Milk fat can be good for you. Surprise!
The fat in milk has long been demonized due to being high in saturated fat.
In the U.S., during the 20-year period following the initial recommendation to limit saturated fat, the average individual’s daily intake of whole fat milk was reduced more than 4-fold. However, despite this drop in whole fat milk intake, the global prevalence of obesity, type 2 diabetes, metabolic syndrome, and nonalcoholic fatty liver disease has increased (R).
More and more research shows that milk, and especially milk fat, has many benefits. Many of the studies in this article look at the difference between skim, low fat and whole milk and many studies found that whole milk is inversely correlated with health conditions and the benefits diminish as the fat content in milk or dairy products is reduced.
I’m not trying to justify only milk fat here; milk as a whole is a great food that contains a good amount of protein, carbs and valuable micros such as B-vitamins, fat-soluble vitamins, calcium, etc.
Weston A. Price found that it’s the milk fat during the spring period that is the richest in vitamin D and K2 which had tremendous benefits for bone development as well as having cavity curing properties.
But apart from the micro-nutrients in the milk, the saturated fat itself also has numerous benefits. First I want to show you the benefits of milk fat and then I’m going to dive more deeply into individual saturated fatty acids.
Benefits of milk fat
Dairy fat against metabolic syndrome
Metabolic syndrome is a cluster of conditions which include high blood pressure, high blood sugar, excess body fat around the waist and abnormal cholesterol levels. Which is basically the increased risk of heart disease, stroke and diabetes.
This study found that milk fat is inversely correlated with metabolic syndrome:
After adjusting the confounding variables, the highest to the lowest quintile of butter and Kermanshah ghee consumption showed a reverse correlation with the MetS (OR = 0.7, 95% CI = 0.5–0.9) and (OR= 0.7, 95% CI=0.6–0.9), respectively.Reference
This study didn’t specifically look at the difference between whole, low fat or skim milk, but nonetheless found this:
Men and women who consumed >4 servings of dairy products per day had lower levels of systolic and diastolic blood pressure, 2-h postload glucose, and TGs (triglycerides).Reference
And here is where it gets interesting with saturated fat specifically:
Finally, we did not observe significant association between total dietary fat content and T2D (P-trend = 0.24), but intakes of saturated fatty acids with 4-10 carbons, lauric acid (12:0), and myristic acid (14:0) were associated with decreased risk (P-trend < 0.01).Reference
Although according to this study these specific fats weren’t directly beneficial, it didn’t have detrimental effects as portrayed everywhere:
palmitic acid (16:0) and stearic acid (18:0), which are abundant in both dairy foods and meat, fish, and eggs, showed null associations with T2D.Reference
More goodness on saturated fat from dairy and insulin resistance:
There is no evidence that dietary saturated fatty acids from varied food sources affect the risk of insulin resistance or T2DM, nor is intake of full-fat dairy products associated with this risk.Reference
Forsythe et al.10 found that low-carbohydrate diets high in saturated (86 g of saturated fat per day) or unsaturated (47 g of saturated fat per day) fats have equal impact on the concentration of circulating saturated fatty acids and the serum insulin concentration in weight-stable men, thus raising questions about the effect of a high intake of saturated fat on insulin resistance and risk of T2DM.Reference
And some more…
In our previous analysis of this same population, ELSA-Brasil, we found inverse associations between dairy consumption and levels of glycemia and insulinemia that were independent of obesity. This association was possibly mediated by myristic acid (9).Reference
From this study:
6 intervention studies showed that, in overweight individuals with26–28 or without30–32 features of metabolic syndrome, decreasing saturated fat to approximately 10% in comparison with approximately 15% of energy intake does not improve glucose-insulin homeostasis, as assessed by an oral glucose tolerance test. Thus, most of the prospective and intervention studies demonstrate that dietary saturated fat at levels ranging from 13% to more than 20% of energy intake is not associated with an increased risk of T2DM.Reference
Ever heard that trans fat is bad for you? Yet, even the trans fat in milk is beneficial (more on this fatty acid later as well):
This is further supported by the results from the prospective Multi-Ethic Study of Atherosclerosis,12 which showed that trans-palmitoleate plasma concentrations, which are positively correlated with consumption of full-fat dairy products, were independently associated with a lower incidence of T2DM, including a 48% lower risk in quintile 5 compared with quintile 1.Reference
And even more…(milk fat doesn’t appear to make children fat)
Further, an 18-year longitudinal study including over 25,000 individuals demonstrated that children fed whole fat milk had a lower risk of having obesity compared to children who were provided fat-free or 1% fat milk, and multiple studies have demonstrated associations between higher dietary intake of full-fat dairy and reduced risk of type 2 diabetes and cardiovascular disease.
