The Dairy Divide

Is organic milk really
better for you?

Late last year, the Internet erupted with the news
of a Washington State University study claiming
added nutritional benefits in organic milk as
compared to conventional. This was the long-
awaited silver bullet for the organic food movement,
which has historically lacked substantial scientific
evidence to back up the claim that organic foods are
nutritionally superior to conventional.

Now, that’s not to say that organics aren’t beneficial
across a variety of other spectra; many people
choose them because of their reduced impact
on the environment or because they’re produced
without the use of artificial pesticides, synthetic
fertilizers, antibiotics, or hormones. Others choose
organics because it’s an assurance those foods
won’t contain any genetically modified organisms.
In fact, the whole point of organic food is that it’s
more environmentally sustainable, not that it’s
more nutritious. So, needless to say, this was big
news, even if the study was funded by Organic
Valley, a large farm cooperative that sells organic
dairy products.

In the nationwide study, researchers tested nearly
400 samples of whole milk over an 18-month period
and found that organic milk had a more favorable
fatty acid composition than conventional milk.
The two fatty acids they looked at were omega-6
and omega-3, of which a balance has existed for
millions of years of our evolution, when we got
fatty acids mostly from meat, fish, eggs, wild plants,
nuts, and berries. But over the last century, intakes
of omega-6 fatty acids have dramatically increased
in Western diets as a result of changes in food
technology and agribusiness, while consumption
of omega-3 fatty acids has fallen. The optimal ratio
for humans is near 2:1 omega-6 to omega-3, though
recent estimates put most American diets closer
to the nutritionally undesirable ratio of 15:1. The Washington State study found that conventional
milk had 5.8 omega-6 fatty acids to every one
omega-3, while the amount of omega-6 in organic
milk was closer to 2. The authors concluded from
this that organic milk is indeed a healthier option
for consumers than conventional (remembering that
the figures do not apply to nonfat milk, which strips
away the fatty acids)

However, there was one problem with the study, and
one overlooked conflating detail: grass. Fatty acids
found in milk are derived from two sources: feed
and microbial activity in the rumen of the cow. It
has been well documented that milk from cows on a
grass diet has higher levels of the beneficial omega-3
fatty acids. Most conventional milk comes from cows
that are mostly fed corn, which is high in omega-6s.
But grass-fed conventional milk would carry the
same nutritional profile as an organic diet. This was
actually shown in the study; conventional milk from
grass-grazing cows in Northern California had a
fatty acid composition similar to organic milk. This
all seems a bit confusing. So what are the standards
for organic milk production, exactly?

According to the USDA, these standards require:

  • Access to pasture throughout the grazing season
    (specific to geographic location and climate),
    totaling at least 120 days
  • Diet consisting of at least 30% dry matter intake
    from pasture during the grazing season
  • 100% organic feed when not in grazing season
  • No antibiotics
  • No hormones to promote growth
  • No mammalian or poultry by-products in feed

This means organic-milk-producing cows may or
may not graze on pasture, depending on the time of
year, and they can technically be off it for as much
as eight months if raised in a region with a short
grazing season. Such wide-ranging variability in
feeding and diet formulations has an impact on the
nutritional content of organic milk. In fact, the
Washington State study found that a desirable fatty
acid profile peaked in organic milk from May to
October—the time of year when most organic cows
are outside grazing on live grasses. Those fatty acids
fell in the winter months when cows are moved
inside to feed on grain and stored forage.

So what does this mean for you, the consumer? The
bottom line is that if you’re looking for healthier
milk, you’ve got to do more than just look for an
organic label. Finding milk producers that are
primarily or even 100% grass-fed, such as our
partners Cedar Summit Farm in New Prague, Minn.
and Castle Rock Farms in Osseo, Wis. will offer more
of those benefits than larger operations that graze
their cows less frequently. The Cornucopia Institute,
an organics watchdog keeps a continually updated
scorecard of U.S. dairy operations to help you make
educated choices about where your milk comes from.
They rate organic farms on things like pasture time
and acreage provided to the cows, and tease apart
some of the wide variability in feeding practices
that falls within the national standards of USDA
organic certification. You can find this information
on their website at: cornucopia.org/dairysurvey.

Or just keep it simple
and remember it’s all
about the grass.