Is Organic Food Provably Better?
Is Organic Food Provably Better?
By MARIAN BURROS
New York Times, July 16, 2003
In the debate over whether organic food is better than conventionally raised food, advocates for organic produce say it contains fewer harmful chemicals and is better for the earth, and some claim that it is more nutritious.
And recent preliminary evidence suggests that the levels of certain nutrients, especially vitamin C, some minerals and some polyphenols - naturally occurring antioxidants that may help bolster the immune system - are higher in organically grown crops.
As a result of this preliminary evidence and the Agriculture Department's adoption in 2000 of standards for organic foods, the Organic Trade Association has created the nonprofit Center for Organic Education and Promotion to finance research that could verify what small-scale research may suggest: organic food may provide greater health benefits than conventional food.
"We want to take the knowledge to the next level until there is a solid body of research that we can stand behind," said Katherine DiMatteo, executive director of the association. "There needs to be more rigor."
A study in the January 2003 Journal of Agricultural and Food Chemistry found 52 percent more ascorbic acid, or vitamin C, in frozen organic corn than in conventional corn, and 67 percent more in corn raised by sustainable methods - a combination of organic and conventional farming. Polyphenols were significantly higher in organic and sustainable marionberries compared to conventionally farmed ones.
A three-year study in Italy, reported in the August 2002 issue of the same journal, found higher levels of polyphenols in organic peaches and pears, and about 8 percent more ascorbic acid in organic peaches.
And a study in the February 2002 European Journal of Nutrition found more salicylic acid in organic vegetable soup than in nonorganic soup. Salicylic acid is responsible for the anti-inflammatory properties of aspirin, and bolsters the immune system.
Critics say these studies were poorly done, are biased and dealt with tiny differences in nutrients.
Alex Avery, director of research and education at the Center for Global Food Issues at the Hudson Institute, who frequently disputes claims for the positive health benefits of organic farming, said the marionberry and corn study did not involve proper statistical analysis and that the data came from a single year and a single farm.
"This is a very, very shaky basis, given the differences that can occur," Mr. Avery said.
Dr. Diane Barrett of the University of California at Davis, a researcher on the study, said: "We acknowledge it's very preliminary data." She added: "It was a real-life look at what happens in a grower's field. We did not expect such differences among organic, sustainable and conventional farming. We see it as an open door to doing more controlled studies at the university."
Charles Benbrook, former executive director of the Board on Agriculture at the National Academy of Sciences, who is a consultant on the impact of agricultural systems and technology on food safety and the environment, said the study's conclusions were not surprising.
"This study extends and reinforces findings in earlier research," he said, referring to reports indicating that when plants are not treated with pesticides and are attacked by insects their levels of antioxidants rise to limit damage.
"But it is new because it uses different crops under different circumstances. The study may have flaws, but it is a legitimate study."
Mr. Avery said the Italian study showed very little difference in nutrient levels. "I don't think you are going to find any health differences," he said.
And while scientists emphasize the importance of polyphenols and other antioxidants, particularly because they might help fight cancer, Mr. Avery said: "No one has a clue how much phenolics anyone needs to consume. Anyone who claims nutritional benefits from higher or lower phenolics doesn't understand."
Dr. John Reganold, a professor of soil science at Washington State University, who has conducted research with organic farming systems systems, described the Italian study as good, and said the results were valid. The higher levels of vitamin C, Mr. Reganold said, are "biologically significant."
In 2001, the Soil Association of England, which sets organic standards, asked Shane Heaton, a nutritionist, to analyze available studies on nutrient differences between organically and conventionally grown food.
He looked at 99 studies and discarded 70 because, he said, they examined growers who did not use certified organic practices, did not make relevant comparisons or were of insufficient duration.
He found that in 14 studies of minerals, 7 showed a "trend toward mineral contents" in organic foods, while 6 showed inconclusive or inconsistent results and 1 showed a higher mineral content for nonorganics. For vitamin C, 7 of 13 studies showed significantly higher levels in organics; they ranged from 6 percent to 100 percent. Six of the studies showed inconsistent or insignificant differences.
Mr. Avery said Mr. Heaton's study was tainted because of the Soil Association's interests.
"A number of research trials time and time again have not found any significant differences," he said. "You need very large, carefully designed and carefully controlled studies to prove that there is a difference because of large natural variability."
Pressed to be more specific, Mr. Avery whose organization has received financing from Monsanto, DowElanco and the Ag-Chem Equipment Company, which are involved in conventional agriculture and biotechnology, did not offer further criticism.
Mr. Heaton said other researchers had reviewed his work and said it demonstrated "important differences between organic and nonorganic produce."
Dr. Joseph Rosen, a professor of food science at Rutgers, said the conclusions of the studies Mr. Heaton had focused on were less consistent than Mr. Heaton had claimed.
Dr. Rosen said there were only two studies on phytonutrients - naturally occurring antioxidants - and only one showed higher levels in organic food.
Actually, there are five studies in Mr. Heaton's report; four of them showed significant difference in phytonutrients.
Dr. Marion Nestle, chairwoman of the department of nutrition, food studies and public health at New York University, said that because there is so much variation in the soil, the amount of sun and rainfall, "It is difficult to compare findings of different studies."
But she said of Mr. Heaton's study: "The investigators have gone to a lot of trouble, and there is no reason to disbelieve it." His findings, she said, "are consistent with studies coming out now on nutrients, phytochemicals and pesticides."
The debate is far from resolved.
Organic foods, Mr. Avery said, "are clearly no safer, no more nutritious, no more healthful - there are zero advantages for consumers."
Dr. Nestle said, "I don't think there is any question that as more research is done, it is going to become increasingly apparent that organic food is healthier."