by Jon Barron
11/15/2010 Posted
Another day, another stupid study! In case you missed the headlines:
In fact, not one of these headlines accurately represents the study results. The study categorically did not claim that antioxidant levels were the same in organic and conventionally grown food. What it did claim is that polyphenol levels were the same. Polyphenols are only one particular subset of antioxidants. That's very different from claiming that the levels of all antioxidants were no different. It would be like if Roger Ebert, the film critic, said that Robin Williams, the comedian, was a good actor, and then all of the newspapers ran headlines that said, "Roger Ebert says all comedians make great actors." You can't extrapolate from the specific to the general. But the problems connected with this study go far beyond media exaggeration. In fact, there are three problems with the study results as promoted.
The bottom line is that with a little simple analysis, we can easily dismiss the study, which we will do in a moment. But, more importantly, the study opens up several much bigger issues about organic foods that, although outside the purview of the study, are ultimately more important than the study itself. And that's the true focus of this newsletter.
As you will notice from the headlines above, every one of them says the study is about antioxidants in general. It is not. The study was published in the Journal of Agricultural and Food Chemistry (2010, 58 (19), pp 10323--10329) under the title Effects of Organic and Conventional Growth Systems on the Content of Flavonoids in Onions and Phenolic Acids in Carrots and Potatoes. Notice the word antioxidant does not appear in the title of the study. In fact, the word antioxidant does not appear in the entire published results of the study, not one single time. The study categorically makes no claims in regard to antioxidants in general, only about a particular subset of antioxidants, polyphenols -- and specifically, two divisions of polyphenols known as flavonoids and phenolic acids. Is this distinction important? Critically!!
To quote from the study: "The objective of our study was to compare the content of selected flavonoids and phenolic acids in organically and conventionally grown onions, potatoes, and carrots and to evaluate if the ability of the crops to synthesize selected secondary metabolites is systematically affected by growth systems across different growth years as well as geographic locations (soil types)."
Or to translate into English: "The objective of our study is to determine if there is any difference in the amount of quercetin or caffeic acid in organic potatoes, onions, and carrots versus conventionally grown crops."
So why is this important? Polyphenols are comprised of carbon, oxygen, and hydrogen. As it turns out, these are readily provided by water and carbon dioxide in the air. Fertilizer, either organic or synthetic, is only incidental to their production. Consider that the chemical formula for quercetin (the onion flavonoid the study focused on), is C15H10O7. The chemical formula for caffeic acid, the primary phenolic acid they tested for in potatoes and carrots, is C9H8O4. As you can see, they are both comprised entirely from carbon, hydrogen, and oxygen -- components that come from water and carbon dioxide in the air. When it comes to producing phenols, there is no inherent advantage in using manure VS conventional fertilizer since fertilizer is incidental to the formation of phenols. In other words, choosing to measure phenols as the basis of a fertilizer comparison totally negates any potential advantages for organic fertilizer. In a sense, the study was a rigged card game, the results, for the most part, predetermined.
But the bizarreness doesn't end there. Let's talk for a moment about the foods they chose to study for their polyphenol levels -- and how that relates to where their actual nutritional value really lies.
