Pullman, WA—Organic milk tends to contain preferable ratios of omega fatty acids to those found in conventional milk, according to an analysis performed by a research team from Washington State University. The study is hailed as the first large-scale, nationwide comparison of the two types of milk, as nearly 400 samples were tested over an 18-month period.

Some scientists believe that the ratio of omega-3 fatty acids to omega-6s is important for heart health, with higher relative amounts of omega-6s correlating with more risk. The study found conventional milk had an average omega-6 to omega-3 ratio of 5.8, while organic milk came in at 2.3. Omega-6s have often been linked with inflammation, while omega-3s are noted for their various health benefits.

The superior ratios found in organic milk may mean improved inflammatory balance, according to study co-author Donald R. Davis, Ph.D., Center for Sustaining Agriculture and Natural Resources at Washington State University at Pullman. “The increased ALA and other omega-3 fatty acids in organic milk favor a more natural and better regulation of needed inflammatory processes,” says Davis.

The underlying reason for these nutritional differences likely lies in the diets cows are given. Organic dairy farms usually afford cows the opportunity to graze on grass and legume forage, which has been shown to promote cow health and improve the fatty acid profile in dairy products, according to the study. In contrast, Davis explains that conventional, high-production dairies usually rely on grain-based ‘‘total mixed rations’’ for cow feed.

Conventional milk from one region used in the study actually had an omega profile similar to organic milk, which the study attributes to the fact that those conventional  farms graze cattle for over 250 days per year. “Our findings from the atypical far northern California region show that much can be achieved without the additional requirements and costs of organic certification, although pasture is not so easily and cheaply available in most other areas,” Davis says.

The study also examined ways that adult women might reduce their omega-6 to omega-3 ratio, which is typically between 10- and 15-to-1 in Western diets. These included switching to organic dairy products from conventional, eating more dairy and avoiding some foods that are high in omega-6s. The study also found organic milk compares favorably with fish in terms of omega-3 ALA content, though it is not a significant source of the omega-3 DHA found in fish.

The study’s lead author was Washington State’s Charles M. Benbrook, and it was published in the online journal PLOS ONE.

Published in WholeFoods Magazine, February 2014 (online 12/20/13)