No more peaches, no more blackberries! As my colleague, Jeff O’Hara, and I pore over the list of fruits and vegetables coming in our shared community supported agriculture (CSA) delivery, we are facing the sad fact of seasonal eating. Seasons end. Yes, we will still get tomatoes and butternut squash—but oh what a summer this has been for berries and peaches.
The Tuesday afternoon arrival of bags of organic fruits and vegetables has turned out to be a highlight of the summer for Jeff and me. Although not certified, our farmer employs the same practices that make organic produce a healthy choice and delivers them fresh from field right to our downtown DC office.
Of course, like most enthusiastic consumers of organic food, Jeff and I have reasons besides taste and freshness for choosing it. For a start, we both value the best-known features of organic agriculture: it prohibits antibiotics and synthetic pesticides.
News reports on a study from Stanford
So what do I make of a recent, widely reported story on National Public Radio saying that a new study by Stanford University scientists means that there is “hardly any evidence at all that organic food is healthier” and implies that Jeff and I might have been duped?
As a scientist, I am pleased to see a major meta-analysis (a study of studies) on the nutritional and safety aspects of organic food, but I found the interpretation by the authors of the study and news media disconcerting—and surprising.
The Stanford analysis confirmed that in comparison with conventional food, organic food has significantly lower pesticide levels, lower multidrug-resistant bacteria levels, and higher beneficial fat levels. In my book, that’s a pretty good case that organic food is healthier.
The study failed to find higher level of vitamins and other nutrients in organic food, however, and somehow in the minds of reporters and opinion columnists the evidence on vitamins trumped the evidence on antibiotics and pesticides. From a scientific standpoint, that doesn’t make sense. Nutrition isn’t the only health benefit that matters.
I also found the media coverage misleading in that it seemed to treat this study as as a final answer to the questions about organic agriculture rather than what it is: a first approach to those answers.
The Stanford paper demonstrates the challenge of comparing organic and conventional food production systems. It looks at hundreds of studies on different kinds of foods grown in different ways here and in Europe. The studies involve a bewildering number of factors: What constitutes “organic?” Were the vegetables similarly ripe? Was the milk pasteurized or raw? Was the milk produced in the summer or the winter?
The issue’s complexity means that scientists will have to conduct many more studies, over much longer time periods, and under many different kinds of conditions, to reach broad conclusions about the impacts and value of organic agriculture.
The 237 studies that met the criteria for the Stanford paper are just the beginning of what’s needed to settle the question of the broad impacts of organic agriculture. The fact that the paper identified only five studies that evaluated people who consumed a predominately organic diet, rather than single foods, and found no studies that examined pesticide levels in adults shows how far science has to go.
What should consumers think?
Should Americans who eat organic food feel duped based on this study? Absolutely not.
The simple fact that organic food is produced without antibiotics and pesticides is enough to justify their buying it.
As my share-partner, Jeff, an economist, put it, “’No pesticides and no antibiotics’ is good enough for me. I’ll let the science catch up on other health benefits.” He calls it the precautionary principle on a plate.
This is a great reason to prefer organic but as discussed below there are other reasons, also supported by science. And, of course, scientists will continue to study these systems. UCS welcomes this research but cautions that consumers don’t need to wait for the results of more studies to feel good about their decisions to support and purchase organic.
Shortcomings of the Stanford study
The Stanford study’s interpretation of its findings has some major shortcomings.
The study confirmed that organic foods have low levels of pesticides but disparaged the finding because the pesticide levels in conventional food meet federal Environmental Protection Agency (EPA) standards. The suggestion that EPA standards represent acceptable levels of pesticides in food is troublesome. EPA standards are at best moving targets that tend to lag behind the advancing edge of new science (for example, the ramifications of pesticides as endocrine disruptors.) Some recent science compiled discussed by Dr. Charles Benbrook not cited by the Stanford study presents strong evidence that pesticides at dietary levels can adversely affect children. We need much more information to fully understand the role of pesticides in our food and environment. In the meantime, minimizing pesticides in food is the cautious and responsible course to take.
The Stanford study also confirmed that organic products have lower levels of multidrug-resistant bacteria than conventional ones. That supports the conclusion that, in addition to reducing one’s personal risk of acquiring drug-resistant infections, organic production helps address the public health threat posed by the erosion of our medical arsenal as a result of antibiotic resistance.
Regardless, the Stanford study dismissed the public health contribution of organic by minimizing the contribution of animal use of antibiotics to the resistance crisis. Contrary to the paper—which relied on an out-of-date 2001 report from the U.S. Department of Agriculture—the existing science on this issue is conclusive: Massive use of antibiotics in animal agriculture is a significant contributor to the loss of efficacy of human use drugs. Food animal systems that can completely avoid antibiotic use are a major boon to public health.
Other benefits of organic agriculture
Stories on the Stanford study tended to skip over benefits not covered in the paper, although those benefits account for much of the enthusiasm for organic food.
Organic practices provide habitat for such beneficial organisms as pollinators and provide food animals substantially better lives. Organic producers have no need for antibiotics because animals fed the right food (grass in the case of cows), and provided low-stress living conditions, rarely get sick.
Organic systems can also reduce emissions of active nitrogen and reduce coastal ecosystem degradation. Because they rely on a diversity of crops, organic farms are resilient to environmental stress. The high levels of soil organic matter encouraged by organic practices enables soil to hold water and resist drought.
UCS is interested in all these issues and urges more science to expand our understanding of agriculture, health and the environment.
But there is no need to wait for these studies. Jeff and I—and consumers across the county—already have plenty of reasons to prefer organic food.
Now Jeff and I are going to divvy up our bag of beautiful CSA vegetables.
Support from UCS members make work like this possible. Will you join us? Help UCS advance independent science for a healthy environment and a safer world.