To have healthy food we need to start with healthy soil. This book is a call to be part of the regenerative farming movement that includes successful practical, cost-effective ways to care for the soil-and-food aspect of our lives.
What Your Food Ate is well-researched, convincing, very readable, well-written and lively. It is a book to read carefully, in small bites: rich, nutritious and very filling. Your brain will need time to digest each chapter. A book to come back to repeatedly, to top up your learning and check your beliefs.
Dave is a geologist, Anne a biologist. They re-examine beliefs about health, medicine, our bodies, our food and our farming, showing how regenerative farming can heal the soil, restore the land and grow nutrient-dense, flavor-packed food, helping us towards better health. The health of the pasture influences the health of the livestock. And the health of our food influences our own health. Hence the title of this book, What Your Food Ate.
The food we buy today is a lot less nutritious than that our grandparents ate as children. You need to eat several of today’s apples to keep the doctor away! When food production follows short-sighted goals, water and air pollution, climate chaos, and bad working conditions for farm laborers all prevent optimal general health and well-being.
Desires for easily obtained (“cheap”) food, sufficient for everyone (if fairly distributed) led some to believe bigger was better, and more was better still, with a focus on calories rather than quality. Nowadays, over two-thirds of Americans are overweight, and obesity-related illnesses account for 20% of healthcare spending. The percentage of income spent on food fell by half since the 1950s, but the cost to society of healthcare more than doubled. It has become more profitable to treat chronic diseases than to prevent or cure them in the first place. How food is grown affects human health. Cheap food has high costs!
In the past century we have switched from eating mostly minimally processed plant foods and some meat, to more than half the calories filling up North Americans now coming from ultra-processed foods. Many chronic diseases and auto-immune disorders arise from inflammation
In good soil, plants take in what they need of both macro- and micro-nutrients. Disruption caused by the agronomic trinity of mechanized tillage, agrochemicals and monocultures leads to weaker plants and less nutritious food. Industrial fertilizers tend to contain only macronutrients. These do spur growth, especially in poor soils. But plants (and animals) need micronutrients too.
How do plants eat? Photosynthesis fuels plant growth by combining water with carbon dioxide. The soluble part of the humus in the soil is drawn up in water by the roots, growing the plant. This discovery led to the temptation to supply soluble chemicals directly to the soil to boost growth (hydroponics).
How do insoluble minerals move from the soil into the plants and animals that become our food? Rocks and soil supply the elements that don’t come from air or water, via the bodies of microbes (bacteria and fungi, including mycorrhizal fungi that coat the roots of some crops), cycling them around. For those seeking a concise understandable description of plant nutrition, photosynthesis and soil microbes, you’ll find it here.
Carbon makes up half of the soil organic matter; plants actively recruit and support communities of microbes that promote their well-being. A 1994 study showed that tropical soils could only be tilled profitably for less than ten years, after which the organic matter had been used up. Temperate prairie soils typically survive for just over 50 years of tillage before wearing out. Starving soil microbes in the pursuit of quantity cannot provide quality crops.
USDA agronomists found significant declines in iron, zinc, and selenium in wheat varieties from 1873 to 1995. When high-yielding Green Revolution varieties were introduced they unintentionally decreased mineral density. Breeding for larger size causes the nutrients to be diluted to fill the larger product. But ignoring nutrient density, we are feeding many people a relatively empty diet, leading to obesity and chronic illness. In the same world, other people have insufficient calories and chronic micronutrient deficiencies.
In England, the Broadbalk Wheat Experiment started in 1843 to test the effects of various chemical fertilizers and organic manures on yields. Concentrations of four minerals in the wheat remained stable until about 1960 than decreased significantly every year after that, despite there being no decline in the mineral levels in the soil.
