Cow eating grass in pasture.
March 7, 2018

Grass-fed Milk Healthier Than Conventional?

 |  By: Jim Dickrell

A new study involving the University of Minnesota (U of M), John Hopkins University and universities in England, Australia and Denmark suggests cows fed 100% organic grass and legumes produce milk with 147% more omega-3 fatty acids and 52% less omega-6 fatty acids than conventional milk.

Grass-fed organic milk also has 36% less omega-6 than organic milk produced feeding some grain and concentrates, typically 20% of the ration.

Consuming too much omega-6 and too little omega-3 can increase the risk of cardiovascular and other metabolic disease, say researchers associated with the study. The U of M study analyzed nearly 1,200 milk samples taken over three years from on-farm bulk tanks prior to processing. All the milk came from Organic Valley dairy farms. Besides the U of M and John Hopkins, New Castle University in England, Southern Cross University in Australia and Aarhus University Hospital in Denmark also participated.

The study, however, likely will add to the confusion in the dairy case over which type of milk is healthier.

Though the percentage increases in omega-3 levels with grass feeding seem impressive, the actual levels reached are still far short of what is needed to show a human health benefit, says Mickey Rubin, the National Dairy Council’s vice president of nutrition research. “You’d be really hard-pressed from a human health perspective to show a benefit from grassfed milk versus other dairy products,” he says.

Even doubling the amount of omega-3 in milk from grassfed cows wouldn’t be even close to what you’d see by consuming omega-3 supplements, such as fish oil, says Rubin. “The difference [in omega-3 levels from grassfed milk] is so small that it would be difficult to demonstrate a human health risk or benefit,” he says.

Fairlife introduced its own version of milk with higher omega-3 levels March 2. Fairlife’s DHA Omega-3 whole milk adds 125 milligrams of DHA (docosahexaenoic long chain fatty acid) per serving, roughly the same level of total omega-3 as grass-fed milk in the U of M study. (Note: DHA is a form of omega-3.)

The difference is that in the Fairlife DHA milk, DHA was actually added to the product so you know what you’re getting with each glass you consume, says Rubin. In grassfed cows, the response can be much more variable.