Is this the start of the silly season?

Apart from the red wine/breast cancer story Ed blogged about on Tuesday, a couple of other stories in the media this week had us wondering if these were the first signs of silly season taking hold this ‘summer‘.

To kick off the week, the Independent on Sunday warned the nation about the toxic properties of the PVC shower curtains.

Now, Cancer Research UK is all for responsible legislation against potential environmental hazards – indeed, banning smoking in the workplace was perhaps the single biggest blow against environmental carcinogens this country has seen in recent times.

Not peer-reviewed

But rather than coming from a peer-reviewed science journal, this story sprang from a report commissioned by a US campaign group, the Centre for Health, Environment and Justice, who are currently running a campaign called PVC: The Poison Plastic.

We agree with the CHEJ’s sentiment that, where possible, chemicals known to have potentially carcinogenic effects should be replaced by safer alternatives. But whilst it makes its points soberly, the report from which the headline stems is rather heavy on the emotive imagery. And, importantly, fails to present any direct evidence showing that PVC from shower curtains actually causes cancer in people.

In our opinion, adding shower curtains to the list of things we should worry about is perhaps ignoring the bigger picture in terms of cancer prevention.

Prostate cancer and ‘desk work’

The second story concerns desk work and prostate cancer. The headlines proclaimed “prostate cancer risk higher for desk workers“, and offered to explain “why men with desk jobs have higher risk of prostate cancer“.

These stories sprang from a paper published in the European Journal of Cancer Prevention, looking back at data from a Greek study carried out between 1994 and 1997. (co-incidentally, the second time Greek researchers have hit the UK headlines in a fortnight)

The research team looked at the occupations of 504 men with either prostate cancer or benign prostatic hyperplasia along with 246 “patients hospitalized for minor conditions”, i.e. who did not have cancer, for comparison. They graded all of these men according how much exercise they probably did during their working lives.

They found that men with office jobs –  therefore deemed to have a ‘sedentary lifestyle’ – seemed to have a slightly higher risk of developing prostate cancer than men who did ‘manual work’. But importantly, this link wasn’t ‘statistically significant‘ – a technical way of saying it could easily have been down to chance, or experimental error.

But is there a link?

In fact, there’s been quite a lot of research focused on the role of physical activity in prostate cancer but the results have been largely inconsistent, both in terms of how much activity has an effect, and how much of an effect it has.

There’s quite a lot of other evidence, from large, ongoing studies, that does show that physical activity can reduce the risk of other types of cancer – notably breast and bowel cancers. So it makes sense to keep active, despite doubts over this individual paper.

But the inference from these headlines that a sedentary lifestyle, in and of itself, increases a man’s risk of prostate cancer just isn’t supported by the results of this study.

Likewise, no-one’s published any data to suggest shower curtains have caused a single case of human cancer.

So despite the headlines, there’s nothing behind any of them to cause any of us undue worry.

Even if you have a sit-down shower every morning.

Henry