Science has authority not because of white coats or titles, but because of precision and transparency: you explain your theory, set out your evidence, and reference the studies that support your case.

In the past, [medicalization]has been portrayed as something that doctors inflict on a passive and un-suspecting world - an expansion of the Medical Empire. But in reality, it seems that these reductionist bio-medical stories can appeal to us all, because complex problems often have depressingly-complex causes, and the solutions can be taxing, and unsatisfactory.

I spend a lot of time talking to people who disagree with me - I would go so far as to say that it's my favourite leisure activity.

Homeopathy pills are, after all, empty little sugar pills which seem to work, and so they embody [..] how we can be misled into thinking that any intervention is more effective than it really is.

If I was writing a lifestyle book it would have the same advice on every page, and you’d know it all already. Eat lots of fruit and vegetables, and live your whole life in every way as well as you can: exercise regularly as part of your daily routine, avoid obesity, don’t drink too much, don’t smoke, and don’t get distracted from the real, basic, simple causes of ill health. But as we will see, even these things are hard to do on your own, and in reality require wholesale social and political changes.

And if, by the end [of this book], you reckon you might still disagree with me, then I offer you this: you'll still be wrong, but you'll be wrong with a lot more panache and flair than you could possibly manage right now.

Doctors and patients need as much data as possible to make an informed decision about what treatment is best.