5 Cancer Myths Exposed

We have all seen it before, Facebook and Twitter posts of cancer facts, shared and re-tweeted across the sea of social media. Sometimes it’s obvious when an article is fake or trying to sell you something, sometimes it’s straight forward when it comes from a trusted source as real, but sometimes it blurs the lines into the realm of half-truths and pseudo-science and it can be hard to tell what is true. Have no fear, I’m here to help, here are 5 cancer myths exposed!

[Sugar Photo by By Veganbaking.net CC-BY-SA-2.0]

Myth 1) “Sugar Causes/Feeds Cancer”

I’ve seen this one quite a bit recently and a paramedic friend of mine even shared an article on Facebook saying the same thing. It’s understandable to get fooled by this statement because it’s not entirely wrong, it’s based on a half-truth and the resulting implications can be very misleading.

So does sugar feed cancer? All carbohydrates you eat are broken down into sugar (their monosaccharaide subunits) and it is true that sugar is the fuel for all your cells, including the cancer cells. That’s what makes this myth so tempting to believe, because cells are powered by sugar. These statements are normally followed by some kind diet to cut out refined sugar or to buy some health book or product. However, there is no data to support the claim that eating refined sugar will ‘feed’ your cancer.

The only relationship between sugar and cancer is an indirect one, and not in a ‘feed/cause cancer’ type of way. If you consume too many calories it can contribute to excess weight gain. If this gets out of control it may lead to obesity. Obesity has been linked to an increased risk in developing cancer.

Myth 2) “Milk and Dairy Cause Cancer”

Although this myth died out, it has come back with a vengeance thanks to social media, fad diets, and some interesting studies on calcium. Calcium of course is found in many non-dairy food sources, but it is associated with milk products to the point of being iconic (you hardly ever hear of vegan diet ban on tofu or sesame seeds).

Milk and low amounts of calcium supplements (200mg per day) may lower breast cancer risk. The problem occurs when you get to extremely high levels (as it is with everything including water or oxygen) and at >1500mg a day may increase risk of developing prostate cancer.

But there is no data showing that moderate amounts of dairy and a little calcium supplements (because not everyone can get their required calcium from diet alone) will cause cancer.

Myth 3) “Microwaving food in Plastic Wrap Causes Cancer”

Recently there has been a surge of email forwards and blog posts on this topic, claiming that dioxins and phthalates in plastic cause cancer. This plays on the fear that these substances are harmful and that we make the conscious choice to use them.

This myth falls short however because there are no dioxins in plastic, and (at least in the United States and Canada) phthalates haven’t been used in plastic wrap in a very long time.

You do however always want to follow the manufactures instructions when cooking with plastic wrap, and you should avoid contact with it while your food is in the microwave.

Myth 4) “Strong Immune Systems Stop Tumors”

Again, this one is most commonly seen associated with a brand or website trying to sell you something to boost your immune system. Sometimes it’s the latest super food or some high dose anti-oxidant pill but either way they seem to miss the point on how the immune system fights off cancer.

Throughout a normal person’s life various cells will go out of control and ignore their normal cell death fate (apoptosis or programmed cell death). In many cases this triggers responses in the cell that produce specialized proteins that are then displayed on the cell membrane for the immune system to recognize. A similar distress signal is used when some viruses and bacteria infect cells. The immune system recognizes the distress response and destroys the cells. But that has nothing to do with a strong or weak immune system.

In the case of tumor formation the cells have lost their ability to shout “”Hey I’m out of control, come kill me!”. The immune system is basically blind to these cells as they look just like all your other normal cells. You wouldn’t want your immune system to attack cells that look normal, when that happens it’s a bad thing (lupus, diabetes, etc).

Myth 5) “Stress and Anxiety cause Cancer”

Stress can cause a variety of health problems; however the evidence for stress causing cancer is weak at best. There are a few studies that link an increased risk of cancer with psychological factors, but there are many more studies that have failed to find evidence that people who are anxious or stressed are any more likely to develop cancer than people who are more relaxed.

A meta-analysis study published in 2013 looking at 116,000 European men and women found that work stress was not associated with colorectal, lung, breast or prostate cancer. As of now, there just doesn’t appear to be a cancer personality type.

There are several explanations that may account for the apparent link between cancer and stress. People who are stressed may take on habits or behaviours such as smoking, overeating, and alcohol consumption, all of which are known risk factors for cancer.

References:

• Katriina Heikkilä, Solja T Nyberg et al, Work stress and risk of cancer: meta-analysis of 5700 incident cancer events in 116 000 European men and women BMJ 2013; 346 doi: (Published 7 February 2013)
• University of California, San Francisco (UCSF)
• Patricia A. Enneking, Phthalates Not in Plastic Food Packaging, Environ Health Perspect. 2006 February; 114(2): A89–A90. Correspondence
• Johns Hopkins Medicine