Three more on dairy fat and weight gain:
Studies were consistent in reporting that whole-fat dairy products were not associated with increased measures of weight gain or adiposity.Reference
This meta-analysis found that observational research suggests that higher cow-milk fat intake is associated with lower childhood adiposity. International guidelines that recommend reduced-fat milk for children might not lower the risk of childhood obesity.Reference
In general, clinical trials suggest that an increased consumption of dairy-derived SFA resulted either in neutral [47,48,49,50,51,56,57] or favorable [46,58] changes in body weight and body composition.Reference
More on insulin sensitivity…
Wanders et al.  demonstrated that the consumption of SFA from dairy products was inversely associated with fasting insulin concentrations and homeostatic model assessment of β-cell function (HOMA-B) in overweight adults.Reference
One very interesting fatty acid in dairy fat, pentadecanoic acid, an odd chain fatty acid, has some very interesting and beneficial properties (more on that later):
A study with a multiethnic population of adult men and women free of type 2 diabetes from the U.S. observed that serum concentrations of 15:0 were positively associated with log SI (insulin sensitivity index) and log DI (disposition index), both proxies for insulin sensitivity and β-cell function, respectively.Reference
Dairy fat and cardiovascular disease:
Each 5-unit increment in the percentage of energy from dairy fat was associated with a 38% lower risk of CVDReference
And last but not least, dairy fat and heart disease:
Total SFA intake was associated with a lower ischemic heart disease risk… Slightly lower IHD risks were observed for higher intakes of the sum of butyric (4:0) through capric (10:0) acid (HRSD: 0.93; 95% CI: 0.89, 0.99), myristic acid (14:0) (HRSD: 0.90; 95% CI: 0.83, 0.97), the sum of pentadecylic (15:0) and margaric (17:0) acid.Reference
I know a lot of the studies are observational (not all), which doesn’t have a lot of strength, however, there are a lot of observational studies that are finding the same benefits, which definitely shows that there is something to it.
There are many more studies on dairy and various other health benefits, but I want this article to focus specifically on dairy fat and saturated fat.
Dairy fat broken down and simplified
Dairy fat is composed of more than 400 different identified fatty acids (FAs) and FA derivatives, but only about 15 FAs represent quantities greater than 1% of total FAs. Milk fat is high in saturated fat, including short-, medium-, long-, odd-, and branched-chain FAs.
Saturated fatty acids are the most abundant class of fat in dairy fat, accounting for a range between 57–73% of total FAs.
If you log whole milk into cronometer, the fat consists of about 57% saturated fat, 6% polyunsaturated fat, 25% monounsaturated fat and 3.5% transfat.
Because milk fat is so rich in saturated fat, it’s often demonized…because “saturated fat is bad” you know.
For that reason we’re going to focus specifically on saturated fat.
As most of us already know, saturated fat is a group of fats which contain no double bonds. They range from propionic acid (C3) all the way to tetracontylic acid (C40). The long chain saturated fats, ranging from C12 to C18 are the most commonly found in food, with longer or shorter chain fatty acids becoming much rarer.
Saying that all saturated fat is the same is like saying testosterone and DHT are the same because they’re both androgens.Tweet
Changing a saturated fat just by one carbon, e.g. C14 (myristic acid) to C15 (pentadecanoic acid), completely changes its function and “abilities”, although they still have some overlapping properties.
Unlike other animal-derived fats, milk fat’s SFAs uniquely consist of SFA with varying carbon chain length ranging from C4 to C24.
