Grass-Fed Dairy is the Best Source of a Newly Discovered Essential Fat

Are you missing out on an essential nutrient? Odds are, yes - thanks to the modern food system and outdated nutrition dogma.

This essential nutrient is found in abundance in foods that have been unfairly demonized for decades: cheese and dairy.

While mainstream health media continues to vilify dairy and saturated fat, science is finally catching up to what our ancestors knew all along—raw cheese and dairy are nutrient-dense superfoods that have nourished humans for over 7,000 years [r].

But the war on saturated fat isn’t just a misunderstanding—it’s a business strategy. By keeping dairy on the “bad” list, industries profit from cholesterol-lowering medications and ultra-processed dairy alternatives made with cheap, inflammatory seed oils and gut disrupting additives.

Here’s what they want you to believe: saturated fat is harmful.

Here’s what they don’t want you to know: dairy fat is the richest food source of a newly discovered essential nutrient [r].

Meet C15:0, an odd-chain saturated fatty acid that’s being called the first essential fatty acid discovered in 90 years. 

And now, scientists now believe it may be safer and more effective than fish oil and omega-3s [r].

Why C15:0 is Better Than Omega 3s

A head-to-head study compared C15:0 (found in dairy fat) to EPA (a common omega-3 from fish oil) across 12 human cell systems, and the results were striking [r]:

• C15:0 outperformed EPA when it came to lowering inflammation, improving metabolism, boosting mood, supporting immunity, demonstrating anti-cancer effects, and offering greater antimicrobial properties.
• C15:0 was non-toxic at every dose tested, while EPA was toxic at to cells in 4 out of the 12 cell types tested. Why the difference? Omega-3s are polyunsaturated fats (PUFAs), which contain unstable double bonds that are prone to oxidation, meaning they can cause cellular damage when consumed in excess. 

C15:0, on the other hand, is a saturated fat that is more stable, more protective, and less prone to oxidation - leading to greater health benefits.

What is C15:0?

C15:0 (pentadecanoic acid) is an odd-chain saturated fatty acid that is now identified as an essential nutrient you need to get from food [r,r] since your body can’t make in significant amounts on its own. 

Its discovery came from a surprising place: dolphin research. Dr. Stephanie Venn-Watson and her team analyzed decades of data from aging dolphins and found that the healthiest ones had higher levels of this fatty acid. Their research revealed C15:0 as a new essential fatty acid, the first found in over 90 years.

Since then, additional research has backed its vast health benefits [r,r]:

• Strengthens cellular membranes
• Improves metabolic health, repairs mitochondrial function and enhances energy production
• Lowers inflammation 
• Reduces chronic disease risk
• Boosts liver enzyme production and liver function
• Supports a more diverse, resilient gut microbiome
• Associated with lower risks of type 2 diabetes, cardiovascular disease, and even early mortality

“Large, prospective human cohort studies have shown that higher C15:0 blood concentrations are associated with lower risks of developing chronic conditions over time, including type 2 diabetes, cardiovascular disease, and heart failure... Higher dietary intake and circulating concentrations of C15:0 have also been linked to lower mortality and greater longevity, as well as to lower risks of chronic inflammation, gestational diabetes, hypertension, nonalcoholic fatty liver disease, as well as less severe nonalcoholic steatohepatitis and chronic obstructive pulmonary disease.” [r]

Where to Find It? The Foods They Told You to Avoid

Ironically, the richest sources of this essential fat are the ones mainstream health advice has told us to avoid: full-fat dairy and ruminant fats.

That’s right: cheese, butter, milk, beef fat, and lamb fat are all sources of C15:0. (Dairy contains higher levels than beef and lamb fat, but those still contain significant amount when 100% grass-fed!)

But not just any cheese or dairy will do. 

The most concentrated sources are found in grass-fed dairy, especially raw cheese, where the milk fat is naturally preserved and further concentrated due to the cheese-making process.

