Seventy years of industrial farming have so severely depleted the soil microbiome that many soils are predominantly dead. Only by changing our farming practices can we rebuild its microbiological life and the soil carbon it depends upon.
Quite rightly, more and more doctors and members of the public are asking "what should I eat to stay healthy?"
As someone who has been farming sustainably in West Wales for the last 40 years, I would add the question "how should we farm so that the food produced truly promotes the health of the public?"
These two questions are linked, because what we have done to the chronic diseases of our bodies has very much been mirrored in the soil.
At our recent conference in San Francisco called 'The True Cost of American Food', Tyler Norris from Kaiser Permanente (perhaps the leading health insurance and managed health care company on the West Coast) said they are facing an unaffordable health treatment crisis. He attributed much of this to the industrialisation of agriculture, particularly in California's Central Valley which is America's 'food basket'.
Not that Norris knew, but he was echoing an observation made many years ago by Lady Eve Balfour who founded the Soil Association. She called for a thorough investigation of the causes of health (which she believed are rooted in the food we eat and the way we farm) because she saw the NHS becoming a "national disease treatment service" rather than a "national health service".
Lady Balfour had been inspired by Sir Albert Howard, a man who had been sent out to India at the height of the Empire, a century ago by the British Government, to encourage the people of India to adopt western diets. Fortunately, Howard had the intelligence and humility to realise early on in his mission that he had nothing much to teach India about sound nutrition.
He recognised too that the relative healthiness of North West India was due not simply to what people ate, but to the way their food was grown in soils which produced highly nourishing crops because the farmers, perhaps intuitively and without the science which has only recently confirmed its importance, always looked after the soil microbiome.
How much does current farming practice affect the health of the microscopic life of the soil? Ought farmers to try and influence it for the better, and do we need to change agricultural practice in order to restore the public health? To answer these questions we must go back 70 years and see what happened to post-war agriculture and farming.
In the mid-1940s this country embarked on an 'experiment' to stimulate the growth of plants and animals artificially. In the case of plants we used chemical fertilisers; with animals it was high protein feeds. The side-effects of these methods in the plant world include fungal diseases, pests and weed problems. Our response of course has been to suppress them with fungicides, pesticides and herbicides. (You might consider whether this process has parallels in medicine.)
Where livestock is concerned, high protein feeds disturb their internal microbiome. We then treat the ensuing infections and inflammatory diseases with a range of antibiotics and other antimicrobial drugs. The use of these chemicals in milk and meat production contributes to the development of antibiotic resistant bacteria and the crisis the world now faces, with the prospect of communicable diseases regaining their former power as the major cause of premature death globally.
Seventy years of this kind of farming has so severely depleted the soil microbiome that in most areas we now have a predominantly dead soil. Only by changing our farming practices can we rebuild its microbiological life and the soil carbon in which this resides.
This is well established. Less clear, until we have more research to go on, is whether in addition, pesticides are impacting on public health by contributing to endocrine dysfunction.
The damage done
Clearly the dying soil is already a huge and increasing problem. In parallel, we face a dramatic narrowing of the gene pool in agriculture and in the biodiversity that formerly co-existed on farmland.
A third element in the farming crisis, alongside these interwoven forms of depletion, is a pricing system that produces cheap food no matter what the true costs. But if farming methods had to take into account the damage done to public health and the environment, much would have to change.
When the cheapest food is probably doing you most damage, the food industry is sending very confusing signals to their consumers. Yet as long as the 'externalities' - the damaging consequence to public health and the environment - are not reflected in the price of food, good and sustainable food will always cost more at the checkout.
Farmers are in a bind too because there is a better business case for producing food in an intensive way than for producing food in a sustainable way, because they do not have to pay for the hidden costs. And so the system is perpetuated by a systemic problem in which farming has played a major role but is powerless to resolve.
The issue of endocrine disruption, due to pesticides and other chemicals routinely used in almost all of our food production systems, should also be of greater concern. Though there is an absence of solid data confirming or refuting the links between endocrine disrupting pesticides and negative public health outcomes, there are correlations we should not ignore.
One example of this is the herbicide glyphosate, easily the most widely used herbicide in the world, which for the last 40 years has been promoted as an entirely safe chemical. Last year the WHO classified it as a probable carcinogen due to its endocrine disrupting properties and studies indicating a link between exposure and certain types of cancer.
So if we are hoping to impact cancer prevalence by giving patients more health-promoting foods, we need to know whether those same foods carry other risks.
GMOs, glyphosate and the wrong sort of meat
I remain extremely concerned about GM technology, in part because of the risks we take by altering the natural world before we fully understand it, but also because it has resulted in other changes, including impacts on wildlife and the widespread use of Roundup, the most widely used herbicide containing glyphosate.
Glyphosate is getting everywhere. It is in air we breathe, the water we drink and, of course, in our food, partly because it is also used as a pre-harvest desiccant - in other words it is sprayed onto many crops like oil seed rape, both GM and non-GM and grain crops before they are harvested and thereby kills off all the plants in that field, so contributing to the dramatic narrowing of the gene pool.
Moreover, due to the uptake of GM crops farmers are increasingly rejecting the crop varieties that have adapted to the places where they have been grown for generations, in favour of GM herbicide or pesticide-tolerant crops.