A wheat farmer in Oregon grew two adjacent fields of the same crops, under two different methods of weed control. One was the conventional method of continuous winter wheat with applications of glyphosate. The other was a complex rotation of spring barley, winter wheat and a cover crop mix. The purpose was to determine if keeping the fields vegetated year-round would outcompete the weeds and make glyphosate unnecessary. After two years both fields produced 75 bushels an acre. The wheat from the cover-cropped field had 35%-56% more boron, manganese, and zinc, and 18%-29% more copper, iron and magnesium, without any supplemental minerals. Trillions of microbes were ferrying the minerals to the crop.
Suspicion that farming practices, soil health, nutrient density and human health were declining had been a concern in England since 1939. A 1936 study found two-thirds of children had major dental problems. For comparison, the English population of Tristan da Cunha, an island in the south Atlantic, had perfect teeth. The agricultural methods were to blame. It is now thought that exposure to soil and its microbes, fungi and bacteria early in life protects against asthma and allergies. A troubling question has been whether we can feed the world while also nurturing soil life and building fertility. It might be thought that the decline in nutrient content could be offset by eating more, but that is not so.
Although nitrogen is nitrogen regardless of the source, there are differences in what else (if anything) is delivered with the nitrogen. Synthetic nitrogen can stimulate microbial activity, causing organic matter to break down quickly. Corn, wheat and rice all take up more nitrogen from the soil organic matter than directly from applied chemical fertilizers.
A 2017 analysis of 56 studies globally paired organically farmed and “conventionally” farmed fields with the same soil type, for 16 years. Organically farmed soils held almost 50% more carbon and nitrogen, with more microbial diversity than the conventionally farmed soils.
When farmers in the 1990s took a shortcut to dealing with weeds using glyphosate, they found that glyphosate-resistant GM corn, cotton or soybean yields did not grow bigger than non-GM crops despite the lack of weeds. And by 2012, almost 50% of farmers had glyphosate-resistant weeds in their fields.
Glyphosate was marketed in 1964 for cleaning corroding pipes. Next it was marketed as an antibiotic. Consuming antibiotic-laced food messes with our gut microbiota. Roughly 40% of the molecules in our bodies come directly or indirectly from our gut micro-biota.
In the soil, glyphosate binds to minerals, substantially reducing uptake of copper, zinc, manganese, iron and calcium, making them almost unavailable to plants and microbes. After glyphosate use, neither crop plants nor weeds are able to make several essential amino acids. Glyphosate damages the mitochondria of some plant and animal cells (but apparently not mammals). Beneficial microbes suffer from being dosed with an antibiotic, leaving plants vulnerable to pathogenic fungi such as root rots, and the consequent stunting of growth. In the 1990s, 24 diseases in 14 crops were found to have increased with glyphosate use.
Modern processing strips important nutrients from our staple grains. It has long been known that white rice causes deficiencies leading to beriberi. A 2010 study showed that eating white rice five or more times a week increases the chance of diabetes by 20%. Eating brown rice twice a week or more decreased the chance of diabetes by 10% compared to eating it only once a month.
During the Second World War, people in the UK switched to being more food self-sufficient. Public health improved during the war years, as people were encouraged to “Dig for Victory”; dietary education was widespread; sugar imports were cut while those of cheese, fish and dried pulses were increased; wartime bread was made with less-refined flour; and food was rationed (meaning rich and poor got more equal access). The health of the nation improved.
After the war, nitrogen fertilizer was promoted, using factories where nitrogen had been made into explosives. High levels of nitrogen in our food and water react with amines in our stomachs, forming nitrosamines, associated with cancer of the stomach, bladder, and in men, the prostate, in women, the ovaries. Colorectal cancer and thyroid disease, as well as birth defects, are connected with high nitrate levels in drinking water. Minerals and vitamins are adversely affected by high nitrate levels. Consuming fresh vegetables and fruit provides something of a protective effect.
