Authors: T. Colin Campbell
I hope I’m being clear that I’m not advocating a return to faith-based dogmatic acceptance of any authority’s views on reality. To the contrary, I’m asserting that we need less dogma and more open-mindedness in the scientific community when it comes to observing and describing our world. One of the core principles of science—the key element that distinguishes it from every other way of looking at the world—is the idea of falsifiability. Basically, if a theory is falsifiable, that means that evidence can be offered to disprove it. The opposite stance, dogma, is, by definition, anything that is considered unfalsifiable.
Let’s say you believe that the bus from New York City to Ithaca always arrives on time. You would agree, I assume, that if it pulled into the station twenty minutes late one day, that would prove your theory false. You might then amend your theory to “95 percent of the time,” or to “within half an hour of its scheduled arrival time,” and we could agree on observations and experiments that might support or contradict those new theories. But the key point is, you accept in advance that some configuration of observable facts could partially or completely invalidate your theory.
Contrast that with belief in an afterlife in which the good are rewarded and the evil are punished. If you ask those who believe in this brand of an afterlife what evidence would cause them to reconsider that belief, they are most likely to stare at you in confusion. Such faith is not open to factual contradiction. Even if you don’t believe in such an afterlife, can you think of any facts that we could gather that might invalidate it? I’m not saying such a belief is right or wrong, just that it’s not science because it can’t be disproved, or falsified, by observation or experimentation.
The reductionist paradigm is dogma, an article of faith; it rejects, beforehand, the idea that it may not always be the best or only way to apprehend and measure reality. And modern science (and the biological and health sciences in particular) has embraced the dogma of reductionism to the exclusion of common sense and fairness. The most respected
and learned individuals in our society are trained to operate exclusively within the confines of this dogma. To return to an earlier metaphor: these individuals spend their time studying and writing about the minutiae of elephants without a single one of them being aware that there is such a thing as an elephant. The tragedy is, this is the system we have entrusted with the search for truth, whose findings determine our public policy and influence our private choices.
Reductionism Invades Nutrition
The first problem for all of us, men and women, is not to learn but to unlearn.
—
GLORIA STEINEM
N
ow that we understand the fundamental flaws of the reductionist paradigm in general, it’s time to explore how this paradigm has distorted and degraded nutrition and human health.
I know food and nutrition aren’t considered to be very important outside my little world. The newspapers I read have sections on politics, business, sports, and entertainment, but none of them devotes a daily section to food policy. Food writers are restaurant critics or purveyors of recipes, relegated to the same pages of the newspaper devoted to hairstyles, fashion, and home decor. But food is pretty much the most important topic there is. No food, no civilization. Crop failures, outbreaks of mad cow disease, and contaminated produce could bring our society to its knees very quickly. We assume we’re immune to such catastrophes because
most of us think about food as the stuff we buy at the supermarket. And every time we go to the supermarket, guess what? It’s overflowing with food. We aren’t going hungry, so everything must be fine.
But just because we don’t think about our food all the time doesn’t mean it’s not critically important. Most of us don’t obsess over our oxygen supply, but people who find themselves submerged in water or trapped in a smoky building can think of nothing else. Food is as fundamental to our survival as oxygen. But while we all breathe the same air, we have lots of choices when it comes to food, and those choices determine not just how we eat, but also how we utilize our agricultural land, what our government subsidizes, what we teach our children, and what sort of society we create.
In the same supermarket, we can choose to fill our carts from the produce section, the dairy case, the meat freezer, the canned goods aisle, or the packaged-goods aisle. We can get our produce from local growers or from giant factory farms in South America. We can eat out at fast-food restaurants or cook in our own kitchens. And when our choices cause us to gain unacceptable amounts of weight, we can adopt any one of a thousand different diet plans, from Atkins to Paleo to Weight Watchers to macrobiotic. All these individual choices add up to affect our national food “system,” just as the food system itself strongly influences those individual choices. Both the system and our personal choices have been heavily driven by our beliefs about nutrition.
If they weren’t, would such a large percentage of food packaging be taken up by nutritional labels? Why else would the federal government spend so much money and time creating food groups, food pyramids, recommended daily allowances, and daily minimum requirements? Why else would the FDA create and enforce rules about what food, drug, and supplement manufacturers are allowed to claim as health benefits?
So although it doesn’t make the news very often, food, and our national policies about it, determine a great deal about our society. And nearly everything our society believes about nutrition has reductionist fingerprints all over it. In this chapter, we’ll explore how the reductionist paradigm has led to poor nutritional policy and confused consumers, as well as how and why nutrition resists the reductionist model our society works hard to put it in.
The definition of the word
nutrition
is something I’ve thought about a lot: every so often during my fifty years in academia, our nutrition faculty would have a retreat and spend some of the time trying to figure out what the word really means. These could not have been very productive, because the same discussion had a way of reappearing at every retreat.
