In part two of our interview with agricultural economist and scientific researcher Dr. Charles Benbrook, we discuss some good news in the world of organic: two studies from the United Kingdom that deal with the impact of organic production on the nutritional quality of food.
“Organic production,” Dr. Benbrook explains, “substantially increases the average concentration of antioxidants, which are the critical components of fruits and vegetables that bring about their [fruits and vegetables’] impact on health.” As it turns out, the average American isn’t getting enough of these.
Listen above to this conversation and catch part one of Dr. Benbrook’s interview—if you haven’t already—right here.
Interview with Dr. Charles Benbrook – part 2
May 30, 2016
Welcome to Rootstock Radio. Join us as host Theresa Marquez talks to leaders from the Good Food movement about food, farming, and our global future. Rootstock Radio—propagating a healthy planet. Now here’s host Theresa Marquez.
THERESA MARQUEZ: Hello listeners, and welcome to Rootstock Radio. This is Theresa Marquez, talking once again with Dr. Charles Benbrook. We spoke with him last week about the increase of pesticide use in the Midwest that many of us are not aware of but that will impact us, our health, the health of our pollinators, and the environment around us. This week I’d like to talk with Chuck about maybe some of the good news about agriculture. And Chuck, I know that you were involved in two studies that were more or less started or centered in Newcastle University, University of Newcastle in the United Kingdom. Tell us a little bit about those studies.
CHARLES BENBROOK: Well, over the last decade there have been a number of systematic reviews of the literature on published studies on the impact of organic production on the nutritional quality of food. Some of these have focused on fruits and vegetables; others have focused on meat or dairy or eggs. The results of these systematic reviews have been kind of all over the map, and have been driven by the type of statistical techniques used, coupled with the criteria that the scientists used for which studies get counted in a review and how the findings from a particular study are incorporated in the conclusions drawn from a whole body of work. The science and art of these so-called meta-analyses has evolved, along with all other areas of science and statistical analysis.
And a team of scientists came together, of which I was the only scientist from the U.S. to participate, and we carried out really a state-of-the-art meta-analysis using the most sensitive and rigorous statistical tools. Our first paper looked at plant-based foods, so fruits, vegetables, grains, nuts; and the second paper focused on meat, and the third on milk and dairy products. All three papers were published in the British Journal of Nutrition, which is one of the world’s longest-standing and most prestigious nutrition journals. And the team selected it because we knew the topic was a controversial one, and we wanted to ensure that our work would be subjected to a very thorough and rigorous peer review. And let me tell you, it surely was!
TM: So the Journal has its own peer-review team that are not the same people who actually did the meta-analysis.
CB: Correct. The British Journal of Nutrition works like all peer-reviewed scientific journals, where they have a cadre of independent scientists in different areas that they periodically ask to review a paper to see if the findings and conclusion, and conclusions of the paper, are well supported by the data and the analysis and the statistics that were done.
Our team was really pleased to see that in just the last five years, the number of studies to draw upon and incorporate in this sort of meta-analysis have doubled or even more than doubled, so we had a richer database to work with. And there had also been advances in meta-analysis techniques that more effectively dealt with sample size and variability in the quality of studies. And so we took a hard look at what’s out there. There were over 340 papers in the plant area, and we reached a number of very clear conclusions, and that is that organic production substantially increases the average concentration of antioxidants, which are the critical components of fruits and vegetables that bring about their impact on health. And the governments, the reason that they encourage Americans to double their fruit and vegetable intakes is that, in certainly significant part, because we’re getting about, across the population, about half as much antioxidant as we need on a daily basis to maintain optimal health.
TM: Let me just ask you a question. Those studies, those 340 studies of the fruits, vegetables, and plant-based food, were those done all around the globe?