Short chain saturated fats
The content of short-chain SFA (4:0–6:0) in milk fat is about 5-11% of total FA.
The short chain fats include butyric-, valeric- and caproic acid.
Medium chain saturated fats
The content of medium-chain SFA (7:0–13:0) in milk fat is about 8% of total FA.
These fats include enanthic-, caprylic-, pelargonic-, capric-, undecylic-, lauric- and tridecylic acid.
Long chain saturated fats
The majority of SFA in milk, about 58%, are long-chain FA (C14 to C21), with palmitic acid (C16) being the prominent SFA followed by stearic acid (C18) and myristic acid (C14).
Milk fat also contains a minor amount (3% of total FAs) of bacterial-derived odd-chain FA (OCFA), primarily comprised of pentadecanoic acid (15:0) and heptadecanoic acid (17:0), each about 1% of total FAs.
Let’s discuss some individual saturated fatty acids
Since it’s nearly impossible to discuss saturated fat as one category, we can discuss each fatty acid on their own as each has its own functions and effects in the body.
As a side note, fatty acids can be broken down through beta-oxidation into shorter fatty acids or elongated into longer fatty acids, which will also affect their functions. For example, consuming myristic rich fat (e.g. nutmeg butter) can increase palmitic acid in the body because the myristic acid is elongated to palmitic acid. Palmitic acid can also further be elongated to stearic acid, which changes its functions again.
Furthermore, these fatty acids can be unsaturated, which again changes their function. For example, palmitic acid signals the body to become insulin resistant. However, the palmitic acid can be desaturated into palmitoleic acid (C16:1n-7; an omega 7). Palmitoleic acid in turn signals insulin sensitivity on a high carb diet, which allows more carbs to be taken up into tissue.
All of this is normal.
So lets dive into the individual fatty aids.
Butyrate and other short chain fatty acids
Butyrate occurs in dairy products in considerable amounts, e.g. whole cow’s milk
(~0.1g/100g), cream (~4.4g/100), butter (~3g/100g), cheese (especially goat’s cheese (~1-1.8g/100g) and parmesan (~1.5g/100g).
Consuming three servings of whole milk translates into ~700 mg butyric acid/day. Butyric acid is one of the most potent inhibitors of histone deacetylase (HDAC) and an agonist of specific G protein-coupled receptors.
Butyrate can (R):
- Improve insulin sensitivity by reducing leaky gut, lowering gut inflammation and modifying the gut bacterial community structure.
- Increase total energy expenditure.
- Protect against atherosclerosis.
- Increases uncoupling protein UCP-1 expression in brown adipose tissue, suggesting that butyrate may enhance thermogenesis.
- Promote satiety by inducing intestinal hormone secretions of GLP-1, GIP, and PYY.
- Activate AMPK in skeletal muscle, which promotes autophagy and mitochondrial biogenesis.
- Downregulate lipogenic pathways (de novo lipogenesis which is the process of converting carbs to fat) in the liver and adipose tissue.
- Improve β-cell function.
- Reduce inflammation.
- Modify short-chain FA receptor expression.
- Modify the immune system to a more anti-inflammatory type.
- Promote calmer mood, by increasing GABA (R, R).
- Potentially inhibit cancer initiation and growth, by inhibiting HDAC.
Butyrate has been extensively studied so far, and relatively limited work has investigated valeric (5:0) and caproic (6:0) acids. Recently, it has been found that dietary valerate has anti-inflammatory properties and, like butyric acid, has histone deacetylase inhibitor activity.
Furthermore, dietary caproate has been shown that it may beneficially modulate lipid metabolism in studies performed in chicken liver cells (R).
Medium chain fats found in dairy fat
I don’t want to say too much about the MCTs here because I’ve already written about them here, but just a few quick facts about caprylic acid (C8).
Caprylic acid (R):
- Is unique because it is the only FA known to be involved in the acylation of ghrelin, which modifies the action of ghrelin to be able to stimulate growth hormone release.
- Downregulates the expression of enzymes that uptake fat or synthesize fat in the fat stores.
- Reduces the secretion of apolipoprotein B, a component of low-density cholesterol particles (In chicken liver cells at least).
