by Michael Pollan Penguin Press, 2008 Review by Christian Perring on Jan 29th 2008
Michal Pollan argues that while modern science is getting better at measuring the nutrients in food, it still has very little idea how they relate to human health. He identifies the problem of nutritionism where we place far too much confidence in the meager knowledge of food science, and he suggests that this is a major cause of modern disease. He makes a plea for a return to traditional eating of whole foods and preparing meals from raw ingredients, and encourages readers to avoid processed foods and industrially created food. His argument is convincing.
We have little idea how food works in the body, yet in the last fifty years, there have been many fads and fashions in recommendations about what foods are best to eat. Despite all the food education we receive through modern media, Americans are getting more obese and suffer from heart disease, diabetes and cancer in far higher rates than people in non-western cultures. A trip around a modern supermarket shows shelves full of products making claims about their healthy properties, and Pollan finds this ironic, since the healthiest foods in the supermarket, the fruit and vegetables in the produce section, don't have health claims on them. Pollan suggests it is probably best to avoid food products that make health claims.
Pollan does not completely dismiss all food science, but he argues that we simply do not know enough about the hugely complex biology of the human body to make confident recommendations about what is good and bad for us. One of his main examples is the history of the modern horror of fatty foods. There were links between eating fat and heart disease, so nutritionists recommended cutting down on fat. Then corrections were made, with distinctions between saturated and unsaturated fats. Other distinctions between different kinds of fat have also been made. Now low fat food is manufactured and promoted. Yet Pollan argues that there is no proof that we know what causes our western diseases or that eating these low fat foods will improve our health, and the whole "low fat" fad has been based on poor science.
Food science and the investigation of nutrition is worth doing, of course, but we should be far more careful about what conclusions to draw from them. We do want to know the link between omega-3 fatty acids and our psychological health, for instance, but it would be a mistake to suppose that taking omega-3 capsules will be good for us. The whole mistake of nutritionism is to see foods as collections of individual nutrients. Unfortunately, we just don't know enough about how foods work in our body to make sound judgments about particular chemicals. Taking food supplements and following food fads is rarely good for us, and in some cases, such as the recommendation of giving up butter and eating margarine instead, health recommendations may have been bad for us.
While we don't have a good idea of the links between particular chemicals and health, we do have a good idea of what food habits are unhealthy. Eating lots of fast food is bad. Eating lots of processed food is bad. Eating a diet mostly from fresh vegetables is good. We would be much better off if we stopped eating a modern "western" diet and returned to the diet of our ancestors. Furthermore, we should go back to enjoying our food; growing it, preparing, and eating it with pleasure. This makes a great deal of sense, and Pollan makes a strong argument for it. He recognizes the difficulty that we may have in implementing this in our modern lifestyle, so he spends some time discussing how we can get back to a more sensible way of shopping and living. In Defense of Food should be required reading for those wanting to eat healthily.