can be re-used as long as they are in good condition.

According to the American Cancer Society, “DEHA is not inherent in the plastic used to make these bottles.” There is also no scientific evidence to suggest that you can’t freeze plastic water bottles.

4. Myth: Using hair dye regularly to colour your hair increases your risk of breast cancer, bladder cancer, non-Hodgkin lymphoma and leukaemia.

Fact: Scientific evidence on the link between personal hair dye use and cancer is mostly inconclusive. Most studies on personal hair dye use and the link to bladder cancer and breast cancer have not found an increased risk. However, some studies do suggest that hairdressers and barbers, who have a high exposure to hair dye and other chemicals, may have an increased risk of bladder cancer.

Due to the lack of conclusive evidence from research studies, the International Agency for Research on Cancer (IARC), part of the World Health Organization, considers hair dye use to be “not classifiable as to its carcinogenicity to humans”.

If you are a regular hair dye user and are concerned about your cancer risk, you would do well to carefully follow the instructions when you apply hair dye. Always use gloves and don’t keep the hair dye on longer than instructed. Alternatively, you can use plant-based hair dyes rather than the commonly used semi-permanent and permanent dyes.

5. Myth: Artificial sweeteners can cause cancer.

Fact: Artificial sweeteners commonly used as sugar substitutes, are safe to use. Studies have been conducted on the safety of these artificial sweeteners, e.g. saccharin, aspartame (NutraSweet and Equal), sucralose (Splenda), acesulfame potassium (Sweet One, Sunett), and there is no conclusive evidence to indicate that they are associated with cancer risk in humans.

6. Myth: Excessive consumption of sugar can worsen your cancer.

Fact: Eating sugar will not worsen your cancer. Studies have not found any link between eating sugar and cancer though a high-sugar diet can cause weight gain and obesity. Obesity is associated with an increased risk of developing some types of cancer, e.g. colon cancer (colorectal cancer) and pancreatic cancer.

7. Myth: Daily use of antiperspirants and deodorants can cause breast cancer.

Fact: Antiperspirants and deodorants are safe to use every day and they don’t cause breast cancer. It is wrongly believed that aluminum and parabens in these personal care products are absorbed through the skin, or through cuts caused by underarm shaving, and cause breast cancer.

A study on the use of underarm perspiration products and cancer, published in the Journal of the National Cancer Institute, found no link between breast cancer risk and antiperspirant use, deodorant use, or underarm shaving.

8. Myth: Wearing a bra can compress the lymphatic system of the breast and cause toxins to accumulate, leading to breast cancer.

Fact: It is completely safe to wear a bra. There is no scientific evidence to link wearing a bra, the type of bra worn (under-wired or non-wired) or the length of time it is worn, with breast cancer risk.

The authors of a new breast cancer study on post-menopausal women, funded by the US National Cancer Institute and published in the issue of Cancer Epidemiology, Biomarkers & Prevention, said “Our results did not support an association between bra wearing and increased breast cancer risk among post-menopausal women.”

Ref: J22

Check out our other articles on cancer:

Top 10 Cancers in Singapore (for Men and Women)

Cancer Causes: Myths and Facts

Top Cancer Prevention Foods

Cancer Diet: Top Foods to Eat and Avoid for Cancer Treatment