Pressing for quality
Protein, fat, carbohydrate and alcohol provide virtually all of the calories that we consume. Fat, carbohydrate and protein, as macronutrients, make up almost all the weight of food, aside from water, with the remaining small amount being the vitamin and mineral micronutrients. The amounts of these latter micronutrients needed for optimum health are tiny (milligrams to micrograms).
The protein gap
The most important issue in nutrition and agriculture during my early career was figuring out ways to increase the consumption of protein, making sure it was of the highest possible quality: My colleagues and I all believed in this common goal. From my early years on the farm to my graduate education, I accepted this virtual reverence for protein. As a youngster, I remember that the most expensive part of farm animal feed was the protein supplements that we fed to our cows and pigs. Then, at graduate school, I spent three years (1958-1961) doing my Ph.D. research trying to improve the supply of high-quality protein by growing cows and sheep more efficiently so we could eat more of them
Feeding the children
SO this was the climate at that time, and I was a part of it as much as anyone else. I left MIT to take a faculty position at Virginia Tech in 1965. Professor Charlie Engel, who was then the head of the Department of Biochemistry and Nutrition at Virginia Tech, had considerable interest in developing an international nutrition program for malnourished children. He was interested in implementing a “mother craft” self-help project in the Philippines. This project was called “mother craft” because it focused on educating mothers of malnourished children
A revelation to die for
It our project. As I mentioned before, we first had to resolve the problem of AF contamination in peanuts, our preferred protein food. The first step of investigating AF was to gather some basic information. Who in the Philippines was consuming AF, and who was subject to liver cancer? To answer these questions, I applied for and received a National Institutes of Health (NIH) research grant. We also adopted a second strategy by asking another question: how does AF actually affect liver cancer? We wanted to study this question at the molecular level using laboratory rats. I succeeded in getting a second NIH grant for this in-depth biochemical research
The nature of science-what you need to know to follow the research
Proof in science is elusive. Even more, than in the “core” sciences of biology, chemistry, and physics, establishing absolute proof in medicine and health is nearly impossible. The primary objective of research investigation is to determine only what is likely to be true. This is because research into health is inherently statistical. When you throw a ball in the air, will it come down? Yes, every time. That’s physics. If you smoke four packs a day, will you get lung cancer? The answer is maybe. We know that your odds of getting lung cancer are much higher than if you didn’t smoke, and we can tell you what those odds (statistics) are, but we can’t know with certainty whether you as an individual will get lung cancer.
Correlation versus causation
In many studies, you will find that the words correlation and association are used to describe a relationship between two factors, perhaps even indicating a cause-and-effect relationship. This idea is featured prominently in the China Study: We observed whether there were patterns of associations for different dietary, lifestyle and disease characteristics within the survey of 65 counties, 130 villages and 6,500 adults and their families. If protein consumption, for example, is higher among populations that have a high incidence of liver cancer, we can say that protein is positively correlated or associated with liver cancer incidence; as one goes up, the other goes up.
Mechanisms of action
Oftentimes correlations are considered more reliable if other research shows that two correlated factors are biologically related. For example, telephone poles and heart disease are positively correlated, but there is no research that shows how telephone poles are biologically related to heart disease. However, there is research that shows the processes by which protein intake and liver cancer might be biologically and causally related.
After obtaining the results from a variety of studies, we can then begin to use these tools and concepts to assess the weight of the evidence. Through this effort, we can begin to understand what is most likely to be true, and we can behave accordingly. Alternative hypotheses no longer seem plausible, and we can be very confident in the result. Absolute proof, in the technical sense, is unattainable and unimportant. But common sense proof is attainable and critical.