The media’s appetite for things that cause or prevent cancer can be as notable for its sheer volume as for – in some cases – its hype. And food is a key area of interest, because everyone can relate to the latest headlines on bacon or broccoli.
Rarely a week goes by without headlines on the latest “cancer-busting” food or, at the other end of the spectrum, the unexpected perils of pop. So a research article with the intriguing title ‘Is everything we eat associated with cancer? A systematic cookbook review‘, published in the American Journal of Clinical Nutrition recently, couldn’t fail to catch our attention.
This review looked at a selection of cookbook ingredients to see if they had been investigated for links to cancer. The researchers found that most of the 50 foods they looked at had been associated with an increased or decreased cancer risk in the scientific literature.
But is this a testament to the power of different foods over our chance of developing cancer? Or is it proof that scientists just can’t make their mind up?
In fact it’s neither. The most important finding of the review was that single studies often found links that had only weak evidence behind them.
The research provokes thoughts about why we do research, how much one study on its own can tell us, and the value of considering the balance of evidence.
Perhaps most importantly, is also raises questions about how much detail scientists and the media provide as context when they present results to the public.
And rather ironically, and worryingly, one paper decided this study warranted the conclusion that there is ‘no proven link between foods and cancer’. This is clearly not the case, as we explain below.