By: Ajay Shah (2nd Year)
In our first article of 2016, Ajay Shah writes about his experience with the news headlines’ exaggeration of research paper results and discovering how to interpret them.
On October 26th, 2015, the results of a new study rippled across social media and news outlets. Sensationalist Twitter hashtags and Facebook posts lamenting its results dominated the cyber landscape. Sales at supermarkets and grocery stores fell by millions of pounds in the following weeks. Thousands of people swore off their favourite foods in the panic, hoping to bargain for a few extra years of life. What could this study have discovered to cause such a viral reaction throughout society? Well, of course, it showed that bacon causes cancer!
Hold up. What? One of the most universally loved foods in the world (Americans consume 18 pounds per capita annually), cast aside by a suddenly health-conscious population, just because of one study’s results? How could this have happened? As is often the case, the culprit is not those responsible for creating the study (they just did the science), nor the general population (we just read the articles). The culprit is far more insidious, something capable of unnecessarily inspiring fear into millions of innocent people. That culprit was The Headlines.
I woke up that morning to see a short BBC notification on my phone declaring that red meat causes cancer. Confused, I called my girlfriend as I skimmed the article.
“WHAT??” said my girlfriend when I read the headline to her, likely picturing morsels of steak morphing into tumours as they passed through her colon.
“Yup, the WHO has declared that red meats cause colon cancer. It’s true – even the BBC is reporting it,” I replied.
After some quick research, and reading headlines and tweets such as:
“OMG! Bacon causes cancer!” (New York Post)
“Processed meats rank alongside smoking as cancer causes — W.H.O. U.N. health body says bacon, sausages and ham among most carcinogenic substances along with cigarettes, alcohol, asbestos and arsenic.” (The Guardian)
“Bacon, hot dogs and processed meats cause cancer/are as dangerous as smoking, says @WHO.” (PBS)
the alarm bells began to ring. My girlfriend quickly swore off processed meats for life, and limited red meats to one meal per week. I, an avid meat-eater myself, decided not to let The Headlines fool me, and began to do some research of my own.
As I had suspected, the initial reaction to the study was quite overblown. In fact, the first paragraph of the WHO report itself says that “red meat is probably carcinogenic to humans based on limited evidence ”. “Limited evidence” means that, while a positive correlation is present between the exposure (meat) and outcome (cancer), other explanations (confounding factors, bias, chance) cannot be ruled out.
The findings are based on an assessment of more than 800 studies, which gave more weight to the studies with larger sample sizes, fewer confounding factors and better experimental design. Approximately two thirds of the case-control/cohort studies showed a positive correlation between eating processed meats and colorectal cancer incidence. It was found that eating 100g of red meat per day raises colorectal cancer incidence by 17%, while eating 50g of processed meat daily raises incidence by 18%. Both types of meat consumption were also linked to pancreatic, prostate and stomach cancer.
Personally, I think that the study was very well-conducted and is a fantastic example of “Good Science”. The researchers importantly identified a mechanism of action, identifying known carcinogens produced during the cooking of meat, and postulating that these compounds lead to cancer formation. They also examined a wide range of studies under specific criteria, minimizing the influence of confounding factors and bias. The different types of meats were classified appropriately, and suitable recommendations were made.
Upon reading the WHO report, I felt quite upset at the media for their treatment of the story. The WHO researchers were quick to reassure, suggesting that a reduction of processed meat consumption would be a preferable alternative to widespread vegetarianism. Indeed, they identified the valuable nutrients and compounds in red meat, and after contrasting these with the increased cancer risks, officially only recommended cutting down red meat consumption to 70g daily. This is a stark contrast to the doom-and-gloom picture portrayed by the media.
An increase of cancer incidence by 17-18% may seem like a lot, and with the media’s handling of this report, any meat eater would do a double-take before chowing into that cheeseburger. However, this “relative risk” looks a lot different when put into perspective. It is estimated that, among 1000 people who eat little-to-no processed meat, 56 would develop bowel cancer during their lives. Comparatively, of the 1000 people who eat the most processed meat, 66 are expected to develop bowel cancer during their lives. Indeed, the 17% increase seems miniscule when compared to smoking (2,400% increased risk) or drinking alcohol (500% increase). And this ignores the fact that red meat offers many healthy nutrients, which may overpower the carcinogenic effect in some. Regardless, red and processed meat now joins an increasingly cluttered list of carcinogens, including aloe vera (Class 2B), the Sun (Class 1) and Air (Class 1), some of most dangerous things known to man.
So, throughout the journey from “my bowels are full of carcinogen-induced tumours” to “eating meat probably, might, slightly increase the risk of developing a tumour in my large intestine”, I learned a lot about clinical studies, the media, and The Headlines. I learned that “carcinogen” is a broad term, and a subatomic particle that may be essential to the fabric of our reality (neutrons) is also a known human killer. I learned that clinical studies completed under similar conditions could have polar opposite results. But most importantly, I learned that in a world dominated by clickbait headlines and diminishing attention spans, the onus is on us to do our research, and Rewrite the Headlines.