Many of us have been feeling guilty for choosing conventionally-grown produce over organic produce in the grocery store because it costs so much less. So you might have been surprised (and a little relieved) to hear that maybe we’re not harming ourselves as much as we thought.
Two weeks ago, the Annals of Internal Medicine published a study with a title that asks “Are Organic Foods Safer or Healthier than Conventional Alternatives?” The next day’s stories about the study, from NPR to major newspapers, all repeated the authors’ conclusion that the answer was no, not really. I disagree.
This post is an attempt to explain why. I spent many years trying to simplify scientific data and concepts in my job as an environmental activist. I wasn’t always successful, because some things are tough to explain in a few words (for me, anyway). I’m not sure I can put this post in the success column, but I hope it will make sense.
The study’s authors, from Stanford University, set out to answer the question they posed by reviewing published studies done to date on human health impacts, data on pesticide contamination, and nutrient data for organic and conventional foods. It was quite an undertaking. But the article I read in the Washington Post made me wonder why the authors were concluding that there was no real difference between organic and conventional foods.
I’ve read a number of risk analysis studies and done some risk analyses of my own. So when I see the word “risk” as it applies to toxic chemicals, I try to figure out what it means in that particular context. The Post reported that “organic produce had a 30 percent lower risk of containing detectable pesticide levels.” Thirty percent doesn’t sound like “no real difference” to me. So I decided to take a look at the study to see what the authors were talking about.
After a couple of weeks mulling over the full study and pieces written about it, I’ve decided that the paper barely begins to answer the question. You simply can’t do it with the research that has been done so far. But it does allow us to come to some conclusions about organic food, and I think the news is good.
My take on it all is:
- You’re much less likely to find pesticides in organic food than in conventionally-produced food. No kidding, right? That’s supposed to be what organic food is about. But the amount of difference surprised me.
- Given what we know about how pesticides are applied, this probably means that you’re avoiding the really nasty pesticides with organic food, even if the organic food you’re eating contains some pesticide.
- The authors’ conclusion that organic food isn’t necessarily better for you ought to be followed by the words “assuming you believe that the outdated way acceptable levels are set for pesticides reflects the true nature of these chemicals and how we eat.” It’s not the authors’ fault that you don’t see those words. Even if they’d agree with me, the paper probably wouldn’t have made it through peer review and publication had they said so.
Now for the specifics.
Despite the fact that pesticides remain in the environment a long time without breaking down and can be transported over long distances by winds, the two-plus decades of organic farming have resulted in significantly less food with pesticides in it than we would otherwise have.
The figure cited in news reports that you’re 30 percent less likely to have measurable amounts of pesticides in organic food is a simple calculation. The authors took the available studies on pesticide residue in organic and conventional foods and counted the number of measurements that showed something as opposed to not finding anything.
I’ve used the words “something” and “anything” deliberately. Almost any time a pesticide is used on fruits or vegetables, some of that chemical remains in the produce. The remainder is called residue. How much residue depends on how much was used this season, how much was still in the soil from previous uses, the length of time between use of the chemicals and harvest, and other factors like weather. The amount of residue is usually small, so there’s a question of whether or not measurement instruments can even detect the residue that’s there. Detection methods are getting better and better with time, but it’s important to remember that, even today, “not detected” doesn’t mean “not there.” Still, it’s the best we can do at the moment.
The Stanford researchers found that while about eight percent of organic food tested had measurable pesticides, nearly 40 percent of conventional food tested did as well. That’s where the 30 percent comes in — it’s the average of the differences between conventional and organic food in the various data.
To my mind, it’s remarkable to learn that only a little more than eight percent of samples of organic food tested had measurable pesticide residue, considering that pesticides can stay in the environment for a long time and have migrated to virtually every part of the globe. I imagine this amount will get even lower with time.
Pesticide residue measurements only tell us part of the story, but it’s logical to think that less pesticide residue translates to other advantages.
As I mentioned, the study looked at whether particular food products had measureable pesticide residue or not. What we don’t know from the 30 percent difference is how large the measurements actually were, which pesticides were found, and whether more than one pesticide was found in a given sample.
Given that we now know that organic foods are much less likely to have measurable pesticide residue, I don’t think it’s a stretch to assume that (a) organic foods would contain less pesticides than conventional foods even if you can measure the residue, and (b) the organic food would probably contain fewer of the really nasty pesticides.
We know that some crops and produce are treated with more than one pesticide, so it follows that some of the 40 percent of conventional food samples probably had more than one pesticide at measurable levels. Since organic foods aren’t treated with pesticides, they’re less likely to have measurable residue from more than one pesticide.
You may think this sounds like speculation on my part, but it’s a logical extension of what the study already told us. And it directly contradicts the authors’ conclusion that the 30 percent difference doesn’t mean that organic food is better for you.
The authors contend that this difference doesn’t mean much for your health because the pesticide levels found were (mostly) well below legal limits. However, those legal limits are set in ways that ignore much of what we currently know about pesticides.
What we do know about the residue measurements, according to the authors, is that very few samples – either conventional or organic – showed contamination over maximum allowable levels. Since the levels of pesticides weren’t high enough to be considered unsafe under current practices, the authors had no reason to say that organic foods were better for you from the standpoint of pesticides.
I’m glad to hear that there weren’t many samples with pesticide levels over the allowable limits, because that’s what the laws are supposed to prevent. But being below the limits doesn’t reassure me, for two reasons.