CB: Yes, they were. It’s interesting to look—one of the tables in the supplemental information shows the countries, the number of studies from each country. And it’s interesting, I just calculated this the other day: out of the 347 studies, not quite 100 came from the U.S., and three European countries accounted for 105 . It was Italy, France, and Spain, I believe it was. So, I mean, clearly Europeans have invested more heavily in probing the differences between organic production systems and conventional systems in terms of food nutritional quality. European countries and the European public are much more concerned about food quality, the connections between food quality, dietary choices, and human health, than the typical American. And this is reflected in where they invest their research dollars. So it has been regarded as perfectly legitimate and important science over the last twenty years across Europe to explore the impact of alternative agriculture production systems and technology on the nutritional quality of food. And indeed, a significant number of studies show that we have profoundly altered the nutrient composition in food.
TM: Through conventional and biotech ag?
CB: Yeah, but actually, Theresa, the biggest factor that has shifted critical components of the diet is the dependence on corn and soybean supplements across all of livestock agriculture and aquaculture. When you think about it, all of the major livestock species that deliver about half the calories of the typical American diet, and all fish, their diets are firmly grounded in plants—grasses and legumes. And shifting all of those species to a diet that is composed predominantly of corn and soybeans—as is the case with pigs and chickens and beef cattle and dairy cattle and many farm-raised fish in the United States, in Europe, and around the world—shifting to corn and soybeans as sort of the foundation of the diet has dramatically increased intakes of omega-6 fatty acids and dramatically reduced intakes of omega-3s.
And it turns out that the ratio of the balance between omega-6 and omega-3 intake has enormous consequences on human metabolism, on overweight and obesity, on diabetes, and on the suite of health problems that are so common in America called the metabolic syndrome. I think that the most significant finding from these comparative studies really is that the way that agriculture has evolved over the last fifty years, we’ve really shifted around the types of fat in the diet. And it turns out now that a majority of scientists finally are admitting that the biggest change in the American diet is not how much fat we eat but it’s the type of fats that are typically consumed through animal products and through fried foods.
TM: For those of you who just joined us, we’re talking to Dr. Charles Benbrook, who is not just an ag economist but also an expert on pesticide usage in the United States and in the world.
Well, you know, it’s exciting to me to see these Newcastle studies. Certainly the fruits and plant-based one where they looked at the 340, approximately, or a little bit more even, studies on the benefits of organic to fruits and plant-based food. Besides the fact that it had higher antioxidants, wasn’t there some evidence about less heavy metals, especially cadmium?
CB: Yes. There are a number of other different nutrients, depending upon whether we’re talking about grains or nuts or tomatoes or apples, that are higher in organic. And in some cases there are negative things that we don’t want in the diet that are substantially lower in organic.
Now, it is true that there are a couple of nutrients that tend to be higher in conventional food, and the most significant one being protein. Nitrogen is sort of a building block of protein, so in conventional production systems, where farmers make sure that their plants are never deficient in nitrogen, it makes sense that protein levels are going to be elevated and at the upper end. And we do know that one of the greatest challenges that organic farmers face is keeping enough nitrogen in the system, because they can’t use the potent and low-cost forms of nitrogen that are relied upon by conventional farmers.
But it’s important to note that the average American gets about twice as much protein as they need on a daily basis. So protein is not a limiting nutrient in the U.S. diet in terms of public health outcomes, whereas antioxidants, vitamin C and vitamin E and the other plant phytochemicals that contribute to total antioxidant activity—those nutrients clearly are not supplied adequately in the typical American diet. And that’s why people think that we’ll get sort of the biggest public health bang for the buck by increasing antioxidant-rich foods like blueberries and raspberries and spinach and kale—and, whenever possible, growing those fruits and vegetables organically, where you get a 20 to 30 percent increase in the antioxidant levels in them.
TM: Tell us now more about the fat, the good fat, the increase of omega-3 that the meat and milk studies showed.
