Why do consumers buy organic foods?
A new study by Stanford researchers has added fuel to a debate about the differences between organic and conventionally grown foods. The Stanford report, an analysis of 237 studies of organic produce, meats and dairy foods, concluded that organic foods are no more nutritious than their conventional counterparts. Advocates of organic foods, meanwhile, say that the study takes a narrow view of organic food choices, and that most people choose organic because they want to avoid pesticides, hormones and other chemicals used in conventional farming.
Here are answers to some commonly asked questions about the Stanford study and organic foods.
And in some cases, researchers have measured significant differences. A 2010 study by Washington State University scientists found organic strawberries have more vitamin C and antioxidants than conventional strawberries. Organic tomatoes also have more of a type of antioxidant called polyphenols than commercially grown tomatoes, according to a study published in July by scientists at the University of Barcelona.
However, other variables, like ripeness, may influence nutritional content even more. A peach or berry that reaches peak ripeness with the use of pesticides could contain considerably more vitamins than a less-ripe organically grown fruit.
The Stanford study reviewed decades of research to determine whether choosing organic produce, meats and milk would lead to better nutrition generally. They concluded the answer was no. That is, just following “organic” for everything does not bring obvious, immediate health benefits.
Q. I’ve heard organic milk is a better option than commercial milk products. Is that true?
A. Organic milk has risen in popularity in large part because of concerns over bovine growth hormone, used to stimulate milk production on conventional dairy farms. The hormone occurs naturally in cows, and the Food and Drug Administration has argued that use of the hormone does not change the milk.
But producers of organic milk are required to allow their cows to spend a certain amount of time grazing, and that does produce a noticeable effect on the fatty acids in the milk. Compared with conventional milk, organic milk has lower levels of omega-6 fatty acids, which are believed to be unhealthy for the heart in high concentrations, and higher levels of healthful omega-3 fatty acids. The Stanford researchers noted that organic milk does have modestly higher levels of omega-3 fatty acids, based on a few small studies included in the analysis.
Organic Valley, a cooperative of organic farmers, says its organic milk shows omega-3 levels that are 79 percent higher than those in conventional milk, as well as much lower levels of omega-6.
Q. What about pesticides? Is there a health benefit to eating foods grown without them?
A. Organic produce has lower levels of pesticide residue than conventional fruits and vegetables. That said, almost all produce, whether it’s organic or conventional, already contains less pesticide residue than the maximum allowed by the Environmental Protection Agency. It then becomes of a question of whether you are comfortable with the E.P.A. standards. Charles Benbrook, who worked as the chief scientist for the Organic Center before moving to Washington State University last month, said the benefits of organic food, in terms of pesticide exposure, would be greatest for pregnant women, for young children and for older people with chronic health problems. He cites research that looked at blood pesticide levels of pregnant women and then followed their children for several years. The studies found that women with the highest pesticide levels during pregnancy gave birth to children who later tested 4 to 7 percent lower on I.Q. tests compared with their elementary school peers.
Q. Aren’t there benefits to organic eating beyond individual gains? What about the health of farm workers and the health of the planet?
A. The answer to this question is not as clear-cut as one would like it to be.
For farm workers, some pesticides appear to cause some cancers.
Over the past few decades the E.P.A. has banned many of the most toxic pesticides, so presumably the risk to workers is lower now than it was. Many people who buy organic foods say they do so because they are concerned about the health of farm workers.
In terms of the environmental effects of organic farming versus conventional farming, it depends on how you view it. One meta-analysis found that organic farming had fewer environmental impacts per acre. However, because of lower yields from organic crops, the environmental effect of organic produce was actually greater per product shipped.
In addition, there are growing concerns about the role of agricultural antibiotics leading to new antibiotic-resistant strains of bacteria.
What are your reasons for buying organic or conventional food? Do you have more you want to know about the Stanford study or organic eating in general? Join the conversation below, and I’ll be jumping in to answer questions as needed.