What a strange selection of foods to use for an antioxidant comparison. Who in the world would consider using potatoes in a study about food antioxidants? Carrots maybe, but potatoes?! Were the researchers deliberately designing the study to fail, or were they just plain ignorant about nutrients in food? Raspberries, acai, and baking chocolate, absolutely! All leap to mind as high antioxidant foods. But potatoes? Surprise, for what it's worth, potatoes actually have a higher ORAC value than onions and carrots. In fact, potatoes have an ORAC value of 1,138, onions 913, and carrots 436. To give you a point of reference, though, tortilla chips have an ORAC rating of 1486 -- higher than any of the foods tested. Now, to be fair, I've talked before about the iffy nature of using ORAC values to determine antioxidant potency. Or to put it another way, does anyone really believe that tortilla chips have three times the antioxidant value of carrots? But the real question is: in a study comparing antioxidant levels based on different growing methods, why wouldn't you choose to evaluate foods known for their antioxidant value, like rosehips at 96,150 ORAC -- or raisins (golden, at 10,450) or rice bran (at 24,287) or walnuts (at 13,541)? Ultimately, they probably chose to study potatoes, onions, and carrots because they are among the most commonly eaten vegetables, but that doesn't make their selection right for a study of antioxidants. And at least choose to analyze the key antioxidants in each vegetable. We're talking about carotenoids in carrots and the sulfur-bearing compounds (GPCS, allyl propyl disulphide, AMT, AMD, DAT, DAS, and Sodium thiosulfate) in onions. It is the sulfur compounds in onions that may help reduce the risk of heart disease and cancer and help destroy invading pathogens. That's where the primary health benefit of onions can be found. And when it comes to potatoes, you're talking bangers and mash, not antioxidants.
But then things get even more bizarre. When thinking of the nutritive value of onions, how many naturopaths would turn to onions as a quercetin source? Surprisingly, on an ounce-for-ounce basis, onions rank in the top ten of commonly eaten vegetables when it comes to quercetin. The content of quercetin in onions is estimated to be 13.27 mg per medium-sized onion (about 100 grams). With buckwheat, on the other hand, you're looking at 23.09 mg per 100 g serving. That's twice the concentration of quercetin, and it's a whole lot easier to eat 3 ounces of buckwheat as opposed to a whole onion. Incidentally, elderberries come in at 42 mg per 100 g serving.
And as for carrots, why in the world would you assess their antioxidant value by measuring quercetin or phenolic acid levels? Carrots are the epitome of an entirely different group of antioxidants known eponymously as carotenoids. When testing carrots for antioxidants, wouldn't you want to test for carotenoids?
When all is said and done, though, there would likely be little difference between conventionally grown and organic produce when testing for any of the antioxidants we've mentioned so far, since the phenols and carotenoids are all based on oxygen, hydrogen, and carbon. But what about other antioxidants that contain elements not found in air and water and that are also important markers of food value? How do they stack up based on fertilizer choices?
One of the problems with commercial fertilizers is that in order to be cost effective, they provide plants with the minimal ingredients needed to make the plant grow. When it comes to conventional fertilizers, you're pretty much talking about NPK --nitrogen, potassium, and phosphorus. Organic fertilizers, on the other hand, tend to supply nutrients across the entire spectrum (with a huge qualifier that we'll discuss in a moment). Why does this matter?
Consider selenium, one of the most powerful antioxidants known. If selenium is in the soil, plants pick it up. If it's not in the soil, they don't pick it up. They don't actually need it to grow. It helps with their defence against pests, but for the most part, plants will "look" just fine if grown in selenium defienct soil. Plants require only 16 nutrients to grow; selenium isn't one of them. In other words, if selenium isn't in the soil, the final crop will be selenium deficient. It will no longer be found in the plant, either alone or as part of any other molecules. When farms rely exclusively on NPK conventional fertilizers (nitrogen, phosphorus, and potassium based fertilizers) for raising their crops, all of the minerals such as selenium are soon depleted from the soil and drop out of the equation, as do any antioxidants that require their presence. Overall, the plant's phenol level will be minimally changed (since selenium is not needed for production of phenols), but its total antioxidant value will be profoundly lessened because the powerful antioxidant, selenium, will be missing. (As we'll discuss in a bit, the use of pesticides may produce a different result in regard to polyphenols.) To summarize: conventional and organic fertilizers will produce similar levels of polyphenols, but not selenium based antioxidants. Likewise, sulfur based antioxidants will be substantially higher in organic crops, as will levels of antioxidants that require metals such as copper, zinc, iron, magnesium, germanium, or nickel -- for all the same reasons.
