How what you eat affects your mood, memory and thinking

David Benton

Penguin, London, 1996.

Should you buy vitamin supplements? Is chocolate bad for you? Are you allergic to some foods? These and many other questions are addressed in this excellent guide to a complex subject. It stands out amongst the thousands of diet and health handbooks for being a sober study of the psychology of nutrition.

The main lesson in the book is the sheer difficulty of establishing causal relationships:

"the powerful nature of the placebo response makes anecdotal comments or the response of a single individual a poor source of information. When one person claims that his or her problem has either been caused or cured by a change in diet, there is no way of knowing if anything other than a placebo response is involved".

This response has to be taken into account in drug tests, but the problem is harder for food research, in that double-blind tests may not be feasible: how can you remove fat from the diet without the subject noticing?

Then there is the question of individual differences:

"the need for a vitamin may differ by as much as several hundred per cent from one individual to another".

Can dietary supplements improve children's intelligence?

"Improved nutrition will bring no intellectual gain unless it takes place in a stimulating, emotionally secure environment. Even then the changes will take place gradually over a long period."

Might you be psychologically intolerant to certain foods? An interesting issue here is that although a particular food-stuff may have an effect, the belief that it does may also reflect another psychological problem.

"People, on the whole, are hostile to being described as suffering from psychiatric disorders. In contrast, the suggestion that an external agent such as food explains the problem offers a socially and psychologically acceptable explanation."

Perhaps the answer is to make sure that you have a more natural diet. But this is not as straightforward as it might seem:

"The word 'natural' has been hijacked by the food industry and used in a way that amounts to a confidence trick. A chemical is a chemical; it matters not at all if it was produced by a plant or in a chemist's test tube... The idea that everything natural is wholesome and good for you is obvious nonsense: some of the most potent poisons known are derived from plants. In all cases, both natural and synthetic chemicals must be monitored for their possible adverse actions."

(See Coward for more thoughts on "the natural".)

What's to be done, after all? (Musicians may find point 3 disturbing.)

  1. eat a varied diet, starting the day with breakfast, followed by small, regular meals
  2. eat more fibre, including 5 or 6 servings of fruit and vegetables per day
  3. consume less sugar and alcohol, and eat more wholemeal bread, pasta, brown rice
  4. consume less fat, especially saturated fat, but eat more oily fish
  5. drink 6 to 8 glasses of water per day (not mentioned by Benton)

Bon appetit!

"Here remark, that his dinner was sober and thrifty, for he did then eat only to prevent the gnawings of his stomach, but his supper was copious and large, for he took then as much as was fit to maintain and nourish him; which, indeed, is the true diet prescribed by the art of good and sound physic, although a rabble of loggerheaded physicians, nuzzeled in the brabbling shop of sophisters, counsel the contrary."

Rabelais, Gargantua and Pantagruel, 1, 23



Paul Taylor 2001