Disease, lifestyle choices and risk: untangling myth from reality

Sunday 14 October, 16:0017:15, ConservatoryBiomedical dilemmas

Hardly a day goes by without new reports about how some aspect of our lifestyles threatens our health. Whether it is our diets, our alcohol consumption or the air that we breathe in cities, modern life seems to be full of threats. Indeed, claims about our unhealthy habits are so frequent and contradictory that it is tempting to throw our arms up and declare that lifestyle advice is meaningless and we know nothing. Yet there has been a huge amount of research on these areas, surely we can learn something from it?

One area of ill health that has received an enormous amount of coverage is breast cancer, something that millions of women will have to face at some point during their lives. The disease is the subject of many celebrity stories and considerable charitable fund-raising. Alcohol consumption, diet and physical activity are among the many lifestyle choices that are frequently mentioned as risk factors for breast cancer. It is widely claimed that a woman can reduce her risk of developing breast cancer by 50 to 80 per cent by making the right lifestyle choices.

But is it true? Two breast cancer experts, Professor Trisha Greenhalgh and Dr Liz O’Riordan, have questioned these claims in a new book, The Complete Guide to Breast Cancer: how to feel empowered and take control. For example, they note that there is no single food that has been shown to cause breast cancer, nor is there any single food that will protect you from developing it or prevent it recurring. While red meat has been linked to a very small increase in breast cancer rates, the risk of developing breast cancer does not differ among people who identify as vegetarian, pesco-vegetarian or non-vegetarian. For obesity, they found that the proportion of pre-menopausal breast cancers that are attributable to being overweight or obese is zero; for post-menopausal breast cancers, the figure is around five per cent.

So how do we navigate through these claims about lifestyle and risk? Is it possible to find some nuance beyond the scary headlines? Are there easy ways for lay readers to discern where their lifestyles could significantly increase the risk of disease? Even if we do decide that replacing fries with salad or going for a daily run would lengthen our lifespans, should we necessarily put longevity ahead of pleasure? Do we need to learn to think about ethics and freedom as much as statistics in order to make the right choices?