Now, I did mention a couple of paragraphs ago that there's a huge qualifier to this analysis.
Not all organic fertilizer is equal. A key question is, "Where did the manure come from?" Did it come from organically raised animals or conventionally raised animals? This is important for two reasons.
What this means is that some so-called "organic" manure fertilizers might provide no material benefit over conventional synthetic fertilizers. But the researchers thought of that…almost. They ran "two" organic crops, which they called "A" and "B." The "A" crop relied on animal manure for nutrients. For the crop grown in the "B" field, however, the nutrient supply came from the use of cover crops, mainly legumes. Cover crops are planted between periods of regular crop production to prevent soil erosion. They are then plowed under to provide humus and nitrogen for the soil. (Note: animal manure was also applied to the onion fields to satisfy the high nitrogen demand of that particular crop.) The cover crops were generally grown in the autumn after the main crops and plowed back into the soil in the spring before the main crops were grown. Nice try, but you still have the same problem. If the minerals aren't in the soil in the first place, they're not going to magically appear in the cover crops. Thus, plowing them back under doesn't add a single mineral to the equation -- only nitrogen, phosphorus, potassium, carbon, oxygen, and hydrogen. Unless you deliberately remineralize the soil, minerals will not magically appear in the plants.
So what minerals and antioxidants are we talking about that might be missing?
Glutathione peroxidase, superoxide dismutase (SOD), and catalase are the three primary enzymes produced in the body as an antioxidant defense. As we've already discussed, selenium is a key component of glutathione peroxidase. Iron, on the other hand, is required for catalase. Catalase is a specific for protection against tumors. A little catalase can go a long way: one catalase enzyme molecule can catalyze the breakdown of five million molecules of peroxide radicals into water and oxygen in just one minute. As for SOD, copper, zinc, iron, magnesium, and nickel are all required for the construction of the various SOD molecules.
You get the idea. There are a number of essential antioxidants that require more than carbon, oxygen, and hydrogen for their construction. Basing a study on the antioxidant value of foods measured only by the amount of phenols present provides an extremely misleading picture. The bottom line is just because there is little measurable difference in phenol levels between organic and conventional produce doesn't mean they have even close to the same antioxidant values, let alone nutrient values.
In the end, the study concludes: "On the basis of the present study carried out under well-controlled conditions, it cannot be concluded that organically grown onions, carrots, and potatoes generally have higher contents of health-promoting secondary metabolites in comparison with the conventionally cultivated ones. The ability of crops to synthesize selected secondary metabolites was not systematically affected by the growth system across different growth years and geographical locations."
Well, that sounds pretty conclusive, but what about other studies? Do they confirm that conclusion, or not?
The bottom line is that there is a great deal of evidence that organic and sustainably grown produce produces greater levels of antioxidants than conventionally grown produce. That, combined with some of the "unusual" choices made in the current study, renders its conclusions highly suspect.
Which brings me back to the media universally getting their headlines wrong and totally missing the mark concerning the study's conclusions -- let alone not challenging the holes in the study's logic.
There's little point in once again beating up the mainstream media for getting, in the parlance of the day, "IT" wrong when it comes to alternative health. In fact, thanks to shrinking budgets, the days of investigative journalism when it comes to basic health issues is long gone. The media is now a mere transcription service for so-called peer-reviewed journals. If the media finds a story published by such a journal "headline worthy," it uncritically looks for a way to dumb down the journal's press release into headline friendly Pablum. No attempt is made to question the study. Only rarely does the media extend so far as to make a phone call to elicit a contrarian point of view in their article -- but no real investigation is ever done. Beating up on the media, though, for lack of follow through is a bit like beating a homeless dog for being homeless. The dog is not homeless by choice, and likewise, the media does not transcribe study press releases by choice, but rather because they no longer have the resources to do anything else.
But of course, that's still no excuse for wrongly sensationalizing headlines.