- Reduces VLDL-cholesterol synthesis.
- Inhibits FA synthase activity, a key enzyme in de novo lipogenesis (DNL).
- Enhances glucose-stimulated insulin secretion in a dose-dependent manner.
Lauric acid is the most abundant saturated fat in coconut oil, but is also found in decent amounts in dairy fat.
Consuming three servings of whole milk translates into ~800 mg lauric acid/day.
Evidence show that lauric acid can help reduce postprandial glucose levels through GLP-1 stimulation in humans, which helps to lower high blood sugar (R).
In spontaneously hypertensive rats, lauric acid, administered intravenously, lowered heart rate and blood pressure (R).
Lauric acid can also help against atherosclerosis by lowering key enzymes involved in its development, namely A disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) −1, −4, and −5 (R).
Thus, the limited body of evidence suggests that lauric acid may exert anti-hypertensive and anti-atherosclerotic properties.
Residents of southeast Asia with constant use of coconut oil, have a low level of diseases of the cardiovascular system in the population (R). Coconut oil has a positive effect on the cardiovascular system, by preventing the formation of atherosclerosis and atheromatosis.
Additionally, lauric acid:
- Is burned very rapidly because of its shorter chain length. , so less fattening, less prone to causing oxidative stress and inflammation (cannot be oxidized similar to PUFAs).
- Has anti-fungal properties against candida and is potent anti-bacterial. It has low antimicrobial activity against commensal lactic acid bacteria, but high antimicrobial activity against pathogenic Bacteroides and Clostridium, suggesting that LA might modulate intestinal health, as confirmed by the proposed method (R).
- Could be effective against cancer (R, R).
- Has strong anti-endotoxin properties (R). Endotoxins are released from gram-negative bacteria in the gut and are known to promote inflammation and autoimmune conditions.
Myristic acid is found in relatively modest amounts in milk fat, with an average of 12% (12g/100g) (R).
This study found that fermented dairy products showed particularly strong inverse associations with the markers of insulin resistance. Now, most people will think: “Ah, it’s the probiotics”, however, the study concluded that myristic acid was the only nutrient that appeared to mediate the association between dairy intake and glycemia (R).
Myristic acid stands in the shade of the other fatty acids, such as lauric acid, palmitic acid and so on, but there is some promising research showing its benefits.
- Has been found to have the highest binding potency with the human G protein-coupled receptor 40 (GPR40), a major LCFA receptor expressed in enteroendocrine and β-cells.
- “Recent work in mice showed that dietary supplementation with myristic acid enhances glucose tolerance and insulin sensitivity . Further investigation in C2C12 murine myotubes demonstrated that these beneficial effects may be mediated by promoting glucose uptake via stabilization and therefore increased expression of diacylglycerol kinase in skeletal muscle [105,106].” (R)
- Is able to enhance the incorporation of the omega 3, DHA, into tissues, such as cholesteryl esters (R).
- Binds to specific amino acids on proteins, thus altering their functions. This is called myristoylation. Myristoylation, because it’s so similar to palmitoylation, can easily be thought of as undesirable. However, this modification is reversible and beneficial. For example, myristoylation is the major, but not the only, determinant of the anchoring of eNOS in the membrane. This anchoring allows better extracellular release and a more effective vasodilator action of nitric oxide.
Palmitic acid (C16) is becoming one of the most hated-on saturated fatty acids out there. But I think it’s just being misunderstood.
About 30% of the saturated fat in cows milk consists of palmitic acid.
Palmitic acid is thought to promote insulin resistance, fatty liver, liver dysfunction, inflammation everywhere in the body, negatively modulate protein and enzyme activity, contribute to cancer, promote cardiovascular disease, etc., which of course is not as simple as that.
Let’s discuss palmitic acid and insulin resistance. Circulating palmitic acid in the blood is not an indication of dietary intake, because the total amount of palmitic acid in the blood comes from dietary intake, de novo lipogenesis and lipolysis; the latter two being elevated during insulin resistance. When nutrients are abundant, circulating palmitic acid increases to signal the tissue to become more insulin resistant to prevent an overload of nutrient uptake into tissue. Makes sense right?