Cheese is often criticized for its saturated fat content, but that fat is precisely what makes it metabolically supportive. In fact, cheese typically contains about 64% saturated fat (some of which is C15:0!), 28% monounsaturated fat, and only 2.5% PUFA [r]. That’s a pretty ideal fatty acid profile, that 'plant-based' dairy alternatives don't even come close to.

Unfortunately, many people today are unknowingly deficient in C15:0, largely due to the sharp decline in consumption of traditional animal fats and dairy, foods that were wrongly vilified during the decades-long war on saturated fat and cholesterol.

Unfortunately, many people are deficient in C15:0 due to the widespread reduction in consumption of traditional sources like full-fat dairy and ruminant animal fat—foods that have been wrongly vilified in recent decades due to the fear mongering of saturated fat and dietary cholesterol.

The recent surge in plant-based dairy alternatives (completely devoid of C15:0 and high in PUFAs) has only made the problem worse.

Why Grass-Fed Matters

Modern agricultural practices have drastically reduced the amount of C15:0 in our food. As we moved away from traditional pasture-based systems toward confinement animal feeding operations (CAFOs), livestock were removed from rotational grazing and no longer fed diverse, natural pasture-based diets.

As a result, dairy from grain-fed, feedlot cows contains far less C15:0 than dairy from grass-fed cows. 

In fact, cheese and dairy products from grass-fed cows consistently contain significantly higher levels of this essential fat [r].

Here's why:

The fatty acids in milk come from two main sources: the cow’s diet and the microbial activity in the rumen.

Grass-fed cows consume a natural, diverse diet of forage - grasses, legumes, and pasture plants. In contrast, feedlot cows are typically fed grain-based rations, often mixed with industrial byproducts like soybean meal, corn silage, and canola meal.

C15:0 is produced by specific rumen bacteria during fermentation. These beneficial microbes thrive on high-forage diets, leading to greater endogenous production of odd-chain fats like C15:0, which are then transferred to the milk. 

Grain-heavy diets, on the other hand, can suppress these microbes and shift the rumen toward less favorable fermentation byproducts.

As a result, feedlot dairy often contains higher levels of polyunsaturated fats (PUFAs), particularly omega-6s, which are more prone to oxidation, can be pro-inflammatory, and may reduce C15:0 content.

It’s also worth noting that many large-scale “organic” dairies still operate as feedlots and may rely heavily on grain-based feed. That’s why it’s essential to know where your dairy comes from.

Truly grass-fed butter, cheese, and milk aren’t just richer in flavor, they offer more of the metabolically supportive fats your body needs, like C15:0.

How Much Do You Need?

Research suggests most people need 100–200 mg of C15:0 per day to achieve healthy blood levels [r]. 

This is totally achievable if you’re eating grass-fed dairy and meat regularly.

How to Boost Your Intake (Without Popping a Pill)

Here’s how to get more C15:0, naturally:

• ✅ Swap margarine for grass-fed butter
• ✅ Source dairy products from grass-fed and pasture-raised animals (cows, sheep and goats), now livestock in feedlots fed high grain diets
• ✅ Make raw, grass-fed cheese a daily staple

Yes, C15:0 supplements now exist, but why settle for an expensive isolated nutrient in a capsule that could cause gut disruption, when you can enjoy the full nutrient matrix of real food (with better flavor, too)?

Ready for your C15:0 boost?

Now, I am not saying to not eat fish which contains Omega 3s. They have their place in ancestrally appropriate amounts!


I am saying, eat ya cheese!

The modern food has stripped away so many of the nourishing fats our ancestors thrived on. 

Reintroducing raw, grass-fed cheese is more than just tasty, it’s one of the most enjoyable, effective ways to support your metabolic health, reduce inflammation, and supply your body with a newly recognized essential fat.

Ready to get your C15:0 boost?

Try some of our Raw, A2, 100% Grass-fed Cheese - delivered conveniently to your door, packed with flavor and metabolic benefits.

➡️ Shop C15:0 rich Raw Cheese