Nutrients and pesticide use are the two topics that concern consumers most when choosing between organic or conventional produce. You may choose organic because you believe it to be healthier for the body or for the environment. You may choose conventional produce because it’s cheaper or because it’s easier to find. It’s important to be well-informed about the choices you make, as sometimes we can follow our intuitions or what we hear from others. Though the decision of what produce you put in your shopping cart is a personal choice, we can often get caught up along the way with confusing information and claims.
There are very few significant differences between organic and conventional produce when we look to overall nutrient composition. Various studies state that across the board, organic and conventional crops have similar levels of micro- and macro-nutrients, including vitamin C, calcium, phosphorus, potassium, total soluble solids, copper, iron, nitrates, manganese, ash, specific proteins, sodium, plant non-digestible carbohydrates, β-carotene and sulphur (link).
- Conventional crops are higher in nitrogen. The primary goal of conventional farming is to generate high yields (the most crops possible on a plot of land), and to do this, a substantial amount of nitrogen is needed. Conventional farmers will apply with a heavy hand chemical fertilizers, which deliver lots of nitrogen in addition to other substances that help plants grow. Compare this to organic farming, which relies on building up nutrients over a larger period of time (link). Organic farmers might choose to use crop residue as a means to help plants grow instead, which does have nitrogen in it, just in less concentrated amounts.
- Organic crops are said to have more magnesium, zinc, phenolic compounds, and “titratable acidity.” Organic soils are “built” by farmers, meaning that they input natural (as opposed to synthesized) materials on their fields over time as fertilizers. Some of these, like limes, sea kelp, or animal manures, are intrinsically higher in magnesium and zinc (link). Organic crops are higher in phytochemicals, evidenced by studies such as 1, 2, 3. Phytochemical quantity is affected by factors such as genetics, maturity, soil quality, diseases and pests, post harvest storage, and processing, according to this article. Yet, it states that it’s hard to pinpoint a true reason why organic crops are higher in phenolic compounds– there’s too many confounds. It is not clear which variables in organic farming systems might have the greatest effect on inducing or promoting the phytochemical content of crops.
Organics are not pesticide free. On the contrary– organic farmers and conventional farmers both use them. And both prefer not to use them if possible, as pesticides are costly. What is interesting to note is that the “dosage” of pesticides used on organic crops is actually higher! Because organic farms are restricted to only using pesticides that are easier broken down by the environment and are unobtrusive to the land and water ecosystems, they frequently need to be replenished. Conventional farmers have free range to use whatever pesticide chemicals they like, synthetic or natural. Organic pesticides tend to be from naturally derived sources. So on this front, organic farming is arguably healthier for our environment.
Given this fact, it seems to follow that organic pesticides would also be less toxic and better for consumer health. While this holds true for the majority, there are a few notable exceptions.
- Rotenone. Rotenone is an example of a natural pesticide that is used on organic farms, yet is far more toxic than many artificial ones (just look at this!). Even synthetic organophosphates, such as Malathion (a chemical used as a pesticide with a dual use as a potent neurotoxin also recognized as Sarin gas) have an upwards exposure limit that is fifty times higher than Rotenone (≤ 0.2mg/kg of bodyweight per day vs Rotenone’s ≤0.004mg/kg of bodyweight per day). And Glyphosate, commonly called Roundup, has an upward exposure of 0.1 milligrams per kilogram a day. This means you’d have to be exposed to 25 times as much Roundup in order to be exposed to the same amount of toxicity as Rotenone. There are countless other synthetic chemicals that pose less of a toxicity risk than this one that is of our own earth (link).
- Pyrethrins. This class of pesticides are derived from chrysanthemums. They’re approved for use in organic farming due to their minimal environmental impact, but they far surpass Rotenone in their toxicity.
But… are people being exposed to similar amounts of synthetic and natural pesticides? As mentioned above, both conventional and organic growers only use them if they have to as they are expensive. The benefit of traditional synthetic pesticides is that they’ve been engineered to be more effective at lower doses (link).
A recent study comparing the effectiveness of a blend of a rotenone-pyrethrin mixture versus a synthetic pesticide known as imidan showed that 7 applications of the organic mixture were required to obtain the level of protection by 2 applications of the synthetic (link). In another study that compared these same two pesticides to see their effectiveness on apple yields showed that with six to seven sprays throughout the growing season of the natural mixture provided a 75 percent yield on apples. With the synthetic pesticide, they were able to get a 90 percent yield with four sprays (link). What we can take from these studies is that organic produce could have just as much or more pesticide on it.
Now that we understand the presence of the pesticides on our crops, we need to ask the question: are these truly dangerous amounts? Just because both organic and conventional produce can have lots of pesticides, it doesn’t say much about if it will cause consumers harm. It’s been said that the methodology for analyzing which fruits and vegetables deserve a spot on the “Dirty Dozen” list is flawed. In addition, the actual pesticide levels on fruits and vegetables is not compared to the Environmental Protection Agency’s guidelines for exposure limits.
To sum it up, most Americans consume doses of pesticides that are hundreds of times less than the EPA exposure limit. In the case of apples, the number 1 ranked on the “Dirty Dozen” list, you’d have to eat nearly 800 apples in one day in order to approach the EPA’s exposure limit (link). For other produce, you’d have to eat even more.
Cumulative effects may be present in certain pesticides, but consumers won’t be ingesting anything close to exposure limits. There is lots of information and studies that show that what we’re exposed to is very low, much lower than what would even be required to have a small health concern.
Did you know that fruits and vegetables make their own toxins as well? Flavonoids, hydrogen peroxide, and formaldehyde are all natural toxins found within plants. Americans consume far more of these natural these toxins than we do the ones that come from pesticide use (link).
In spite of this, we are advised fruits and vegetables, regardless of if they’re grown on an organic farm or a conventional one. Because although there may be high levels of toxins found in these plant foods, they are still exceptionally good for us. So much so, that their benefits outweigh their risks (1,2,3).