Rob Lyons on the latest cancer study, which makes unsubstantiated claims about the “lifestyle” causes of cancer:
The essential idea we are being sold here is that medical experts know that certain behaviours — like smoking, drinking alcohol, eating read meat and not eating enough fruit and vegetables — increase your risk of developing cancer by a certain percentage. So, all we need to do is work out how many people would have got cancer if no one did any of those things, take that number away from the number of people who do get cancer, and the remainder is how many people that ‘unhealthy living’ is killing. Simple, right?
According to the report, If you do all the ‘right’ things — if you are a cigarette-dodging, skinny teetotaller who avoids all red meat, barely goes out in the sun (except, perhaps, to take the prescribed 30-minute sessions of exercise five times per week), gets lashings of fibre, cuts down on salt, avoids infectious diseases and ionising radiation, and so on — then you can cut your cancer risk by over 40 per cent. On that basis, you may avoid cancer but die of boredom instead.
More specifically, even in this report there’s a huge gulf between the widely acknowledged risk of smoking — which is estimated here to cause 19.4 per cent of all cancers — and other risk factors. Smoking accounts for nearly half the lifestyle risk of 43 per cent claimed in the report. The next biggest factors suggested are overweight and obesity (5.5 per cent), lack of fruit and veg (4.7 per cent), alcohol (4.0 per cent), occupation (3.7 per cent) and sunlight (3.5 per cent). No other single factor, according to the report, is responsible for more than three per cent of cancers. Some oft-quoted examples like salt (0.5 per cent) and physical exercise (one per cent) have little effect at all. Even avoiding red meat altogether would only avoid 2.5 per cent of cancers, says the report.
