Is Organic Milk Better?

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Photo by Fotolia/Jiri Hera
The standard U.S. diet has an imbalance of omega-6 to omega-3 fatty acids. Organic milk has a healthier ratio of these acids than conventional milk, and thus may help reduce the risk of heart disease and potentially cancer.

The first large, nationwide comparison of organic and conventional milk composition, conducted by Washington State University (WSU), found that organic milk has a healthier ratio of omega-6 to omega-3 fatty acids. Many researchers think a higher intake of omega-3 fatty acids (found in meats and dairy products from grass-fed animals, flaxseed, seafood, walnuts and some leafy greens) reduces the risk of heart disease and, potentially, cancer by offsetting the too-high intake of omega-6 fatty acids in the contemporary U.S. diet. The typical U.S. diet contains a ratio of 10:1 omega-6 to omega-3 fatty acids (the imbalance coming from consuming too much processed and fried food, grain oil, seed oil, and meat and dairy from grain-fed animals), while the ratio should be closer to 4:1 or even 2:1.

The 18-month study on the nutritional qualities of milk, published in the peer-reviewed online journal PLOS ONE, compared nearly 400 samples of organic and non-organic whole milk from 14 commercial milk processors. The study found that organic milk has an omega-6 to omega-3 ratio of 2.28:1 — just about perfect in terms of an optimal diet, according to WSU’s explanation of the findings.

The ratio of omega-fatty acids in conventional milk, according to the study, was up to 2.5 times higher, at about 5.8:1. Researchers attributed the difference in the milks to what the cows ate. Most conventional dairy cows’ diets are made up of ingredients high in omega-6 fatty acids, such as corn and corn silage. Organic dairy cows, by standards set by the USDA National Organic Program, spend a minimum of 120 days per year outside on grass pasture and eat forage-based feeds, such as hay, when grass pasture isn’t available.

“The very large increase in omega-3 fatty acids in organic milk — 62 percent higher than in conventional milk — really surprised the whole research team,” says Charles Benbrook, a program leader with WSU’s Center for Sustaining Agriculture and Natural Resources. “These are the heart-healthy fatty acids that play a critical role during pregnancy and lactation, and as a child grows,” he adds. “The magnitude of the difference is the largest I know of between an organic food and its conventional counterpart.”

Consumers should choose whole organic milk to get the most benefit from this difference. “The omega-3 and omega-6 fatty acids are in the fat portion of the milk,” Benbrook says. “Whole milk is about 3.4 percent butterfat, so if you drink 2 percent instead of whole, you’re giving up about half of that benefit.”