CB: Okay. Well, all of the studies comparing production systems in terms of fat show relatively modest differences in total fat, modest differences in the amount of saturated fat, and also little difference in monounsaturated fats. The big differences are in the polyunsaturated fatty acids. And this is the categories of fats that include the omega-6 fatty acids and the omega-3 fatty acids. And it turns out that corn and soybeans are very high in linoleic acid, which is the predominant omega-6 in the diet and in plant-based food. And corn and soybeans also happen to be quite low in the omega-3 fatty acids that play such an important role in human metabolism, in controlling hunger, in the development of the neurological system, in aging, et cetera.
So when, starting in the 1950s, because of shortages of butter fat, the postwar period, the government felt that in order to reduce saturated fat intake—and some studies suggested some health benefit in that—the government aggressively pushed a switch from full-fat butter to margarine. Well, margarine is composed of trans fats, and now we know that trans fats are the worst class of fats in the diet. So the science community and government has mismanaged fat intake in some profound ways for a half century now. And we still haven’t caught up in our nutritional guidelines for the nation with what science is saying. And for example, the WIC program still encourages mothers to serve their children skim or 1 percent milk.
TM: Also, it’s legislated that’s the only milk that can be in public schools.
CB: Correct. But the science now shows that it’s much healthier for children to consume whole-fat dairy products, for a variety of reasons, and one of the reasons is that in whole-fat dairy products they’re getting more of these omega-6 and omega-3 fatty acids.
But if the milk or the cheese or the yogurt is from a conventional dairy farm, milk from a conventional dairy farm where the cows are fed a lot of corn and soybeans and very little or no fresh grass and pasture, there’s about six units of omega-6 in conventional milk for every one unit of omega-3. If you look at the average organic dairy farm, where cattle have to spend a significant amount of their time during the growing season on pasture and have at least 30 percent of their dry-matter intake, or basically their total diet, coming from pasture, you see a drop in the key ratio of omega-6 to omega-3 fatty acids from about 6:1 to 2:1. And 2:1 is a much healthier ratio or balance in these critical polyunsaturated fatty acids than conventional milk or other types of conventional meat.
TM: So the Newcastle study was…and how many studies did they do on the meat and on the milk, on those mega studies?
CB: There were over a hundred studies on milk and dairy products, and I believe about ninety or just under ninety on meat. the database on meat is a bit thinner than on the dairy and milk, but it’s getting stronger. And some of the studies, including a very high-quality study done at the University of Minnesota by a professor named Brad Heins was published in the widely respected Journal of Dairy Science two years ago. What Brad and his team did is they took a set of steer cattle from their organic dairy farm and they broke them up into three groups. One group went into a feedlot and was fed a traditional feedlot ration, which was composed primarily of corn and soybeans with a little bit of alfalfa hay. Those crops came from conventional sources. A second group of the steers was fed essentially the same feedlot diet but only from organic sources, so it was an organic conventional feedlot diet. And the third set of steers was fed a grass-based diet and finished solely on grass.
And basically, the steers that were fed predominantly corn and soybeans during the finishing stage had ten units of omega-6 for every unit of omega-3, which is a highly skewed and unhealthy ratio of these fatty acids. And the grass-fed steers had about one to one, just a huge shift, a much bigger shift than we typically see, for example, in total antioxidant activity in an apple or a pear or spinach, where a 20 to 30 percent difference is actually pretty significant. But in the case of the composition of fat, shifting animals from a grass-based diet to a corn- and soybean-based diet has a much bigger and dramatic impact on the balance of fatty acids. And this shift, in turn, I believe, is really at the heart of some of the biggest public health problems we face in America and Europe and indeed around the world: overweight and obesity, diabetes, and this metabolic syndrome.
TM: Well, this kind of is an exciting idea that what seems like the natural habits of animals—and that is to eat grass; I mean, cows have four stomachs and they like grass—in that letting them do what’s natural for them, it almost feels like common sense that they would produce a healthier product, versus trying to get them to produce more or get fatter faster by pumping them with corn and soy, which isn’t very good for our environment, that we know. How should we, as the public, do you think, take a look at that? And should we be out there promoting more grass-based agriculture? I guess that would be one question.