Each time, we’d eventually conclude with some default definition, something resembling the ones found in standard dictionaries. Something like “a process of providing or obtaining food necessary for health and growth”
(Oxford English Dictionary)
or “the act or process of nourishing or being nourished; specifically the sum of the processes by which an animal or plant takes in and utilizes food substances”
(Webster’s).
I don’t like either definition.
Webster’s
definition fails partly on technical grounds because it uses the word
nourished,
which is a derivative of the word
nutrition.
You can’t define a word by referring to itself! That
Webster’s
resorts to this sleight of hand shows how troublesome the word really is.
The other, more substantial problem with the
Webster’s
entry is the word
sum.
I remember sums from grade school math. We added two numbers and got a third. The third, which we called the sum, was nothing more or less than what you got by adding the first two numbers. That’s the very soul of reductionism, remember: the sum (total) can be completely known if you know each individual part.
Both
Oxford
and
Webster’s
use the word
process,
which points to something important but, on its own, is inexcusably vague. The
Oxford
definition focuses entirely on the process of nutrition as something that occurs outside the body: food is either provided or obtained. This leaves no room for nutrition as an internal, biological process, nor a complex one. To reductionists, nutrition is just the arithmetic summation of the effects of individual nutrients. These misleading definitions in two of the most respected and frequently used English dictionaries show how profoundly the reductionist concept is embedded in our culture.
If you were taught statements like, “Calcium grows strong bones,” “Vitamin A is necessary for good eyesight,” and “Vitamin E is a cancer-fighting antioxidant,” you learned nutrition the same way. The same is true if you count calories, or pay attention to percentages on the nutritional labels on packaged foods, or wonder if you get enough protein, or start
slathering your fries in catsup because you hear tomatoes are a good source of lycopene.
These beliefs make sense only in a reductionist paradigm that identifies the component parts of food—the individual nutrients—and figures out exactly what each one does in the body and how much of it we need. And this is precisely what we scientists are trained to do. I was taught nutrition in this way and I taught it the same way to my students. This included an upper-level course in biochemistry at Virginia Tech, an upper-level course in nutritional biochemistry at Cornell, and two new graduate-level courses in biochemical toxicology and molecular toxicology for a new graduate field of toxicology, also at Cornell. Like other faculty in these fields, I followed the typical textbook model of lecturing, mostly focusing on individual nutrients, individual toxic chemicals, individual mechanisms of action (i.e., biochemical explanations), and individual effects, as if there were, for each nutrient or chemical, one main mechanism that explains and perhaps controls the relationship between cause and effect.
When I taught nutrition in this traditional, reductionist way, here’s how it went. We began by considering the chemical structure of the nutrient. Then we discussed how it functions in the body: its absorption across the intestinal wall into the blood; its transport through the body; its storage; its excretion; and the amounts needed for good health. We talked about each nutrient on its own, as if it acted alone in a totally mechanical fashion. In other words, teaching nutrition meant getting students to memorize facts and figures and chemical pathways to pass tests without asking them to think about the context for these discrete bits of information.
We do the same thing in research as we do in education. The gold standard of nutritional research—the type that receives preference for funding and gets published in top-line journals—focuses on one nutrient and one explanation of its effect. My experimental research program focused on the effects of discrete causes, reactions, enzymes, and effects, oftentimes outside of the context of the body as a whole—in part because, as I mentioned, I, too, was taught to think this way,
1
but also because, in order to get research funding, we scientists are forced to focus our hypotheses and experimental objectives on outcomes that can be measured.
Let me give you a specific example from the initial stages of my own research on cancer formation initiated by aflatoxin (AF), a chemical known to cause liver cancer. (As you may recall from the introduction, AF was the carcinogen produced by the peanut fungus I was looking at in the Philippines.)
Figure 5-1
summarizes the process we were studying (using a diet of 20 percent casein, or milk protein).
My lab research at this early stage was completely acceptable according to the reductionist rules. We focused on one kind of carcinogen (AF) that caused one kind of cancer (hepatocellular liver cancer) that depended on one kind of enzyme (mixed-function oxidase) that metabolized AF to produce one kind of highly reactive product (AF epoxide) that produced one biochemical effect (the very tight chemical bonding of the epoxide to DNA that causes genetic damage), each stage of which seemed internally consistent and biologically plausible. And we discovered that the more the carcinogen bound itself to the DNA, the greater the amount of cancer occurred.
2
Aha! This was
the
mechanism that “explained” the effect of protein on cancer!
FIGURE 5-1.
A linear model of cancer causation from aflatoxin
A couple of thoughts about the previous paragraph: first, I don’t expect you to understand everything I wrote. I’m describing complex biological and chemical reactions in the kind of specialized language used by scientists everywhere to communicate with precision. All you need to know is that, according to this model, A causes B, which causes C, which leads to D. So the more A (cancer-causing chemical) you start with, the more D (cancer) you end up with.