“Nevertheless, there is a substantial and growing body of evidence to support the claim that nutrient content of intensively bred crops has dropped as yield has increased and time to harvest has decreased. Modern cultivars have been continuously selected for rapid growth and yield and, for the most part, have not been selected or even screened for nutrient content.”[i]
There is one last item to consider regarding a high-quality diet based on plants that supports our microbiome and that is the problem of finding high-quality plants. This problem has become perhaps my greatest concern. It does us little good to eat lots of plants if the plants are of low quality and, unfortunately, the products we’re being offered in the grocery store are on a rapid decline in that regard.
To be clear, I consider plant quality to be a measure of two things: cellulose and secondary compounds. Both of these, in turn, are products of a plant expressing its full genetic potential and that expression is only likely to occur under normal growing conditions and given a sufficient amount of time. We have come full circle to the introduction of this book where I used the tomato as an example to express this point but, in fact, the loss of quality applies to almost all foods that we currently eat.
Concerns about food quality have grown as the food production system has become ever more dependent on chemicals, pesticides, fertilizers, genetic modification, and advanced technology for enhancing growth and production. The number of books making claims about food and food production in relation to our health and the health of the surrounding ecosystem is hard to keep up with.[ii]
The loss of genetic variation in crop plants that leads to a loss in food quality has been a talking point since the 1950s; Reginald Painter at Kansas State University was among the first to suggest that the emphasis on breeding for particular strains of our crops was the wrong direction to take. His primary point was this: in crop fields where there was more genetic variation, the losses to insect pests was lower. He was concerned that breeding for crop uniformity, and therefore for low genetic variation, would lead to a loss of resistance and a greater reliance on pesticides. In his view, we should focus research on maintaining genetic variation and understanding how that could be used to produce more robust crops.
Instead of heeding Painter’s advice, the agricultural research world went rapidly in the other direction to focus on breeding for higher productivity, faster growth, more uniformity, and a predictably higher, much higher, reliance on technology. The loss of genetic potential in crops has reduced the capacity of those plants to express the full range of secondary compounds that are part of the species’ heritage. As a consequence, our plant foods are slowly losing their nutritional value.
Like a snowball rolling down a hill, agricultural technology was increasingly geared toward producing strains of crops with hugely increased productivity and much faster growth. Today, we not only marvel at the levels of productivity, but also the ingenious technological strategies for eliciting that productivity from the crops. Initially, the increase was due to artificial fertilizers, then to breeding programs for faster growing plants, but now an entire industry is devoted to manipulating the genetics of crops to grow indoors, without soil, with uniform taste and texture and predictability.
As consumers, we think nothing of this process because we have come to believe that we will always have technology to solve our food problems. But what if this IS the source of declining food quality? What if, as Klee and Tieman say at the top of this chapter, this kind of food is not as good as it used to be? What are the repercussions to our health?
When plants are grown under artificial or highly modified conditions, what happens to them? For starters, plants grown quickly put little cellulose into their tissues. The leaves are soft and do not have the toughness needed to survive ibn then outside world. This physical reinforcement occurs outdoors when the wind blows and the plants are forced to resist the wind.
When we buy pretty greenhouse plants, like small trees, for our yard that have been living a life of luxury in a protected environment with unlimited resources, they must be staked up or the wind will blow them over. After a year or so of living outside, the plants can manage for themselves because the feedback from the environment has caused them to invest more in strong stems. UV radiation from the sun will cause leaves to become sturdier as well. The leaves of greenhouse plants often burn when planted in full sun and those leaves will be replaced with newer, tougher leaves.
Plants living outside the greenhouse are forced to invest more in important structural parts, such as roots, stems, and leaves, whereas that investment was not necessary for growing in an environment that was shielded from nature. Unfortunately, greenhouse businesses that grow peppers and tomatoes are not interested in roots, stems, and leaves; they want fruit. Growers are not interested in plants that divert energy to stems when that energy could be diverted to making more fruit. And so, the crop breeders produce strains of peppers and tomatoes that divert energy to fruit and less energy to strong rigid stems. And they have produced plants that can tolerate, perhaps even require, the greenhouse environment.
In modern greenhouse and hothouse operations, there is little to no actual soil. If any soil is used, it is more or less sterile in the sense that normal bacteria, fungi, and nematodes are not present. Actual inorganic components such as sand, silt, and clay are not present either; the soil is an artificial “growth medium”. All nutrients are delivered to the plant in the irrigation water as are most of the systemic pesticides. The air around the plants moves at a constant speed because of electric fans; heaters and coolers are used to maintain optimal and uniform temperatures. Light intensity is adjusted with artificial lights and any sunlight is indirect because of the indoor conditions.