CB: Well, absolutely. You know, incrementally shifting livestock agriculture back to a grass-based system—I mean, not eliminating completely corn and soybeans on conventional farms, but substantially changing the mix—would be good for the animals, good for the land and the environment. And the new piece of the puzzle that really has come on-stream in just the last two or three years is it’ll be dramatically better for human health. And again, it’s difficult for the government to admit and acknowledge that thirty or forty years of dietary advice has been misguided and has actually supported a less healthy diet than what we used to enjoy. So it’s a slow change.
If you look at the recently issued dietary guidelines, they have finally stopped recommending reductions in cholesterol intake, as the science supporting the notion that cholesterol is a bad thing just really collapsed. But unfortunately, the revision in the dietary guidelines does not go as far as it should, particularly on the topic of encouraging reductions in omega-6 fatty acid intakes and increases in omega-3 intakes through consumption of grass-fed and grass-based animal products.
TM: Well, I’m so happy that the Newcastle study and other studies, this study from Minnesota that you’re referring to, all kind of confirm what I think we in organic have known for a long time, and that is there’s something very commonsense about letting animals do what is natural for them to do, and that is eat grass and pasture.
CB: Well, Theresa, you know, I think the big thing holding back the kind of transition that needs to happen is really about infrastructure investment, and the fact that there are whole industries and millions of people that derive their current income from the type of agricultural inputs and machines and food chains that we as a nation have consciously supported and invested in over the last fifty years. And in order for a more grass-based livestock industry to function as efficiently and effectively as feedlot agriculture does today will require twenty or thirty years of patient and systematic investment in, for example, veterinarians that understand about ruminant nutrition with rations based on forages, as opposed to corn and soybeans; and new equipment to handle and store grass-based and legume-based feeds; new genetics, changes in the genetics of animals. There are so many things that have to change in concert to advance the cost effectiveness and efficiency of a more grass-based livestock agriculture that just, it isn’t happening now on the scale that’s needed because public policy has sort of locked the agricultural system into the way we’ve been producing food and producing meat and dairy products over the last thirty or forty years.
TM: Well, that certainly is…the building of the infrastructure, what a challenge. And certainly we’re seeing that this change is a lot more complicated, as you’ve presented it, Chuck, and I really appreciate that insight. I do believe, however, that we are seeing some models out there that are taking this grass-based agriculture and figuring out how to scale it up. And I think we’ll see more of it, and I surely hope it doesn’t take twenty years.
I think that we should probably not close this show today without the big million-dollar question out there that we keep getting hammered on by conventional and biotech ag. And that is: If we change this agriculture, we won’t be able to feed the world. I’d love to hear a comment from you on that one.
CB: Well, just to point out the obvious: Conventional agriculture dominates around the world, and we still have, according to the FAO, 850 million people a day that don’t get enough to eat and are suffering from food insecurity. It’s very clear to people that understand this problem and that work on it at a local level, food insecurity is an economic problem, an access problem, it’s a social justice issue, it’s clearly linked to poverty and social disruption. Food insecurity is most acute in parts of the world that are plagued by civil strife and war. And people all around the world that have money have no trouble buying enough food to meet basic caloric and nutritional needs.
So food insecurity issues aren’t about production. The world already produces 50 percent more calories overall, if the food that was produced were evenly distributed. So producing more food in the same ways is not going to make a substantial dent in current levels of… It’s the wrong solution to the underlying problems that lead to hunger.
TM: Listeners, we have been listening to Dr. Charles Benbrook, ag economist and expert in the production of food using pesticides and its impact on our health and the environment. And Chuck, I so appreciate your great insights in speaking with me today, and I look forward to the next time we get together and can talk about some of these issues.
CB: My pleasure, Theresa. Thank you very much.
TM: Thank you.
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