An analysis by Stanford University researchers has found that organic foods are no more nutritious than conventionally-grown foods.

That doesn't mean that there aren't good reasons for people to buy organic. It just means that the nutritional content of the food isn't one of them.

For their Meta-Analysis, the researchers looked at 237 published studies, 223 of which compared the nutritional content or the level of bacterial, fungal or pesticide contamination of various foods--fruit, meat, vegetables, grain, milk, poultry and eggs--that were grown conventionally to those grown organically.

There was no consistent difference found in the vitamin content of organic and conventional produce or in the fat or protein content of organic and conventional milk•

The researchers did not compare the long-term health effects of eating organic food to those of eating conventional food; they were unable to find any studies on that topic.

Nutritionally, organic and conventional foods were virtually identical. The only nutrient that was significantly higher in organic produce was phosphorus, a nutrient that very few people are deficient in. There was no consistent difference found in the vitamin content of organic and conventional produce or in the fat or protein content of organic and conventional milk, though a few studies did suggest that organic milk contains higher levels of omega-3 fatty acids than conventionally produced milk does.

The researchers do point out that specific organic practices may make certain foods healthier. Organic produce was 30% less likely to be contaminated with pesticides than conventional fruit and vegetables. And organic chicken and pork appeared to reduce exposure to antibiotic-resistant bacteria. But nutritionally speaking, an apple is an apple, whether it's grown organically or not.

Organic food is produced without using most conventional pesticides, petroleum-based or sewage sludge-based fertilizers, bio-engineering, or ionizing radiation. Organic meat and poultry, as well as eggs and dairy products, come from animals that are given no antibiotics or growth hormones. The actual FDA regulations on which farming practices and foods qualify as organic are rather complex.

The study did not address the environmental impact of organic versus conventionally-raised foods or the likelihood of exposure to carcinogens. Organic farmers feel that not using pesticides and other agricultural chemicals offer many health and social benefits. For one thing, they stop these chemicals from polluting water and contaminating the environment. They think this is value that you can't put a price tag on. Others view organic farmers as Luddites who produce very expensive food inefficiently. The current study isn't likely to change the views of people in either camp. It should stop them arguing about whether organic food is more nutritious and help shift the discussion back to essentials: whether organic farming and buying organic food makes sense or not.

An article on the analysis appears in the Annals of Internal Medicine.