We Want Real Food
by Graham Harvey 256pp, Constable, £9.99
A teaspoonful of healthy soil contains over 5bn living organisms from some 10,000 different species. As well as the earthworms that eat many times their own weight in soil each day and the dung beetles that drag little balls of nutrient-rich animal droppings down shallow tunnels where plants' roots can tap them, there are thousands of species that are invisible to the naked eye. Biologists have known of their existence for over a century, although some have only been fully understood recently. Take the thread-like fungi or microrrhizae that form intricate links with plant roots: they feed on the sap of the plant but in return they increase a plant's ability to take up minerals from the soil, and thereby become good food for us. But it is reductionist chemistry rather than biology that has ruled our industrial agriculture for more than half a century.
Graham Harvey's second book is a timely reminder that we ignore the health of the soil at our peril. Chemical farming has subjected its vital microorganisms to a toxic barrage, and does its best to obliterate them. By depending on synthesised nitrate fertilisers, agribusiness has depleted the soil of the minerals it needs to grow healthy plants. Over the last 50 years, according to some analyses, vegetables in the UK have lost a quarter of their magnesium, more than a quarter of their iron and nearly half of their calcium. The result is impoverished food, sick animals, and a catalogue of degenerative human diseases. Our lack of physical activity has halved our need for calories, yet we still need the same amount of vitamins and minerals. That the nutrient content of our food should now be so depleted is therefore disastrous.
Harvey traces this "story of a national treasure lost" back through early 20th-century explorations of the links between diet and health. He follows a line from the brilliant 19th-century chemist Justus von Liebig, through German interwar chemical manufacturing to the postwar agrochemical industry. It was von Liebig who first showed that you could take any substance and by combusting it reduce it to its chemical components. He analysed the chemical constituents of the soil, explaining the role of nitrogen, phosphorus and potassium in the growth of plants, and thereby paving the way for artifical fertilisers made of those three elements.
In fact, in the mid-19th century the decline of the natural fertility of the soil was already a major concern (although this is beyond the scope of Harvey's book). Both Europe and America had started depending on imports of natural fertilisers and indulging in "guano imperialism" - the US seized nearly 100 islands and rocks around the world between 1856 and 1903 to secure its supplies of guano. And it was Karl Marx, drawing on von Liebig, who articulated the wider social implications of soil fertility. Writing in Das Kapital, he argued: "Capitalist production ... disturbs the metabolic interaction between man and the earth, it prevents the return to the soil of its constituent elements consumed by man in the form of food and clothing. All progress in capitalist agriculture is a progress in the art, not only of robbing the workers, but of robbing the soil."
Industrial agriculture, Harvey argues, looks at the effects of a single measure taken in isolation. In mainstream biology, this reductionist view has been largely discredited, but in farming it still holds sway. Agronomists still throw chemicals at crops and look for higher yields. Nitrogen fertilisers stimulate not nutrient density but excess growth of sappy tissue with thin cell walls. Fields are sown with a single species of grass, perennial ryegrass, in a monoculture that wreaks the structure of the soil and provides only "ruminant fast food". Animals fed this way or reared on intensively grown grain and soya do not get the nutrients they need, nor do they nourish us. Their meat and milk are low in the essential fats and minerals we need for good health. The irony is that traditional farming patterns, with their rotations of nitrogen-fixing crops, husbanding of species-rich meadows and use of composts and manures, adopted by instinct the same integrated approach as modern biology. But once the Germans had shown how to produce industrial quantities of ammonium sulphate, these were displaced by the so-called green revolution.
It all might have been so different. Harvey describes the work of early pioneers of nutrition and health. Robert McCarrison was a doctor in the Indian medical service during the early 1900s who served in what is now bin Laden country. He compared the diets of the people of the Hunza valley in the Karakorams, to those of the southern Indians and working class Britons. The Hunzakots were legendary for living to a great age and for being free of the diseases of industrial nations such as cancer, heart disease and tooth decay. The people of southern India suffered high rates of early mortality, the working class Britons high rates of disease. McCarrison fed rats the diets of the three different groups - the Hunza ate whole grains, no sugar or refined flour, and not much meat but lots of fruit and vegetables grown on highly mineralised soils irrigated by glacier-fed waters, notably the famous Hunza apricots. The southern Indians ate polished rice and meats while the poor Britons lived on white bread, marge, jam, tinned meat, potatoes and sweetened tea. The rats fed the Hunza diet lived longest while the others sickened.
Others were exploring the same territory of nutrition and health at the time. Weston A Price, a dentist from Ohio in the 1930s, was appalled by the effect of industrialised food on his patients' health and set off to study the traditional diets of remote peoples. He found that traditional diets produced physical perfection, with a wide bone structure and straight teeth, no orthodontists needed, while those who abandoned the food they had evolved with for processed foods were afflicted with disease and crooked teeth. In Perthshire, Dr Walter Yellowlees, working postwar as a GP, catalogued a rise in cancer, arthritis, rheumatism, respiratory diseases and tooth decay that paralleled the abandonment of traditional farming and its oats, kale, turnips and milk for industrial production of refined carbohydrates.
But medicine took a different path. Antibiotics arrived, and instead of disease prevention through nutrition, miracle cures and technical fixes became the preoccupation. It is only now with the crisis of obesity that the mainstream is recognising that it has to go back to the first links in the food chain.
Like Harvey's previous book, The Killing of the Countryside, We Want Real Food draws on a depth of knowledge to make fascinating connections. The only shame is that his publishers have felt the need to scatter the text with case studies in tinted boxes. The effect is a sort of fast food for readers, when this is a book that deserves to be properly chewed over.
· Felicity Lawrence's Not on the Label is published by Penguin. To order We Want Real Food for £9.99 with free UK p&p call 0870 836 0875.