Organic Food Offers No Advantage in Nutrition
Sep. 05, 2012 - If you buy organic food because you think it's more nutritious, you might want to save your money. New research found no consistent differences in vitamin content or health benefits between organic and conventional foods.
Researchers at Stanford University analyzed more than 200 studies of organic vs. conventional foods. Of the total, 223 examined the nutritive value or safety of organically and conventionally grown foods and 17 looked at any health benefits in people eating organic vs. conventional foods.
Although the researchers didn't note any nutritional differences between organic and conventional foods, they did conclude that organic produce was 30 percent less likely to be contaminated with pesticides and that organic chicken and pork appeared to cut exposure to antibiotic-resistant bacteria. But the amount of pesticides found on conventional fruits and vegetables fell within allowable limits.
"We didn't find strong evidence that organic food was significantly more nutritious or healthier," says study author Crystal Smith-Spangler, M.D. "And similar levels of both types are contaminated with bacteria," such as E. coli, which can be deadly.
Organic products are generally grown without synthetic pesticides, fertilizers, irradiation, or chemical food additives and without routine use of antibiotics or growth hormones. Organic livestock are offered freedom of movement and access to the outdoors and are fed pesticide- and animal byproduct-free organic feed.
Organic foods also often cost twice as much as conventional foods, but many people have switched to organic. Sales of organic foods rose from $3.6 billion in 1997 to $26.7 billion in 2010.
"We can't exclude the idea that some organic practices may increase nutrient levels ... or increase or decrease bacteria," Dr. Smith-Spangler says. "But at the market you don't often get to look at the organic practices used. Many studies mention that other factors can influence nutrient content, such as ripeness, season, and storage practices."
And, she adds, although the study didn't find significant nutritional differences between the two types of foods, people may turn to organic foods for other reasons. "They may be concerned about the environment, animal welfare practices, or taste, and we weren't evaluating that."
The study was published in this week's Annals of Internal Medicine.
Fruits, vegetables, grains, dairy products, and meat can all be certified as organic if they meet FDA requirements for growth, handling, and processing.
Here is what "organic" really means:
- Compost and manure are used instead of chemical fertilizers.
- Special insects and birds are used instead of insecticides to reduce pests and disease.
- Crops are hand-weeded or rotated to reduce weeds instead of using chemical herbicides.
- Animals are fed only organic products, allowed access to the outdoors, and not given antibiotics or hormones.
In order to be certified organic, 95 percent of a product's ingredients must be organic. Some products, such as eggs, fruits, and vegetables, can claim to be 100 percent organic. Product labels may read "made with organic ingredients" if they are at least 70 percent organic. The terms "hormone-free," "free-range," and "all-natural" may be important to you, as well, but they aren't the same as organic.
Always talk with your health care provider to find out more information.