“Children can be disgusting, and often they can develop extraordinary talents, but I’m yet to meet any child who can stimulate his carotid arteries inside his ribcage.”

“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.”

“What can you do? There's the rub. The most important take-home message with diet and health is that anyone who ever expresses anything with certainty is basically wrong, because the evidence for cause and effect in this area is almost always weak and circumstantial, and changing an individual person's diet may not even be where the action is.”

“Like most things in the story the natural sciences can tell about the world, it’s all so beautiful, so gracefully simple, yet so rewardingly complex, so neatly connected—not to mention true—that I can’t even begin to imagine why anyone would ever want to believe some New Age ‘alternative’ nonsense instead. I would go so far as to say that even if we are all under the control of a benevolent God, and the whole of reality turns out to be down to some flaky spiritual ‘energy’ that only alternative therapists can truly harness, that’s still neither so interesting nor so graceful as the most basic stuff I was taught at school about how plants work.”

“Paul Broca, for example, was a famous French craniologist in the nineteenth century whose name is given to Broca’s area, the part of the frontal lobe involved in the generation of speech (which is wiped out in many stroke victims). Among his other interests, Broca used to measure brains, and he was always rather perturbed by the fact that the German brains came out a hundred grams heavier than French brains. So he decided that other factors, such as overall body weight, should also be taken into account when measuring brain size: this explained the larger Germanic brains to his satisfaction. But for his prominent work on how men have larger brains than women, he didn’t make any such adjustments. Whether by accident or by design, it’s a kludge.”

“Randomisation is not a new idea. It was first proposed in the seventeenth century by John Baptista van Helmont, a Belgian radical who challenged the academics of his day to test their treatments like blood-letting and purging (based on ‘theory’) against his own, which he said were based more on clinical experience: ‘Let us take out of the hospitals, out of the Camps, or from elsewhere, two hundred, or five hundred poor People, that have Fevers, Pleurisies, etc. Let us divide them into half, let us cast lots, that one half of them may fall to my share, and the other to yours … We shall see how many funerals both of us shall have.”

“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.”