Scientific proof

There were two big stories in the science sections of newspapers and on-line news sites recently. One was directly related to organic agriculture, and the other was related indirectly.

The first story was the coverage of a study published in the “Annals of Internal Medicine” by a group of scientists from Stanford University. The lead researcher, who also is a physician, was looking for an answer for her patients who frequently asked her if organic food was better for them. She and her colleagues undertook to review the research done on the subject over the last decade or more. They sought to determine if there was any scientific basis to the belief that organic foods are more nutritious and safer. Headlines announced in attention grabbing headlines: “Study proves: Organic food not more nutritious!” Defensive conventional, industrial food proponents carefully selected among the study’s findings and crowed that organic food is an expensive marketing hoax.

I found the excitement proclaimed over this study which studied other studies unwarranted. While the Stanford researchers pointed out that the study of studies was not funded by any outside source, the findings of this group could not be any more accurate or helpful than the original research. The studies reviewed often were funded by industry dollars and Stanford University itself receives more than a tiny bit of revenue from food industry sources.

This review looked at thousands of pieces of research, but did not analyze many of the available studies because they were not, in the opinion of the Stanford scientists, scientifically well designed. They also only reviewed research available in English. Out the thousands of papers considered, they reviewed 237. Those included 17 studies (six of which were randomized clinical trials) of populations consuming organic and conventional diets, and 223 studies that compared either the nutrient levels or the bacterial, fungal or pesticide contamination of various products (fruits, vegetables, grains, meats, milk, poultry, and eggs) grown organically and conventionally. The duration of the studies involving human subjects ranged from two days to two years. It is noteworthy that there were no long-term studies of health outcomes of people consuming organic versus conventionally produced food.

The study found levels of some nutrients to be higher in organic foods and others to be higher in conventionally produced foods. These studies were discounted as “inconclusive.”

Since long-term studies of health outcomes would require controlling for many other factors and behavioral changes, none have been done. They would be very expensive and difficult to design. Human health is a very complex issue and human behavior is unpredictable and hard to control.

Analyzing and comparing the nutrient content of organic as compared to conventional foods is a futile and useless exercise. The research studied by this group of scientists is based on reductionist thinking. If one were to analyze an organic strawberry’s vitamin C content and compare it to a conventional strawberry and to a vitamin C tablet, the tablet would have the highest nutrient concentration. That wouldn’t make it the healthiest choice.

The researchers did concede that organic foods are less likely to be contaminated with pesticides. Not only was the incidence of contamination less frequent, but organic produce had fewer kinds of pesticides per sample and the residues found were usually traces of far less toxic pesticides than the residues on conventional samples. In one study four of 81 (< 5%) organic samples had detectible residue of one pesticide on them. In the same study 1354 of 4069 samples had detectible pesticide residues (> 33%). Most conventional fruit and vegetable samples contained two to five different chemical residues and in several important crops, about 10% of samples contained eight or more residues. This highly quoted research, however, uses convoluted and confusing ways of describing these findings which downplays the differences found. They maintain that their findings are not a significant health issue because the residues found were below the limits of exposure allowed by the Food and Drug Administration. Their conclusions do not consider the growing body of research that connects exposure to pesticides by pregnant women, babies and old people with some of the many ills that plague us. Nor did they (nor does the FDA) consider the cumulative effects of pesticide exposure of the effects of the chemical soup being consumed on those fruits and vegetables that have multiple residues present in addition to those in the air and water.

While the authors seemed to be looking for proof that organic food is not worth a premium price, they did also, surprisingly, conclude that organic meats and poultry were less likely to contain antibiotic resistant strains of bacteria. They didn’t seem to think this was a significant safety difference, but neither did they describe what a “significant” difference in nutrition or safety would be.

The second bit of science news that piqued my interest was a report about the latest discoveries concerning human genetics. A decade ago geneticists were excited to have mapped the genes in human DNA. They found the connection between about 1 percent of the genetic material in the human genome and the proteins they control. The scientists at the time were baffled about the function of the remaining 99% of genetic material. They were fairly sure that it had no function and even called it “junk.” The latest research shows that this “junk” indeed has very important functions. The genetic material they thought was unused turns out to function as tiny switches which turn various genes on and off within cells. Now geneticists think mutations in these tiny switches may have more to do with cells becoming cancerous or diseased than mutations in the genes themselves.

It turns out that genetics is not the simple, dominant, recessive, one gene, one protein, system that I learned about in genetics class forty years ago. Nor is it the simple tinker toy, interchangeable component system that proponents of genetic modification would have us believe. So much for the simple explanation of gmo’s in which genes are simply, cleanly and efficiently inserted into the double helix, producing a predictable, consistent result free of unintended mutations. What happens to the rest of the chromosome when this is done? Does this manipulation affect the neighboring “junk?” How much more do we not understand?

Our science is limited by the questions we ask and by our own arrogant thinking. We too often think we have the answer and look for science to prove it. Sometimes along the way we find out that life is complex, interconnected and multi-layered. Humans in every age have believed they have found the secrets of life. Every new age proves we were wrong.

The world’s most respected scientists once believed that the earth was flat.

Copyright © 2012 Janet Jacobson and Sustaining the Northern Plains