After the sustainability-nutrition program I put together for Pow back in the spring, I feel like I still have some justice to do on the topic of organic foods. So here I'll put together a list of pro's and con's based on some of Michael Pollan's wisdom.
The organic food industry is precisely that: an industry. And with an industry in America, it was virtually impossible for for the idealistic philosophical values originally instilled in the term "organic" to be saved. And even though the USDA finally agreed to put forth guidelines that organic gurus could live with, they are still not the best, and certainly not what many people envision when they think of "organic." Factory farms can be organic, which means the animals are still cooped up indoors, being fed "organic feed," except might have a small door that leads to a narrow patch of grass that they can access for the last 2 out of 8 weeks they are given to live. And the animals that are allowed outside, such as cows, are fed grains in a "dry lot - a grassless fenced enclosure," instead of being allowed to graze on grass (the natural way).
Pollan brings to light quite a few seemingly oxymoronic phrases, such as "processed organic food." Yet it exists, food additives and synthetic chemicals and all. Essentially, the USDA found it easier to accept a list proposed by the growers themselves as standards than to do the legwork on its own and come up with more wholesome standards. And new studies are emerging linking pesticides (especially the organophosphate insecticide chlorpyrifos - currently used on corn, soy, wheat, and many fruits and vegetables - to ADHD, obesity, diabetes, and learning disorders.
In addition, since most organic crops in this country are mass produced in the same way as their conventional counterparts, they are grown in monoclones, while historically varying up the fields with diverse crops is better for the soil. Growing the crops on such a large scale also depletes the soil of nitrogen, which means more nitrogen has to be added to the plants later (as opposed to smaller farms, where nitrogen-fixing bacteria take care of the problem). And the heavy tillage (done by migrant workers, no doubt) required of organic fields (to get rid of weeds the old-fashioned way, instead of chemicals) reduces the biological capacity of the soil "as surely as chemicals would."
In many respects, organic farming is still better for the environment and people's health than conventional means. Thousands of acres of farmland have been converted to organic farms within the last decade or two, which has eliminated hundreds of thousands of pounds of pesticides and petrochemical fertilizers. Earthbound, one of (if not) the biggest organic company, even uses biodiesel fuel (which is of questionable benefit). So undoubtedly, as organic farmer and founder of Cascadian Farm Gene Kahn argues, "Big Organic" (industrialized organic) is a better alternative - "Big Organic" is more effective than "Little Organic" (small farms) would be at converting the US's dependence away from the industrial food market (using leftover military weapon chemicals on our food).
As for nutritional quality, the USDA contends that "all carrots are created equal" and does not do a significant amount of research to determine if organic foods are more nutritious than conventionally grown produce. But a study done at UC Davis (J. Agric. Food. Chem. vol. 51 no. 5, 2003) found that organically grown produce had more vitamin C and polyphenols. This may be because plants grown organically have to work harder to defend themselves against pests and so need to produce these substances (which also happen to be good for humans), while plants grown with chemicals are given substances to protect themselves (which happen to be harmful to us) and so don't need to produce the polyphenols.
Even so, it still depends on the soil the crops are grown in - plants grown in soils with more nutrients will have more nutrients in them. And another thing - organic plants may have more flavor ("since they're not pumped up on synthetic nitrogen, the cells of these slower-growing leaves develop thicker walls and take up less water," and less water means more sugar and more concentrated flavors).
With that said, I think organic foods are a better alternative to conventional, but still not ideal. They are a good way to support the growth of organic farms in relation to conventional farms, but if you want true organic foods (with less food mileage, consuming less fossil fuel energy), I recommend going to a nearby farmer's market or growing them yourself (it's becoming more popular - see here: http://www.washingtonpost.com/wp-dyn/content/article/2008/08/02/AR2008080201397.html). Small farms are more productive than big farms, anyway, in terms of the amount of food produced per acre.
Here's some more information about conventionally grown produce:
(Another option is to use a product such as Veggie Wash, http://www.veggie-wash.com/)
Highest in pesticide residue:
Peaches, apples, sweet bell peppers, celery, nectarines, strawberries, cherries, pears, grapes (imported), spinach, lettuce, potatoes
Lowest in pesticide residue:
Papayas, broccoli, cabbage, bananas, kiwi, sweet peas (frozen), asparagus, mangoes, pineapple, sweet corn (frozen), avocados, onions
(Source: Today's Dietitian, April 2008)
Here are some more websites to check out:
Scientific Findings About Organic Agriculture: http://www.leopold.iastate.edu/organic/
Where do your fresh fruits and vegetables come from? http://www.leopold.iastate.edu/resources/fruitveg/fruitveg.php
More studies: http://www.leopold.iastate.edu/research/grants/completed_grants.htm#2008