MELISSA BLOCK, HOST:
Say you're at the store, and you reach into the dairy case. There's organic milk, or you could go for the regular. There's a big difference in price. So is there any reason to pay more? Well, fresh research published in the journal PLoS ONE could help you make up your mind. NPR's food and health correspondent Allison Aubrey joins us to talk about it. And Allison, what are the results from this new study?
ALLISON AUBREY, BYLINE: Hi there, Melissa. Well, the headline here is that this study finds that organic milk has a significant nutritional advantage over conventional milk, and it has to do with differences in the amount of omega-3 fatty acids they contain.
BLOCK: And why would omega-3 fatty acids be so valuable?
AUBREY: Well, they've been shown to help promote brain health, help fend off inflation. They can, for instance, help lower triglycerides, a type of fat in our blood. And the evidence suggested that they cut the risk of heart disease in type 2 diabetes. Now, most people think of omega-3 fatty acids and immediately think of fish, which of course, is an excellent source of omega-3s. But it turns out that there're also omega-3s in other foods, including nuts, leafy greens and dairy.
Now, organic dairy farmers have long promoted the idea that there is a benefit to drinking organic milk because it contains more omega-3s. But until now, they just really haven't had much evidence.
BLOCK: And that brings us to the study, which as you say, does seem to show that organic milk does contain more of these omega-3s.
AUBREY: That's right. The researchers compared organic and conventional milk head-to-head. They analyzed about 400 samples over an 18-month period, to account for seasonal differences. And the samples were taken from, you know, all different parts of the country. And they found that organic milk had about 62 percent more of the heart healthy omega-3s, compared to conventional milk.
And the lead researcher at Washington State University, who I talked to about the study, said - you know, he was quite surprised. He didn't expect such a big difference.
BLOCK: And was there any explanation for the finding why organic milk would have significantly higher levels of these omega-3s?
AUBREY: Sure. It really comes down to watch what the cows were eating. Organic milk is produced from cows that spend a lot more time out on pasture, and they're munching on grasses and legumes. And these greens are rich in omega-3 fatty acids. So as a result, the milk they produce has more omega-3 fatty acids.
On the other hand, conventional milk is more likely to come from cows that spend most of their time in barns or confined. Instead of grazing, they are fed a diet that contains a lot of corn, which has very little omega-3s. So that's the basic difference here.
BLOCK: Well, this has been a big debate - right, Allison? - in the food world. Do organic products and, in this case, dairy products really provide a clear nutritional benefit? Does this study give you an answer to that?
AUBREY: That's right. I mean, I think if you're asking broadly are they showing nutritional benefits for buying organic all the time, no. But if you're looking at the issue of milk, I think the study shows that yes, there's a benefit in terms of getting more omega-3 fat acids from organic milk, compared to conventional milk.
But you know, I should say that there's a trade-off here because in order to get all these extra omega-3s, you've got to drink whole milk. And you know, if you opt for the low-fat dairy - say, 1 percent fat -you've skimmed off most of these omega-3s. So the question is, you know, can you afford the extra calories in fat. If you choose the whole milk, you might need to trim a few calories from elsewhere in your diet.
BLOCK: I have to say, Allison, it did give me pause when I read that the study was partially funded by the organic dairy industry. Are people calling into question these findings and whether they're tainted by that money?
AUBREY: I don't think that people are calling into question the findings - as to whether they were tainted by the funding source - because this is becoming increasingly common in nutrition research. The way this worked is that there was partial funding by organic dairy producers. But the organic dairy producers had no role in the design of the study, or in the analysis. That was all done by the university.
I will say that some people will call into question whether this study is enough to convince people that there are clear health benefits. I think some dairy scientists are saying hey, we'd like to see more research, to show that these extra omega-3s in the organic milk are having some kind of benefit on cardiovascular health.
BLOCK: OK. NPR's Allison Aubrey. Allison, thanks.
AUBREY: Thank you.
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