The idea of "organic food" has its roots some 60 years ago when Oxford University agriculturalist, Lord Northbourne, in his book Look to the Land designated the natural alternative to chemical farming as organic farming. The term stuck and over time became the defining term for "natural" agriculture. Until the early 90's, the use of the term was a bit loosey-goosey, but since organic farming was only practiced by those really into it, anything labeled organic tended to be truly organic. However, in the early 90's, under the auspices of the Organic Foods Production Act of 1990, the USDA took control over all organic farming in the United States -- and more importantly, control over the definition of the word organic.
The definition of "organic" in the act opens the door to all kinds of interpretation and abuse:
To be sold or labeled as an organically produced agricultural product under this title, an agricultural product shall
- have been produced and handled without the use of synthetic chemicals, except as otherwise provided in this chapter;
- except as otherwise provided in this chapter and excluding livestock, not be produced on land to which any prohibited substances, including synthetic chemicals, have been applied during the 3 years immediately preceding the harvest of the agricultural products; and
- be produced and handled in compliance with an organic plan agreed to by the producer and handler of such product and the certifying agent.
Unfortunately, this definition allows for many exceptions. Some exceptions come from the blatant ignoring of the law by those supposed to enforce it, and some exceptions are gently nudged in later. For example:
In the end, one study that distortedly analyzes potatoes, onions, and carrots doesn't really matter. Most people are going to ignore the newspaper headlines, or never even see them for that matter, and the sale of organic products will continue to grow at about 20% a year, as they have for the last two decades. Even the media falsely touting the study as the death knell of organic produce will have little impact. Why? Because organic food is big business now. Companies are adding so-called, high-antioxidant, organic foods to everything under the sun and sticking the words on their labels.
The bottom line is that there is too much money invested in organic foods now for them to go away, no matter what studies come out. This, of course, leads to the danger of co-option, where large corporations take over and totally neuter the meaning of "organic" to suit their marketing purposes. The bigger danger, though, is that thanks to the USDA's loosey-goosey administration of the term "organic," it will eventually become meaningless. For example, when most people think of organic milk, they think of the Horizon brand. When you're looking for organic milk, they're omnipresent, literally dwarfing every other brand combined.
Read the story on a carton of Horizon milk and you find yourself in the land of small farmers whose cows graze on open pasture lands maintained with sustainable practices -- the essence of organic. But Horizon is owned by Dean, a huge company that has already absorbed brands such as Silk, Land-O-Lakes, Pet Evaporated Milk, MeadowGold, and Alta Dena, among others. And an expose by the Cornucopia Institute revealed that Horizon is anything but a small idyllic farming cooperative. In addition to being massively large, Horizon uses farm-factory techniques penning up as many as 4000 cows in tight rows for milking assembly-line style. And yet, the USDA allows them to promote themselves as organic, even though their production methods totally contradict the spirit of the law, if not necessarily the letter.
Ultimately, if the word "organic" loses all meaning, we will have to invent a new term to re-describe the purity we have lost. Even as I write this, the best small organic companies are being bought up en masse by large corporations looking to exploit the value of their new brand's organic credibility, even as they work to ever cheapen its cost…and consequently its nutritional value. Think I'm exaggerating? Then know that mega-corporations like Heinz, PepsiCo, and Kraft are busily gobbling up small, dedicated, organic food producing companies. The organic name brands you once relied on are not necessarily as reliable as they once were. You can get a graphic depiction of who owns what at http://www.cornucopia.org/who-owns-organic/.
PS: And let me throw it out there now, in case "organic" ultimately loses all meaning. We could call it "Integral Farming" -- for farming that produces crops that are grown in an integral manner and that "contain everything essential for life and required for their own completeness." We could define it the way we once defined organic farming and organic foods, before the words were co-opted. Products could be labeled "organic" to satisy the government and "Certified Integral" to satisfy ourselves. The question is: who will define the term, and who will certify farms and products -- until such time as the USDA decides to steal that term too?