This gives a farmer a short term economic advantage, but at a long-term cost that should make us all much more worried about trade agreements and pricing policies that will make it ever more difficult to stop the consequences of genetically modified crops affecting our food and our food supply.
As for the dangers of meat, I think we need to differentiate between grass-fed meat which is high in omega-3 fatty acids and antioxidants and grain-fed meat which contains very little of these vital nutrients. We also need to distinguish processed meat, which can include a wide range of chemical additives, and carcass meat from healthy animals.
When I went to Northern Kenya about 3 years ago, to a gathering of 26 tribes of 'nomadic pastoralists' I learned that most of them for much of the year were subsisting on a diet of blood, fresh meat and milk. They looked unbelievably healthy!
Perhaps with so many nutritional orthodoxies - notably the longstanding case against saturated fats, already now in question - we should at least keep an open mind about whether a health promoting and sustainable diet should include meat.
Better food policy
Right now there may be a growing (and changing) consensus on what is good for our hearts, our brains and our whole body and therefore what we should eat.
But we are a very long way indeed from having farming procedures and practices that would sustain that sort of food supply. And we won't make the necessary progress until growers properly engage with the health professionals who are responsible for maintaining public health. Only if there is public pressure will these things happen. I believe that if we could get public health and farming out of their silos and find a way of linking these sectors we could then make the necessary structural changes to agriculture.
We need to move away from chemistry to biology in the way that we farm. Nitrogen fertilisers are one of the principal reasons why the soil biology has diminished, along with the pesticides, which go hand in hand with them.
But giving them up would call not just for huge structural changes in agricultural systems, but also for a shift in what farmers produce, if 21st century diets are ever going to restore the vitality and the diversity of our farming systems and our population. Without fertiliser nitrogen, a return to the rotational practices of mixed farming is the only way we can rebuild soil fertility and produce enough nitrogen naturally grow bountiful crops.
This would be the biggest structural change in agriculture for more than half a century, and it would have huge implications for what we produce and provides another dimension to the whole issue of what we should eat. At the moment we have a globalised food economy. But surely within the constraints of our population and the capacity of our agriculture, we could produce much more of our food nearer home.
What would happen if we sourced our staple foods from the sorts of production systems that we are capable of switching to in this country, and if the national diet became fit to maintain public health?
Farming, food and the future
Above all we must link our diets with the productive capacity of a sustainable food system. In terms of our staple foods, a sustainable farming system would have to give up producing chicken and pork intensively.
We cannot rebuild soil health while growing arable crops year after year, as we do at the moment in many parts of the UK. And we should not continue to rely on imports of soyabean meal from South America where its production is degrading soils and rivers, while putting carbon into the atmosphere.
This would mean that we would produce less cereals, probably about half the quantity under a reformed agricultural structure. But during the fertility building phase which would probably be cellulose-based from grass and clover, we would need ruminant livestock producing red meat - grass-fed of course - to digest the cellulose, and also to re-manure and reinstate the lost biology of the soil.
And to give the farmers an income, we would need to eat that red meat. A sustainable diet should mean no more cheap industrialised chicken or pork, whatsoever. Some expensive grass- and partly grain-fed chicken and pork, because they can get some of their diet from grass, but probably no more than 30% since they cannot digest cellulose in the ways cattle and sheep can. We would still have to feed some grain to our dairy cows, as most dairy farmers do.
Salads would feature too but not the sort the supermarkets are selling. Unless you buy organically, supermarket salads are almost universally from hydroponics: not soil fed, but tube fed, and some studies suggest hydroponic produce impacts the human biome. We will need vegetables and some grain, but we would eat the grain instead of feeding it to intensively reared livestock.
For our health's sake we need to avoid processed foods. On the whole we need to move towards more fermented products - sourdough bread, yoghurt, cheese (lots of cheese - I am as you might suspect a cheese producer!).
To enable those changes, we need a massive education programme. It's no good just asking "what should I eat?" without linking the question to "how can we farm to produce health?", promoting food from farming systems ever more aligned to our new knowledge of microbiomes in the gut and in the soil.
For the soil is the gut - the source of nourishment - for the plants we farmers grow. And it now seems there is a vital link between the microbiome of our intestines and the microbiome of the soil. Seventy years of intensive farming have decreased the microbiome of the soil to such low levels that now we urgently need to restore it. And this will mean changing the way we farm.
To achieve this we need enabling policies and a supportive economic environment. The economic case will depend on finding a reliable means for assessing the negative health outcomes of present farming systems. Once monetised, we would have a very strong case for Government incentives to switch to more sustainable farming systems.
But as the health outcomes are going to be long term and certainly not within the political cycle, these changes will only happen if there is a huge rise in public awareness of the links between our health, what we eat, and how we farm.
Patrick Holden is the founding director of the Sustainable Food Trust, working internationally to accelerate the transition towards more sustainable food systems. He is also Patron of the UK Biodynamic Association and was awarded the CBE for services to organic farming in 2005.
This article is the text of a lecture by Patrick Holden at the recent conference 'Food: A Forgotten Medicine'. A full write up of the conference will be published in the Autumn issue of the Journal of Holistic Healthcare at the end of September.