Organically Grown Food: Is It Really a Better Choice?
Contrary to popular belief, organically grown produce may not be much more nutritious than conventionally grown produce. But there are other reasons why organic may be a better choice.
"Nine in 10 shoppers who eat organically grown produce rank it as excellent or good in terms of...nutritional value," according to a survey sponsored with the help of the Food Marketing Institute. But do organically grown fruits and vegetables actually have higher levels of vitamins and minerals than conventionally grown produce?
While intuitive logic would suggest they do, "it's a very, very difficult question to answer," says William Lockeretz, PhD, a professor at Tufts University's School of Nutrition Science and Policy who specializes in alternative agricultural methods. "There has been a fair amount [of research] sort of scattered here and there," he notes, "but there isn't any conclusive picture that emerges. The only tendency that seems to be emerging...is that organically grown food often shows a higher vitamin C content. But even with that, you don't get the [same] result every time. The prevailing thought," Lockeretz summarizes, "is that there's no clear difference shown" in the nutrient content between foods grown with different methods.
Good Data Lacking
One of the problems in looking at the issue has been that many of the studies that have attempted to answer the question have been "very crude," according to Joan Dye Gussow, EdD, a professor emeritus at Columbia University Teachers College who has been studying organic foods for more than 30 years.
But it's not necessarily the fault of sloppy researchers. It's hard to conduct a finely executed study on the subject, she says, because there are so many difficult-to-control variables that influence the nutrient content of foods. Among them, the mineral composition of the soil, the degree of exposure to sunlight, the substances used as fertilizers, and the particular variety of fruit or vegetable being examined.
Lockeretz agrees, adding that even the way a food is handled and stored after harvesting could affect its nutrient content.
Nutrition Not the Main Issue
But he, Gussow, and others feel that not having a firm answer on whether organically grown foods have higher levels of nutrients than other foods isn't important. "The United States is already well-fed," Lockeretz points out, "as are other Western nations where people buy organic foods. Consumers of organic foods [in particular] are not hurting for this or that vitamin" because they tend to eat quite well in the first place.
Adds Kate Clancy, PhD, managing director at Winrock International, a nonprofit organization that focuses on agricultural and environmental issues, "Even though I'm a nutritionist, I have always said that I did not believe that's where people's interest should go. There is 'no public health implication' for nutrient differences between organically grown and conventionally grown foods."
Perhaps Gussow puts it most succinctly. "To count minerals and vitamins and stuff it's just dumb. They can stick anything in anything now. They can breed a high-carotene carrot and grow it any way they want," organically or otherwise says Gussow. "To count milligrams of vitamin C—that's not what [it's] about."
Organic Farming and the Environment
So what is it about? Experts say it is about the environment.
"The environmental benefits of organic farming far outweigh any nutritional benefits," notes Molly Anderson, PhD, former director of the Tufts Institute for the Environment. "Probably the strongest environmental benefit [of organics] is in building soil and improving soil quality. The United States, and the rest of the world, is losing topsoil," she points out, "and topsoil is irreplaceable."
"If topsoil is lost and subsoil is exposed," Anderson explains, "it's not as permeable to water. Rain, instead of percolating into the soil [and watering crops], is going to run off." Topsoil is also better aerated than subsoil, she says, which is better for a plant's roots. "Roots have a harder time getting down through subsoil," making it harder for plants to grow.
Moreover, topsoil is "the most fertile part of the soil," Anderson remarks, which means it provides the best nourishment for plants (a different issue from which plants provide the best nourishment for humans). She says letting topsoil erode [by not engaging in enough crop rotation and other helpful practices] is akin to "taking out $100 bills from a bank account, standing on a tall building, and letting them blow away in the wind."
Beyond soil health, proponents of organic farming point to greater biodiversity. In conventional farming, farmers depend mainly on seeds that produce crops that ripen simultaneously and therefore can be harvested more efficiently. But that cuts down dramatically on the variety of fruits and vegetables available. Consider that there used to be more than 400 types of tomatoes. Now there are several dozen. If a plant disease hits, there's less chance that a resistant variety exists to fight it off.
Another benefit of organic farming is protection of the water supply. Without runoff of toxic chemicals in pesticides, water remains cleaner. And finding organic alternatives to synthetic pesticides also means more protection for farm workers and endangered species of animals.
Surprisingly, what seems to fall low on the experts' list of concerns is pesticide poisoning from individual to individual. "Poisoning by pesticide is not that big a deal in the United States," says Lockeretz. "Standards on pesticide residues are stricter than in many other countries."
Imports from other countries might not have the same strict standards," he concedes, but even so, he doesn't feel there's much to be afraid of in terms of pesticides making people sick—unless they're farm workers, particularly in other countries.
Anderson shares his view. "Pesticide contamination is a really, really serious problem for a lot of ecosystems," she says, but "the dangers from pesticide residues are very small to the average consumer." That is, the pesticide issue is much more critical in terms of environmental contamination than in terms of, as she puts it, "which apple you eat."
In a way, it all makes the consideration of whether to buy organic seem less important—or at least less urgent. After all, a lot of the reason people are willing to spend extra money on organically grown produce is that they believe it's more nutritious as well as safer. Yes, they're happy to protect the environment, but what's going on in people's fruit and vegetable drawers, rather than what's going on "out there," is often what drives purchasing decisions.
This is not to say that reducing pesticides in the diet is a bad idea. Recent studies show that commonly used pesticides are almost universally found in children’s blood while they eat conventional foods. A few weeks on an organic diet will eliminate most of these substances from the bloodstream.
While no one has yet shown low levels of pesticides to be harmful, many feel that the “precautionary principle” would suggest that neither young children nor pregnant women should consume foods containing significant pesticide residues. Studies linking pesticide exposures to disorders of aging such as parkinsonism remain controversial, but remind us that the risks of these substances—if there are any significant risks—may still be incompletely researched.
Bypassing these health-related uncertainties, Lockeretz likens the decision to buy organic to choosing between a garment made in a sweat shop and a garment made under better conditions. "The sweat shop clothing could be just as good," he says, "but you don't want it" because of the way it was made, the exploitation involved. It's the same with organics. You're not necessarily getting "a better product," he says. "But the product was made better," without exploitation of the land, farm workers, or wildlife.
Of course, while that doesn't put you ahead in your own kitchen, it does have implications for the health of future generations. When people think about things like soil sustainability, says Clancy, they're "looking into the future for their grandchildren's health." Without soil health, she says, "you can't grow things."
National Organic Program
United States Department of Agriculture
Organic Consumers Association
Dietiticans of Canada
Cohen M. Environmental toxins and health—the health impact of pesticides. Aust Fam Physician. 2007;36(12):1002-4.
Dabbert S. Measuring and communicating the environmental benefits of organic food production. Online. Crop Management. 2006. doi:10.1094/CM-2006-0921-13-RV.
Lu C, Toepel K, Irish R, Fenske RA, Barr DB, Bravo R. Organic diets significantly lower children's dietary exposure to organophosphorus pesticides. Environ Health Perspect. 2006;114(2):260-263.
Last reviewed July 2008 by Maria Adams, MS, MPH, RD
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