Comparing apples to organic apples
We'd like to think pesticide-free food is better for us, but scientific proof remains elusive
With the recession breathing down our necks, you may be looking for ways to cut the household budget without seriously compromising family well-being. So here's a suggestion: If you buy organic fruits and veggies, consider going for the less pricey nonorganic produce instead.
I know, I know, abandoning an organic way of life seems unthinkable in this chemical age. But hold the e-mails and hear me out. There really is no proof that organic food, which costs about a third more, is better for us than the conventionally grown stuff.
Yes, it makes sense, intuitively, that crops grown without pesticides should be better for us. It's appealing, politically, to think that food grown the old-fashioned way, by rotating crops and nurturing the soil naturally, would be superior to food that is mass-produced and chemically-saturated.
Many people feel that way. Sales of organic food and beverages have grown from $1 billion in 1990 to well over $20 billion this year, according to the Organic Trade Association, an industry group.
But the unfortunate truth is that, from a hard-nosed science point of view, it's still unclear how much better, if at all, organic food is for human health.
"Organic," for the record, means food grown without most conventional pesticides or fertilizers made with synthetic ingredients, according to the US Department of Agriculture's website (usda.gov). To carry the "organic" seal, a product must be certified by a federally accredited agent as having been produced according federal regulations. Small farmers are exempt.
Prepared food made with organic ingredients also tends to be processed more gently, with fewer chemical additives, said Charles Benbrook, an agricultural economist who is chief scientist at the Organic Center. The nonprofit research group is based in Boulder, Colo., and supported by individuals and the organic food industry.
But the word organic has not been designated as an official "health claim" by the government. Such a designation is used only when there is evidence of significant health benefits - and so far, that evidence is lacking for organic food.
It's clear, however, that conventionally grown food has remnants of pesticides on it. A 2002 study in the journal "Food Additives and Contaminants" showed there are more pesticide residues on conventional than organically grown food, even after the food is washed and prepared. There's also clear evidence that pesticides can get into people, a major reason Environmental Protection Agency regulations exist to keep farm workers from entering recently sprayed fields.
A study by Emory University researchers and others published in 2006 in "Environmental Health Perspectives," a peer-reviewed journal published by the National Institutes of Health, showed that when children are fed a conventional diet, their urine shows metabolic evidence of pesticide exposure, but that when they are switched to an organic diet, those signs of exposure disappear.
All of which raises the question: How much harm do the pesticides cause?
A number of studies suggest that, at high doses, organophosphate chemicals used in pesticides can cause acute poisoning, and even at somewhat lower doses may impair nervous system development in children and animals. But at the amounts allowed by the government in the American food supply? That's where nutritionists and environmental scientists seem to part company.
"We don't have any good proof that there is any harm from fruits and vegetables grown with the pesticides currently used," said Dr. George Blackburn, a nutritionist at Beth Israel Deaconess Medical Center and associate director of the Division of Nutrition at Harvard Medical School. The real issue is to get people to eat more fruits and vegetables, whether they're grown conventionally or organically, he added.
"Keeping herbicide and pesticide levels as low as possible does make sense, although there is no clear evidence that these increase health risks at the levels consumed currently in the US, " said Dr. Walter Willett, chairman of the department of nutrition at the Harvard School of Public Health.
What is of growing concern, he said, is the meat industry's increasing use of growth hormones in animals. Those hormones may be linked to breast cancer in women, he said. (The "organic" label on beef means, among other things, that it was raised without antibiotics and hormones. Some nonorganic beef is also raised without hormones or antibiotics, as noted on its label.)
Even if we don't yet have all the evidence that organic veggies and fruit might be desirable, Benbrook of the Organic Center said it's time to change the old notion that "there's nothing wrong with a little pesticide for breakfast." Over the last two years, he said, "nearly every issue of Environmental Health Perspectives has had at least one new research report" on how pesticides can harm a child's neurological growth, particularly on "brain architecture, learning ability and markers for ADHD, [attention deficit hyperactivity disorder]." While this falls short of incontrovertible "proof" that properly washed conventional produce can harm us, it does raise red flags, environmentalists say.
Weighing the value of organic foods also means looking at nutrition, not just the danger of pesticides - and there is also disagreement over whether organic food supplies more nutrients.
Researchers at the University of California, Davis, did a 10-year study in which a particular strain of tomatoes was grown with pesticides on conventional soil right next to the same strain grown on soil that was certified organic. All plants were subject to the same weather, irrigation, and harvesting conditions.
The conclusion? Organic tomatoes had more vitamin C and health-promoting antioxidants, specifically flavonoids called quercitin and kaemperfol - although researchers noted that year-to-year nutrient content can vary in both conventional and organic plants.
Other studies have also shown nutritional advantages for organic food, according to the Organic Center, which reviewed 97 studies on comparative nutrition. Benbrook, the center's chief scientist, says that although conventionally grown food tends to have more protein, organic food is about 25 percent higher in vitamin C and other antioxidants.
Yet a recent Danish study published in the Journal of the Science of Food and Agriculture showed no vitamins and minerals advantage to organic food.
So, what to eat? I side with the nutritionists who urge us to eat more fruits and veggies, regardless of how they're grown. If you can afford it, common sense, though not necessarily science, would seem to favor the organics. But if you want, split the difference - buy organic for fruits and veggies that are thin-skinned or hard to wash or peel, and go conventional for those, like bananas, that you can peel easily.
Judy Foreman can be reached at firstname.lastname@example.org