For years, consumers have been told to avoid full-fat dairy products. Guidelines from the USDA, the American Heart Association (AHA), the World Health Organization (WHO) and more have warned against consumption of saturated fats.

More recently, the Food and Drug Administration (FDA) has ordered that manufactured trans fatty acids be removed from food due to serious negative health impacts.

But that is beginning to change. The role that fatty acids from whole milk play in negative outcomes to human health is being called into question, and instead, beneficial health effects from some of the 400 fatty acids found in milk – including the trans fatty acids – are being promoted by dairy brands.

Dr. Jana Kraft, department of animal and veterinary science at the University of Vermont, and Allison Unger, a Ph.D. student in Kraft’s lab, along with Elle Andreen of the USDA Agriculture Research Service, presented information on dairy fats during eOrganic’s recent two-part webinar series on the topic. They spoke about the production of fatty acids in cows under different management practices – conventional, organic and grass-fed – the role the cow diet plays in the fatty acid content of the milk produced and the consumer perception of the nutritional properties of milk.

Promoting dairy fat

“We still have to do a lot of consumer education in terms of what whole milk is,” Kraft stated in the webinar. “Most of the consumers do not know how much fat is in whole milk. I think it’s really important to see what’s in [milk] from the consumer side.”

Whole milk, composed of 70% saturated fatty acids, and containing 8 grams of total fat per 8 ounce serving, has been vilified because of the supposed link between saturated fats and cardiovascular disease, metabolic disease and premature death.

“Because saturated fatty acids are that high in dairy products, dairy products are the major contributors to saturated fatty acid intakes in our diets,” Kraft said.

Yet even whole milk is more than 95% fat-free. In the U.S., whole milk is defined as having an overall fat content of 3.25%, or 3.5% in California. The naturally occurring trans fatty acids found in milk are not the same as the dangerous manufactured ones; some of these have known beneficial health effects, and the amount per serving is less than 0.5 grams per serving of milk.

Milk is a unique food product that has more than 400 fatty acids. Only a small portion of these are present in levels above 1%. Fatty acids such as conjugated linoleic acid (CLA) and alpha-linoleic acids (ALA) – a precursor to important omega 6 and omega 3 fatty acids such as EPA and DHA – have been found to be beneficial to human health.

“CLA is a trans fat. Most people don’t know that,” Kraft said. “Trans fats derived from ruminants do not appear to have detrimental effects on human health.”

Some types of fatty acids only occur in dairy and are due to the rumen bacteria’s synergistic relationship to the ruminant. These fatty acids are found in meat and milk, and many have been found to have a positive impact on cardiovascular disease, diabetes, inflammation and pancreatic function.

Cow diet

The amount of fatty acids found in milk is influenced by cow diet. Milk from organic and grass-fed cows have different fatty acid profiles than milk from conventionally managed cows.

“Milkfat profile can definitely be influenced by the composition of the diet,” Andreen explained.

CLA content in milk from pastured cows can be twice as high as that from non-grazing herds, although that will vary with the season. CLA is stable throughout processing and thought to have anti-carcinogenic properties in humans. Increasing CLA content can depress overall milkfat amounts, but the percentage of beneficial fatty acids in the milk overall will be higher.

The ratio of omega 6 to omega 3 in the human diet would ideally be in the 1:1 to 5:1 range. In the U.S., the ratio is skewed as high as 17:1, which causes inflammatory responses. Milk from conventionally fed dairy cows have omega 6 to omega 3 ratios of 5:1 or more. In organic herds, the ratio falls below 5:1, in the anti-inflammatory range.

Many milk brands have begun to advertise the CLA and omega 3 contents of their milk. Consumers are often willing to pay a premium for these dairy products. Unger has been studying the veracity of these claims, comparing 17 organic, conventional and omega 3 enhanced milk brands and assessing them for fatty acid content. One sample per month was taken for 12 months. Results were averaged for each brand over the year.

“Fatty acid content in milk was influenced by retail label,” Unger said.

The study showed that the total saturated fatty acid content of all milk, measured in grams per serving, did not significantly vary by retail label. But other fatty acids were variable in content based on management system.

All conventional brands except one had very similar fatty acid profiles, reported in grams per 100 grams of milk, and results did not vary by season. One conventional brand was an outlier and more closely resembled the profiles of the organic brands examined. That brand was from a dairy farm that grazed the milking herd as much as possible.

Organic brands were more variable in composition, but distinctly separate from conventional profiles. One organic brand stood apart, and that brand was the only 100% grass-fed brand in the study.

Omega 3 fortified milk brands were all organic, and simply added omega 3 fatty acids – typically DHA or EPA – after processing, as a nutritional enhancement. EPA and DHA levels were significantly higher in omega 3 fortified milk brands when compared to conventional and organic milk, indicating that a pasture-based diet itself does not increase these levels.

But pasture alone was found to increase the content of unique dairy-derived fatty acids, known to be beneficial to human health, including CLA.

“Organic milk was the richest source of unique dairy-derived fatty acids,” Unger said.

According to data presented by Andreen, studies have shown that organic and conventional herds are at similar CLA levels during the non-grazing season. But CLA levels in organic milk increase 55% in the summer, while CLA levels in conventional herds increase 12% during the same time frame, indicating that pasture intake enhances CLA levels significantly.

Consumers are paying a premium for organic or grass-only milk, often marketed with nutritional claims, and they are getting a product differentiated from conventional milk. As consumers increasingly focus on positive health-related food claims, dairy producers have the opportunity to capture value by changing the cow diet. Grazing – with the consumer in mind – is a potential value-added strategy.

View the webinars: Milk Fatty Acids in Organic and Grassfed Dairy Production and Dairy Fat – What's In It For The Consumer?