In the greenhouse, there are no insects allowed unless bees, for example, are brought in specifically for pollinating flowers. Chemical use is frequent, if not constant, because of the threat of invasive pests such as aphids, white flies, spider mites, and a number of other tiny nuisances. And the plants grow extraordinarily fast and large because not only is less energy is being diverted to structure (the plants are physically supported), the plants divert little to no energy to defenses against insects. The conditions are ideal, the stresses are minimized, and the plants are factory-style production units. This is how you get a modern tomato.
This approach to food production can be applied to any annual plant and some perennial plants. In the produce section of literally all major grocery stores, you will find strawberries, blackberries, tomatoes, melons, zucchini, cucumbers, broccoli, celery, parsley, herbs, and many more, and at any time of year. Depending on where you live in this world, all or nearly all of these plants may have been grown indoors.
With the application of high-tech equipment, it just isn’t cost-effective to grow these kinds of foods in uncontrolled outdoor environments where the watering, feeding, trimming, and harvesting processes are not completely uniform and the losses to pests and weather can be highly unpredictable. Farms that are trying to produce food in the old-fashioned way are quickly going out of business unless they can market their produce through local stores, farmer’s markets, or restaurants. But even so, they will be producing and selling a fraction of the quantity of the commercial, factory-style systems.
The result of an emphasis on productivity and speed is physically weak plants that disperse all available energy among a much larger number of fruits that is normal for the type of plant. Those fruits are harvested well before they are truly ripe and before the plant has an opportunity (if it even possesses the ability) to invest secondary chemicals, such as defense compounds, antioxidants, flavors, and vitamins that give the fruit its natural qualities.
Obviously, taste is one of those qualities of our crop plants, but taste is derived from the mixture of the many chemicals the plants produce, many of which are occur late in the ripening process, and many of those are why we enjoy eating the particular plant. That is, the subtle health benefits of plants as slow medicine are found in the complete plant, not the strange, inbred, genetically incomplete plant that now adorns the shelves of the produce section at the grocery store.
The quality is being bred out of the plants and we should care. We are what we eat and we want to eat real food because our microbiome is also what we eat and it needs real tomatoes.
If establishing a diverse microbiome at birth is important, then no less important is maintaining that diversity for the rest of one’s life. This maintenance can only be done through the consumption of diverse foods containing slow-to-digest materials and most of this comes from unprocessed plants. A major component of shepherding a diverse microbiome as one ages is being able to avoid or recover from events, such as antibiotics, that damage the microbiome.
Unfortunately, coincident with the development of antibiotics after 1945 has been the inexorable development and adoption of a modern diet, usually called The Western Diet. We can also call this the PFC Diet: high in carbs, fats, sugars, and processed grains, low in fiber content, and in which fresh fruits and vegetables are a small percentage of the total.
The diet of Americans, for example, has gained 500 calories in the past few decades just from sugary drinks and this was a result of the development of high fructose corn syrup. A technological breakthrough in 1980 created a rapid and inexpensive way to produce corn syrup and immediately the cost of sweeteners for many different foods and drinks dropped dramatically. Selling sugary drinks became a huge money maker in the US and around the world because the syrups were no longer the limiting factor in sodas. And we began to consume huge amounts of what my mother called “empty calories”; that is, calories that did nothing to reduce my youthful appetite, but which I found delightful. An increase of 500 calories per day over basal metabolic needs equates to weight gain of about one pound per week.[iii]
It is weird to think that the combination of an ever-lower quality diet and the frequent use of antibiotics has forced us to think of the maintenance of a healthy microbiome as an intentional act instead of a natural process. Historically, we never had to wonder if the food we were eating was good for us and now everything at the store requires scrutiny of the nutritional contents by the conscientious consumer. Of course, we have to worry that anything new might actually be bad for us, but is it right that we have to be concerned about foods that have always been the definition of “good food”?
[i] Klee, H.J. and Tieman, D.M., 2013. Genetic challenges of flavor improvement in tomato. Trends in Genetics, 29:257-262. [ii] Examples: Insect resistance in crop plants (Reginald Painter, 1951, Kansas Sate); Chasing the Red Queen (Andy Dyer, 2014, Island Press); Food, Genes, and Culture (Gary Paul Nabhan, 2013, Island Press); The Omnivore’s Dilemma (Michael Pollan, 2006, Penguin); Diet for a Dead Planet (Christopher Cook, 2006, The New Press). [iii] FOOD MATH: One pound equals 16 ounces, an ounce equals 28.3 grams, and there are 9 calories per gram of fat. Thus, one pound of fat equals ~4000 calories. To lose one pound of fat, one must burn about 4000 calories over and above what one consumes. If the standard diet is 2000 calories per day, one could try not eating for two days to lose a pound OR one could reduce food intact by 500 calories for 8 days. Unless one is over-weight by hundreds of pounds, losing weight fast is not easy (or healthy), and losing weight slowly is frustrating and requires determination. To begin, if one stopped consuming empty calories, such as the 500 sugar calories the average American drinks each day, losing a pound a week could be possible without even exercising.