When the USDA decided to include hydroponic food production as Organic, many farmers pointed to the wording in the Standards requiring good soil health practices, and formed the Real Organic Project. Hydroponic growers choose what to put in the water they cycle through the roots of their crops. When profitability and not health is the highest value, they add the NPK and not the micronutrients.
Relying on chemical fertilizers increases the demand for pesticides; higher pesticide use compromises plants’ ability to defend against soilborne pathogens. Soils farmed organically have a higher abundance of mycorrhizal fungi, likely contributing to disease suppression. Soil building practices improve soil health, crop health and human health. Microbes from compost provide huge benefits to the soil, even when the compost is spread only thinly. They boost the abundance and activity around the crop roots and suppress pathogens.
Farming practices that promote mycorrhizae and increase the beneficial bacteria will increase the mineral and phytochemical content of the crops, making them healthier, more resilient and more productive. People eating those crops have the phytochemicals they need to enjoy good health. Just a month on a phytochemical-rich diet (whole grains, nuts, at least six servings of vegetables and fruits daily) reduce cholesterol levels by around 15% and increase antioxidant activity by 1/3-2/3. Consuming half a clove of garlic a day can reduce cholesterol levels by 10% - I’m not sure how long that regimen lasted.
Of 100 preschool children in Seattle, 99 had measurable amounts of at least one pesticide residue. Almost 75 had two or more. Those in households where pesticides were used in the garden had higher levels than those that did not use pesticides. Tests on 1,000 adults in the US found pesticide residues in all but 20 people, indicating widespread contamination. Levels varied one-hundred-fold. Changing to an organic diet can decrease levels within a week.
Pesticides have effects beyond the target plant. Acute exposure is most dangerous, but chronic exposure from inhalation, skin exposure, food and water can all take a toll over time. Falling human fertility rates have been linked to pesticides. Prenatal exposure has been linked to developmental problems in the first two years of life. Childhood exposure increases the odds of ADHD and other neurobehavioral problems as well as leukemia and non-Hodgkin lymphoma. Farmers, with a higher-than-average exposure to glyphosate, have higher rates of lymphatic cancers. Pesticide residues are also associated with many gastrointestinal, neurological, respiratory and reproductive effects, Parkinson’s disease and endocrine disorders.
Over the past century our growing use of pesticides has killed off almost half of the world’s insects, and large numbers of grassland birds. Among conventional agronomists glyphosate is generally regarded as safe because it has low acute toxicity and it was believed to break down rapidly in the soil. More recently, concern has increased, partly because glyphosate seems to be everywhere.
Particularly virulent poultry pathogens (Salmonella and Clostridium) are highly resistant to glyphosate, while beneficial bacteria are killed. Glyphosate is toxic to lactic-acid bacteria that usually control Clostridium botulinum in cattle. Ingestion of glyphosate-contaminated feed could undermine the balance in the gut of the cattle and predispose them to disease.
Some phytochemicals, such as glucosinolates, control soilborne pests, including fungi, bacteria, insects and invertebrates. Healthy soil helps plants resist pests and pathogens, and reduces the need for pesticides. Pests rebound faster than their predators, so the pests rebound in sprayed fields which soon have as many pests as unsprayed fields. Unsprayed fields have more predators, and no sprays. Composted plant debris and manure decrease the number of pathogens. Crop rotations can reduce soybean aphid populations to just 25% of prior levels.
The chapter on dairy production is entertaining and illuminating. A cow’s rumen may hold 50 gallons of fermenting forage and trillions of microbes. The bodies of the bacteria provide protein to the cow, who converts them into meat and milk. Our stomachs are very acidic and do not digest by fermentation but by dissolving our food. Very different.
In fermenting the cow’s feed, the microbiota in the rumen produce two main by-products: gases and fatty acids. Fatty acids combine to make fats, many of which are essential and valuable, such as those that build cell membranes, feed brains and eyes, and contribute to milk. The balance and composition of fats (and phytonutrients) in milk depends on the type and quality of the plants the cows eat.