First, the limits are set for each pesticide and don’t reflect the fact that we probably end up eating more than one pesticide in a given meal, and definitely do over time. We don’t know exactly how these pesticides interact with each other in our bodies, but we know enough that we have to seriously consider the possibility that pesticides in combination are more toxic together than they would be alone. Obviously, more work needs to be done to nail this down, since it’s just one of a myriad of toxic chemical issues that don’t get much study. (It’s important to remember when you hear the words “there’s no evidence…” concerning toxic chemicals, 99.999 percent of the time it means that no one has looked at it, not that we know for sure one way or the other.)
Second, we know more about how these chemicals work than we did when many of the allowable limits were set. We know it takes less of them than anyone could have imagined to cause reproductive health effects, for instance, especially damage to the reproductive systems of fetuses during pregnancy in animal studies. We’re talking about barely detectable amounts here, and even amounts that can’t currently be detected in food residues. While pesticides are reviewed periodically by EPA, EPA doesn’t yet incorporate these very low dose effects into its calculations. I’m positive that in the future we’ll see allowable levels for many chemicals go way down.
I have to say up front that I’m a firm believer in prevention rather than clean-up when it comes to toxic chemicals. It might sound like I’m a glass-half-empty kind of guy, but in my experience, we rarely find that anything in this world is safer than we first thought. When I consider all of these things, this study makes me more convinced that we were right to feel guilty about passing up organic produce after all.
If you’ve stuck with me this far, I imagine you’re asking, “So, isn’t this blog about wine?” Yes, indeed. All this talk about organic food and no mention of organic wine? It would take me another ream of paper to talk about organic certification and wine, and I doubt that any of us has the energy for that. But if you’re looking to drink wine from grapes grown without pesticides, you don’t have to look for the word organic on the label.
I’ve talked about the French AOC wine authorities in previous posts. Besides making rules on naming wines and telling producers how much wine they can make, how the wine has to be made, and what quality designation they can give it, there are also rules about growing the grapes that go into the wine. In the southern Rhône valley, where most of our producers are, wines with a classification above Vin de Table and Vin du Pays are made without synthetic pesticides, herbicides, or fertilizers, and the grape vines aren’t irrigated either. The rules only allow grape growers to apply a fungicide – copper sulfate – if they need to.
Many vineyards don’t use copper sulfate and could probably qualify as growing organic grapes, but they don’t want to get that designation. A year with heavy rains at the wrong time could wipe out the entire year’s production. To keep this from happening, most growers reserve the right to use copper sulfate if it’s absolutely necessary.
So our wines labeled Luberon, Côtes du Ventoux, Côtes du Rhône, Côtes du Rhône Villages, or Rhône cru wines (where you see only the name of the village, like Vinsobres or Gigondas) are made without using pesticides on the grapes and minimal chemical interference. That doesn’t guarantee that there isn’t pesticide residue in the wine, but it certainly makes it more likely.
Add to this that the grapes are grown in poor soil that wouldn’t support other kinds of agriculture, and it gives a picture of sensible farming and land use with or without terms like sustainable, organic, or biodynamic.
This week I’m recommending Domaine Fond Croze Cuvée Romanaise 2007 ($17). It’s classified as a Côtes du Rhône, made from equal parts Grenache and Syrah, with the Syrah aged in oak. No pesticides, just an excellent balance of dark fruit, spice, and leathery/tobacco earthiness. Bruno Long is the third-generation winemaker in his family, and has guided the winery from making the go-to wines for a small village to producing some of the few non-cru wines in the region that earned 90+ points from Robert Parker.
Try the Romanaise with this week’s recipe, a tuna and red pepper mousse that’s really easy to prepare. You can use it as a vegetable dip (with organic vegetables, right? ), spread it on crackers, make elegant crostini, or eat it with a spoon. It’s that good. My husband Cy has been making this for years and it’s definitely a crowd-pleaser.
There are only three ingredients: tuna, roasted red pepper, and butter. So it pays to get good quality tuna packed in oil (my favorites are from Italy, Spain, and Portugal) and jarred roasted peppers that aren’t disintegrating (I like Divina brand. You could roast a red pepper yourself, but it’s also a good pantry staple to have around in a jar). The main thing is not to mix the ingredients too much or it will become dense rather than light and fluffy. But don’t sweat it, it tastes good either way.
1 can or jar good quality tuna packed in olive oil (between 5 and 7 ounces), drained, and the tuna flaked into small pieces but not shreds
1 small roasted red pepper, rinsed, patted dry, and coarsely chopped (about ½ cup)
3 tablespoons very soft unsalted butter
Freshly-ground black pepper
Put the tuna and red pepper pieces in the bowl of a food processor fitted with a steel blade. Cut the butter into four pieces and distribute them over the other ingredients, then grind some black pepper over the top. Pulse the mixture until it’s all just blended and the tuna and red pepper are in small pieces. Remove the blade. Taste for salt, if it needs some sprinkle the salt over the top and gently fold it in with a rubber spatula. Serve at room temperature.
Add-ins: Gently fold in a little finely-diced red onion, or about 1/4 cup drained and rinsed small white beans or chickpeas if desired.
Crostini: Mound the mousse on thin slices of toasted baguette. Top with thin strips of roasted pepper, or toasted pine nuts or walnut pieces, or a sprinkling of coarse salt.
Roll-ups: Brush one side of a flour tortilla with olive oil, heat in a non-stick skillet oil-side down until it just browns a bit. Remove the tortilla to a plate. Spread the mousse on the unbrowned side, then roll the tortilla up. Slice ½-inch thick and serve.