Sept. 4, 2012 -- Will eating pricey organic foods make you healthier? Maybe not, a new research review shows.
The review sums up evidence from hundreds of studies of organic foods. It's published in the Annals of Internal Medicine.
Some of the studies compared organic milk, meats, eggs, and produce to non-organic foods. Those studies measured nutrients in the foods as well as contaminants like pesticides and bacteria. A few studies tried to find health differences between people who ate only organic or only non-organic foods.
After weighing all the evidence, the researchers conclude that organic foods don't appear to have more vitamins or nutrients than non-organic foods.
Non-organic fruits and vegetables were 30% more likely to have pesticides than organic fruits and vegetables. But because it's rare for any produce to exceed pesticide safety limits set by the FDA, researchers say it's not known whether reducing an already small exposure makes a difference.
The review also shows that organic meats are less likely to harbor "superbug" bacteria that are resistant to treatment with antibiotics. But researchers say most antibiotic-resistant infections in people come from misuse of antibiotics, not from eating contaminated foods.
In the end, researchers say there's no evidence that people who stick to organic diets are healthier than people who eat non-organic foods.
Not everyone agrees.
Organic or Not?
"There are many different reasons why people choose organic. They may be concerned about animal welfare or the environment. They may do it for taste," says researcher Crystal Smith-Spangler, MD, of Stanford University in California. "I didn't find that nutrition is a major reason to choose organic foods."
Nutrition experts praised the research since it helps to dispel some myths that might make people afraid to eat fresh fruits and vegetables.
"When we're talking about organic, it's really the process, not the product. The process of organic farming is different than conventional farming, but that doesn't mean that the food is bad or unsafe," says Melissa Joy Dobbins, RD, MS, a spokeswoman for the Academy of Nutrition and Dietetics.
Dobbins points out that organic foods can cost twice as much as non-organic foods.
"I don't want that mom who's at the grocery store to feel guilty if she can't afford organic. That mom shouldn't feel like she's making a lesser choice," Dobbins says.
Other experts, however, called the new review misleading.
"The message the general public is going to get is that there are no health benefits from organic foods so why seek it out? Why pay a slightly higher price? I do think the science and facts support some very significant and important long-term benefits," says Charles Benbrook, PhD, a professor of agriculture at Washington State University in Pullman, Wash.
Benbrook points to a similar review published last year that reached the opposite conclusion. That study, by British researchers, found that organic fruits and vegetables contain about 12% more disease-fighting nutrients than non-organic foods. Sticking with organic produce, researchers concluded, would be the equivalent of eating 12% more regular fruits and veggies.
Other experts say the study's conclusions shouldn't change the major reasons that people choose organic foods.
"Nutrition is a lesser concern. It's not the main reason people are buying organic. If you eat organic food, you still need to eat a varied diet, it's not going to solve every health woe. It's marketed to be pesticide-free and antibiotic-free, and that was strongly supported by the study," says Sonya Lunder, MPH, a senior analyst with the nonprofit Environmental Working Group.