Slight detour on palmitoleic acid
Palmitoleic acid (C16:1n-7), which is the desaturated form of palmitic acid, signals the tissue to be more insulin sensitive (R, R). Circulating palmitoleate is proportional to fat mass, so as long as someone is able to produce palmitoleic acid, they can remain insulin sensitive and gain more fat mass. However, somewhere along the line, fat cells become too extended and inflamed, which then results in insulin resistance. There are huge individual and racial differences between how much fat someone can gain before they become insulin resistant. Consuming too much omega 6 definitely speeds up the process.
Interesting, dairy fat is a relatively good source of trans-palmitoleate that also has this insulin-sensitizing effect. Both the cis isomer from endogenous fat synthesis and the trans isomer from whole-fat dairy intake has been associated with lower metabolic risk (R).
More on this fatty acid in a future article.
Back to palmitic acid
Let’s discuss palmitoylation. The protein modification of palmitic acid has been thought to be detrimental and this is a big reason to avoid palmitic acid.
However, palmitoylation is reversible. Compared to the other lipid modifications, palmitoylation is readily reversible due to the lability of the thioester bond.
Palmitoylation is the attachment of palmitic acid to the cysteine residues of proteins via a thioester linkage. This process is actually called S-acylation. Other fatty acids that are present in S-acylated proteins include myristic acid (C14), palmitoleic acid (C16:1n-7), stearic acid (C18:0), and oleic acid (C18:1n-9).
This reversible post-translational modification influences protein stability, function and is often indispensable in the trafficking of a protein to the membrane or to specific membrane domains.
One such example is the palmitoylation of neuronal proteins, including synaptic scaffolding proteins, G-protein-coupled receptors (GPCRs) and synaptic vesicle proteins. Palmitoylation of these proteins is vital for regulating proper neuronal development and function, including neuronal differentiation, neurotransmission, and neurotransmitter release (R).
It’s the defects in S-palmitoylation of some proteins thathave been linked to the specific disorders.
Other than palmitoylation, palmitic acid enhances energy production through oxidative phosphorylation (R), decreases excess fat transport into the cell and oxidation (R, R), is possible even anti-inflammatory (R) and have pro-androgenic effects (R, R).
Stearic acid is one of my favorite fatty acids, since it has such unique beneficial effects.
Stearic acid is about 12% total saturated fat in milk fat (R).
- Promotes mitochondrial fusion which enhances cellular function and energy production. Diabetes and other energy defective conditions are known to have small fragmented mitochondria. Such mitochondria create an excess of reactive oxygen species, low energy and low androgens.
- Has a neutral effect on cholesterol in humans and is thoroughly reviewed in this study (R).
- Increases the potent anti-inflammatory cytokine IL-10 (R).
- Has anti-fibrotic effects (R).
- Protects against lipid peroxidation, an indicator of oxidative stress, via activation of peroxisome proliferator-activated receptor γ (PPARγ) (R).
- Has a beneficial effect on whole-body energy metabolism (R).
- Displaces linoleic from cell membranes and can help enhance cellular function, reduce cellular instability and lower inflammation.
Odd chain fatty acids (OCFAs)
Now we’re getting to the interesting fatty acids.
Odd chain fatty acids are the ones with a uneven carbon number, e.g. C3, C5, C15, C17, etc.
Propionic acid (C3) is produced by bacteria in the gut, but is also found in small amounts in dairy fat. This fat can be elongated to C15 and C17. However, C15 (pentadecanoic acid) is also found in small amounts (1%) in dairy.
More research are coming out looking at pentadecanoic acid, which is fascinating.
Higher dietary intake and circulating levels of OCFAs have been associated with lower risks of adiposity, chronic inflammation, cardiovascular disease, metabolic syndrome, type 2 diabetes, nonalcoholic steatohepatitis (NASH), chronic obstructive pulmonary disease, pancreatic cancer and other conditions.
- Enhances membrane fluidity, which improves insulin sensitivity (R).
- Has anti-tumor properties (R, R).