Today most US cows live indoors eating carbohydrate-rich foods, mostly corn and soy. Their milk contains less milk-fat and more saturated fats than pastured cows. Their butter and cheese are not as nutritious or flavorsome. The phytochemicals with antioxidant, anti-inflammatory and antitumor effects are in much lower levels in concentrate-fed cows, and their meat is not as good either. Since 1945, death from heart attacks have been associated with eating lots of animal fats, and with cholesterol in particular. The data pointed that way, but other factors, such as unsaturated fats, were overlooked.
The countries with the highest rates of heart attacks and fat consumption also consume the most sugar and omega-6-rich oils from seeds. In a study, Japan and Italy had the lowest rates of fat consumption and heart attacks, with low consumption of omega-6s but lots of other fats, such as omega-3s from fish (Japan) and omega-9s from olive oil (Italy). An ignored Minnesota study from 1968-1973 found that replacing animal fats with omega-6-rich vegetable oils lowered cholesterol but increased death from heart disease.
A balance of omega-6 and omega-3 fats helps the immune system to manage inflammation. The typical American diet today has 10-20 times more omega-6s than omega-3s, 3-5 times higher than what is thought best for health. Chronic inflammation in the arteries is a big risk factor for high blood pressure, heart attacks, and other indicators of cardiovascular disease.
We have been encouraged to think that fish is healthier food than beef, but it depends on what your food ate. Much fish eaten in the US is farmed, kept in pens and fed manufactured feedstocks. They tend to have high ratios of omega-6s to omega-3s. Fully pasture-raised beef can be better!
Chicken is no longer a low-fat alternative to beef. Many chickens today have 5-10 times more fat than those in the late nineteenth century. The ratio of omega-6s to omega-3s has increased a lot.
Half of the cattle in feedlots die of bovine respiratory disease, a non-contagious chronic disease that compromises overall health. Antibiotics are commonly administered as a preventative measure, but these can lead to other problems. Rotational grazing provides ruminants with the best quality forage, and they are experts on choosing which specific items to eat that day based on their needs. Humans also have subconscious body wisdom, and choose particular foods at different times, when they can. Ultra-processed food products have manufactured sweet, salty, umami and oleogustus (fat) flavors added to make them more palatable.
Receptors in the gut pass on info that sets other processes in motion, like the endocrine cells in the gut that adjust the release of insulin to match food intake. Bitter taste receptors nudge us to choose bitter foods which help us deal with some respiratory infections, potentially decreasing the need for antibiotics. Several common bitter dietary phytochemicals, especially kaempferol, resveratrol and quercetin, help knock back coronaviruses, including Covid-19.
A study comparing what people ate on an ultra-processed diet and an unprocessed foods diet found that the ultra-processed diet led people to eat well beyond when they were full and gain about one pound of weight per week. The rush to low-fat diets (without distinguishing between different types of fats) led to Americans eating more low-fiber carbs and gaining lots of weight, as the carbohydrates turned into fats in the body. More bad advice was to choose lean over fatty meat, leading people to consume more processed meats with lots of salt and additives like nitrates.
Diet-related chronic diseases surged in wealthy countries in the twentieth century, and dietary advice swung back and forth. The gut microbiome influences how many calories a person can extract from their food, and weight regulation is not simply balancing calories in with calories out. Low-fat diets lower the level of “good” HDL cholesterol, especially in women, and triglycerides go up. The 1990s Boeing study showed no evidence that saturated fat in the diet led to increased risk of heart disease or fatal heart attacks. 30 years previously the Food and Nutrition Board of the National Academy of Sciences came to much the same conclusion. That was opposite to the newly released US Dietary Guidelines.
The book includes studies about milk, inflammation, healthcare, the balance of omega-3s and omega-6s, whole grains, vitamin deficiencies, and encouragement to support regenerative farming practices, which restore soil health, allowing production of abundant, diverse, nutrient-dense crops.