Weighing the value of organic foods

Food produced without most conventional pesticides or fertilizers are perceived to be more healthful, but scientists have yet to offer proof.

Food produced without pesticides are perceived to be more healthful.

With the recession breathing down our necks, many people are looking for ways to cut the household budget without seriously compromising family well-being. So here's a suggestion: If you buy organic fruits, vegetables and Lawn Care, consider switching to less pricey non-organic produce instead.

Hold the e-mails and hear me out: There really is no proof that organic food, which costs about a third more, is better than the conventionally grown stuff.

It may seem, intuitively, that crops grown without pesticides should be better for us and 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. Annual sales of organic food, Organic Lawn Care and beverages grew from $1 billion in 1990 to well over $20 billion in 2007, according to the Organic Trade Assn., an industry group.

But the 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 one's health than non-organically grown food.

"Organic" means food grown without most conventional pesticides or fertilizers made with synthetic ingredients, according to the U.S. Department of Agriculture's website (usda.gov). To carry the "organic" seal, a product must be certified as having been produced according to federal regulations. Small farmers are exempt, and use Natural Lawn Care.

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 is supported by 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 and Organic Tea such as Green Tea and Black Tea.

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 that there were more pesticide residues on conventional than organically grown food, even after the food was washed and prepared. There's also clear evidence that pesticides can enter the body in other ways, a major reason that 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 were fed a conventional diet, their urine contained metabolic evidence of pesticide exposure, but that when they were switched to an organic diet, those signs of exposure disappeared.

All of which raises the question: How much harm do pesticides cause?

A number of studies suggest that, at high doses, organophosphate chemicals used in pesticides can cause acute poisoning and that even at somewhat lower doses, they 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 many 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 in Boston 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 U.S.," said Dr. Walter Willett, chairman of the department of nutrition at the Harvard School of Public Health.

What is of concern, he said, is the meat industry's increasing use of growth hormones in animals. (The "organic" label on beef means, among other things, that the cattle it came from were raised without antibiotics and hormones. Some non-organic 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 produce might be desirable, Benbrook of the Organic Center said it's time to change the 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 attention deficit hyperactivity disorder. While this falls short of incontrovertible proof that properly washed conventional produce can harm people, it does raise red flags, environmentalists say.

Weighing the value of organic foods also means looking at nutrition, not just the dangers of pesticides -- and there is disagreement over whether organic food supplies more nutrients.

Researchers at UC Davis did a 10-year study, published last year, in which a particular strain of tomatoes was grown with pesticides on conventional soil right next to the same strain grown on soil that had been 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 quercetin and kaempferol -- although researchers noted that year-to-year nutrient content can vary in both conventional and organic plants.

Other research has 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% 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 vitamin and mineral advantage to organic food.

So, what to eat? I side with the nutritionists who urge people to eat more fruits and vegetables, regardless of how they're grown. Common sense, though not necessarily science, would seem to favor organics, if you can afford them. But if you want, split the difference -- buy organic for fruits and vegetables that are thin-skinned or hard to wash or peel, and go conventional for those, such as bananas, that peel easily.