- Attenuates inflammation, anemia, dyslipidemia, and fibrosis in vivo (R), potentially by binding to key metabolic regulators and repairing mitochondrial function.
- Is a dual, partial PPARα and PPARδ agonist, similar to C14 and C16, suggesting that carbon chain length may be a determinant of PPARα/δ binding (R).
- As well as C16, C17 and C18:0 supplementation lowered mitochondrial reactive oxygen species production compared to the non-supplemented control group (R).
- Has dose-dependent anti-inflammatory activities, including reducing monocyte chemoattractant protein 1 (MCP-1), secreted immunoglobulin G (IgG), proinflammatory chemokines (CXCL9, 10 and 11), cytokines (IL-6, -17A), and adipokines (platelet activation inhibitor 1, or PAI-1). This anti-inflammatory effect of C15 may contribute to their associations with lower adipokines and lower risks of type 2 diabetes, cardiovascular disease, pancreatic cancer, and mortality (R).
- Had antifibrotic activities, including reduced Collagen I, plasminogen activation inhibitor 1 (PAI-1), and 72-hour fibroblast proliferation (R). Its potent anti-fibrotic properties could thus work great against aging, liver fibrosis, scalp fibrosis (if applied topically), scarring, loss of muscle and cellular function, etc. The dose they used in this animal study equated to 200mg daily. Milk fat has about 1% C15 so you’ll have to eat 200g for 200mg, which is a lot.
- Is able to lower cholesterol, triglycerides, globulins, and platelets compared to non-supplemented diseased controls (R).
- “Similarly, a case-cohort study involving 15,919 humans across eight European countries demonstrated associations between higher plasma phospholipid C15:0 and C17:0 concentrations and lower total cholesterol and triglycerides” (R).
- Improves liver health, which includes markers such as bilirubin and jaundice (R).
- Can be elongated to very-long-chain FAs (VLCFAs) such as tricosanoic acid (23:0) and pentacosanoic acid (25:0) in glycosphingolipids, particularly found in brain tissue.
- Can be shortened, yielding propionyl-coenzyme A (CoA). Propionyl-CoA, by succinyl-CoA, can replenish the citric acid cycle (CAC) with anaplerotic intermediates and, thus, improve mitochondrial energy metabolism.
This study even goes as far as saying that C15 should be classified as an essential fatty acid, due to meeting the requirements of being one.
Pairing our findings with evidence that (1) C15:0 is not readily made endogenously, (2) lower C15:0 dietary intake and blood concentrations are associated with higher mortality and a poorer physiological state, and (3) C15:0 has demonstrated activities and efficacy that parallel associated health benefits in humans, we propose C15:0 as a potential essential fatty acid.Reference
That is it for this article. I did not write this article to endorse the consumption of kilograms of cows fat on a weekly basis, but just to make you aware that dairy fat, and specifically saturated fat, are unnecessary demonized.
There are more and more evidence emerging that dairy fat is inversely correlated with many forms of health abnormalities and that saturated fat is actually not as bad as it’s been made out to be.
However, if you don’t react good to whole milk, try low fat or skim. If you can get your hands on non-homogenized milk or even raw milk, then that would be an even better experiment to do to see how you react to those forms of milk.
There are many ways you can experiment with dairy, for example, whole, low fat or skim milk, yogurt, whey, different forms of cheese, raw vs pasteurized vs UHT pasteurization, homogenized vs non-homogenized, lactose-free, etc.
Keep in mind that when it comes to fat loss or maintaining your weight, it still comes down to how many calories you expend and how many you consume. If you consume more than you expend, chances are you’ll gain weight. Upping fat intake is the easiest way to get fat since they are so rich in calories. Plus, they make food taste delicious, so people tend to eat a lot of it.
If you don’t want to gain weight, keep an eye on your weight, and if it’s going up, you might be consuming too many calories.
If you are pleasantly surprised by the facts of this article, you’d definitely benefit from learning more truths that have been withheld from you, as well as simple and effective dietary strategies to implement.
As always, thanks so much for reading my article. Let me know in the comments below if you have any questions. And if you found this article to be insightful and helpful please like and share so this information can help others as well.
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