13 Sep 2012 Organic food isn’t healthier or safer, new Stanford study finds
Does an organic strawberry contain more vitamin C than a conventional one? A new study by Stanford researchers has added fuel to a debate about the differences between organic and conventionally grown foods. Stanford University scientists have weighed in on the “maybe not” side of the debate after an extensive examination of four decades of research comparing organic and conventional foods.
They concluded that fruits and vegetables labeled organic were, on average, no more nutritious than their conventional counterparts, which tend to be far less expensive. Nor were they any less likely to be contaminated by dangerous bacteria like E coli.
The researchers also found no obvious health advantages to organic meats.
Conventional fruits and vegetables did have more pesticide residue, but the levels were almost always under the allowed safety limits, the scientists said. The Environmental Protection Agency sets the limits at levels that it says do not harm humans.
“When we began this project, we thought that there would likely be some findings that would support the superiority of organics over conventional food,” said Dr Dena Bravata, a senior affiliate with Stanford’s Center for Health Policy and the senior author of the paper, which appears in the latest issue of the Annals of Internal Medicine. “I think we were definitely surprised.”
The conclusions will almost certainly fuel the debate over whether organic foods are a smart choice for healthier living or a marketing tool that gulls people into overpaying. The production of organic food is governed by a raft of regulations that generally prohibit the use of synthetic pesticides, hormones and additives.
The organic produce market in the United States has grown quickly, up 12 percent last year, to $12.4 billion, compared with 2010, according to the Organic Trade Association. Organic meat has a smaller share of the American market, at $538 million last year, the trade group said.
The findings seem unlikely to sway many fans of organic food. Advocates for organic farming said the Stanford researchers failed to appreciate the differences they did find between the two types of food — differences that validated the reasons people usually cite for buying organic. Organic produce, as expected, was much less likely to retain traces of pesticides.
Organic chicken and pork were less likely to be contaminated by antibiotic-resistant bacteria.
“Those are the big motivators for the organic consumer,” said Christine Bushway, the executive director of the trade association.
The study also found that organic milk contained more omega-3 fatty acids, which are considered beneficial for the heart.
“We feel organic food is living up to its promise,” said Sonya Lunder, a senior analyst with the Environmental Working Group, which publishes lists highlighting the fruits and vegetables with the lowest and highest amounts of pesticide residues.
The Stanford researchers said that by providing an objective review of the current science of organic foods, their goal was to allow people to make informed choices.
In the study — a meta-analysis, in which previous findings are aggregated but no new laboratory work is conducted — researchers combined data from 237 studies, examining a wide variety of fruits, vegetables and meats. For four years, they performed statistical analyses looking for signs of health benefits from adding organic foods to the diet.
The researchers did not use any outside financing for their research. “I really wanted us to have no perception of bias,” Bravata said…..