Monday, August 02, 2010

Do Cold Cuts Cause Cancer? The Making of a Misnomer

The problem with most modern 'journalism' is that it's done by people like me.

Writers are, on the whole, an unscrupulous bunch who'll twist the facts like a pretzel as long as it supports whatever attention-grabbing headline it is they're trying to flog.

A good case in point was the recent 'sunscreen controversy' - in which thousands cast aside the SPF 35 in the mistaken belief that sunscreen actually caused, rather than prevented, cancer.

Compounding that problem was the fact that there are reams of people who'll only ever read the headline of an article and never bother to consider the facts themselves.

'Does sunscreen cause cancer?' became 'Sunscreen definitely causes cancer' and before you knew it, people are out in the midday sun cultivating their melanoma with reckless abandon.

For today's post, I thought I'd deconstruct the process and reveal what a crock most of these articles are - and why you should be very wary about how many of these frightening headlines you choose to believe.

A good place to start is this article, released today on Yahoo:
Cold cuts could cause cancer: study

Already linked with an increased risk of cardiovascular disease and certain cancers, including cancer of the pancreas, red meat cold cuts were found by a team of US researchers to be a possible cause of bladder cancer, a study published in the journal Cancer said. Full story here.
Based on this article, cue thousands of parents throwing out their cuts of cold roast beef, and banning their kids from eating at Subway and Arbys. Cue officious idiots sneering at strangers: "Oh, you shouldn't feed your child cold cuts. They cause cancer, you know."

But do they? Is there really any weight to this theory at all? What most people fail to do is actually look at the big picture, and work out for themselves whether they really have anything to be worried about.

In this instance, there are certain subtle nuances you won't get if you simply read the headline. For example:
The culprits in the cold cuts are nitrates and nitrites which are added to meat when it is processed to preserve and enhance color and flavor.
So for a start, cold cuts aren't really what causes cancer - a chemical sometimes found in them is. It's also a chemical found in a host of other substances, including wine and even fresh green vegetables (in fact, most nitrate-poisoning occurs amongst vegetarians who have eaten too much green produce, which is fertilized with nitrates.)

But lets dig further into the 'meat' of the study, like this passage:
For the study, scientists assessed the intake of nitrates, nitrites and other components found in red meat, in some 300,00 men and women aged 50-71 year, in eight US states, and its relation to cancer. The study participants were followed up for up to eight years. During that time, 854 were diagnosed with cancer of the bladder.

First of all, what the hell is '300,00' meant to be? Did the journalist mean 30,000? Did he get the comma right, but miss out a final zero - 300,000? Or was the comma meant to be a period, meaning that the study consisted of 300.00 subjects, all of whom died at least twice from bladder cancer (and some more than that.)

The significance is enormous. The study concludes that the subjects who had a high intake of nitrates had a "28 to 29 percent greater chance of developing cancer." Depending on the figures, that's an increase of .5% or .05% - which takes it from a dangerously significant figure to one among thousands (a risk factor that lovers of cold roast beef sandwiches might be willing to live with.)

Finally, the last significant headline omission was this:

The scientists also found that people who ate the most red meat were less educated, less physically active, and had lower dietary intake of fruits, vegetable, and vitamins C and E than those consuming the least red meat. They also found that they were more likely to be current smokers, to have a higher BMI, and to consume more beverages and total energy daily.

That ultimately shows that the group with the increased risk of bladder cancer weren't just classified as those who ate cold cuts. Compared to the group that didn't develop cancer, they were fatter (obesity is a big trigger for cancer) more likely to smoke (another trigger for cancer) and ate less vegetables and fruit (which contain cancer-busting antioxidants.) In short, there were a whole host of lifestyle factors that made these people more likely to develop cancer, so pinning it on cold cuts seems wildly misleading.

In fact, the title of the article should really have been: "Being overweight, smoking and not eating vegetables could cause cancer: study." But that's hardly news now, is it? And not likely to generate the kind of paranoid, misinformed buzz that online journalists are aiming for.

So don't start skipping your turkey and swiss quite yet - as you can see, the facts aren't quite as clear cut as this article would like you to think they are. More importantly, make sure you point out to anybody who's giving up cold cuts because of what they read on Yahoo that they should really stop being such lemmings and have an original thought of their own once in a while.

Finally, a more succinct version of what I explained here today:

3 comments:

CK said...

Isn't this how Al Gore did it?

Roland Hulme said...

Yes.

Can't even argue with you on that one, because An Inconvenient Truth was pure smoke and mirrors. Even I - Mr Global Warming - will admit that.

Susanne said...

excellent post