Casein: is the newly crowned king about to get dethroned?

Why dairy and casein might actually be more harmful than gluten

Written by: Joachim Bartoll, March 2016
Classic Muscle Newsletter, April 2016 (issue #19)


Cottage Cheese - the fitness enthusiast's kryptonite?Over the last couple of years or so, casein has had some kind of reincarnation in the fitness industry. Several articles and websites have claimed casein to be a better choice than whey.
However, if we strictly look at the protein and its properties, it all comes down to what you nutritionally want to achieve – as casein and whey are very different.

For the sake of simplicity, let’s skip immunoglobulins (in whey), amino acid content, and protein fractions. The main difference lies in absorption rates. Casein will form a gel-like substance in your gut, slowing down gastric emptying and the uptake of amino acids within the small intestine. This makes casein very anti catabolic as there will be a steady supply of amino acids. It also means that you cannot achieve hyperaminoacidemia and promote protein synthesis while casein is being digested. The only way to promote protein synthesis and anabolism through ingestion of protein/amino acids is by quickly raising the concentration of amino acids in the bloodstream. This will happen with both casein and whey as long as you get at least 3 grams of leucine, but it will happen a lot faster when consuming whey.
Now, to be able to promote protein synthesis again, the levels of amino acids in your bloodstream must first return to baseline (normal, as in a fasted state). If you ingest more protein while your amino acid levels are still elevated, nothing will happen. There will not be any new peak in protein synthesis or anabolism. Nothing.

That’s the problem with casein and all slow releasing protein sources. They might be a good idea at night to help with recovery through a long and slow release of amino acids (unless you’re into intermittent fasting, as that would delay your fasting window) or before several hours of exercise as a protection against catabolism (but I would rather sip on some BCAAs or EAAs, since I would need fluids anyway).
This is why I have always preferred whey protein. It’s fast acting. Whey protein will peak your blood amino acid concentration within 30 to 60 minutes, and after 2,5 to 3 hours you’re back to baseline again – which means that if you really wanted to, you could use a protein/amino acid pulsing protocol and maximize protein synthesis and anabolism every 3 hours. It can also be used before a workout and you can still achieve hyperaminoacidemia when you eat your post-workout meal an hour after your training session.
As you can see, the use for casein is in reality quite limited – unless you use it while being on a low calorie diet. And although some people swear by it and says it’s the perfect pre-workout protein (it’s not), there might be other – a lot more serious reasons, to avoid casein.

A1 casein and the Holstein and Friesian connection

Casein from Holstein Friesian cows are bad, m'kay?

Holstein Friesian cows on pasture.

A lot of us avoid dairy because of lactose intolerance. And even if you can handle lactose pretty well, it’s still a stressor – problems could accumulate down the road. The good thing about casein related products are that they’re low in lactose – more so than whey protein products with similar protein content.
Now, there are a lot of lactose free products on the market. I’ve tried a lot of them, but I still get a lot of symptoms associated with inflammation and intolerance/allergy reactions – such as, runny nose, phlegmy throat, harder to inhale and/or exhale (asthma related), swollen/puffy face in the morning, brain fog, loose stools, tiredness, and so on.
A lot of my clients have reported the same discoveries. Also, several research papers on lactose intolerance states the following, “many who self-report lactose intolerance show no evidence of lactose malabsorption. Thus, the cause of their gastrointestinal symptoms is unlikely to be related to lactose”. So, what is it in dairy that make so many of us ill – if it’s not lactose?

Since I’ve never been a fan of casein and its properties, I never really used casein supplements or dairy products containing a lot of casein protein. Not in my own diet and not with my clients. Then, last year, I stumbled across some studies on autoimmune diseases and they mentioned A1 casein and casomorphin as highly inflammatory.
Since then, I’ve tried to add high quality casein protein powder products to my diet in various amounts. And sure enough, since it’s concentrated casein, it didn’t take much before the symptoms associated with dairy flared up. I also tried the same approach with some volunteering clients who all claimed to have problems with dairy. All of them felt worse when adding casein protein to their diet.

So what is this A1 casein? Casein is the main protein in cow milk, making up 80 % of the total protein content (the other 20 % is whey protein). Casein contain four different fractions called alphas1, alphas2, beta, and kappa-casein. Among these fractions, beta-casein actually comes in two different (genetic) variants: A1 beta-casein and A2 beta-casein. These two are nearly identical in structure except for the amino acid at position 67. A1 contains histidine while A2 contains proline.
A2 beta-casein is recognized as the original beta-casein because it existed before a mutation caused the appearance of A1 beta-casein in European herds a few thousand years ago.

Today, A1 casein mainly comes from milk produced by the world's highest-production dairy animals, the Holstein and Friesian cows, who are the dominant breeds in western and northern Europe, North and South America, and Australia. Actually, the Holstein and Friesian cows represent about 90 percent of the dairy industry in the world, with an additional 3 % from Holstein and Friesian cross breeds and only 7 % from other breeds.
Dairy cows in Africa, Asia, Iceland and southern Europe make milk with mostly A2 casein. The Guernsey breeds produce only about 10% of their beta casein as A1 while the Jersey breed produces about 35%. The Ayrshire, Holstein, and Frisian breeds tend to produce 50% A1 or more.

Milk that has predominantly or exclusively A2 casein is fine for most people. Goat’s milk is A2, and so are most other species’ milk. Dairy products that are mostly fat (such as butter) are also fine, as they contain little to almost no casein at all. And guess what, human milk only contains A2 casein. Not really surprising, is it?

So, unless you live in areas with local dairy production from A2 cows, the dairy you consume is by all probability containing A1 casein. And as far as casein protein supplements go, it’s very difficult to find any using the rare A2 casein.

A1 casein and casomorphin – bad news for many of us

The bond between histidine and its linked amino acids in A1 is much weaker and much more easily broken than the bonding of proline in A2. This splitting between the bonds happens during the digestive process and it creates a peptide called beta-casomorphin-7 (BCM7 or simply “casomorphin”), which activates μ-opioid receptors expressed throughout the gastrointestinal tract and the entire body. In humans, a double-blind, randomized cross-over study showed that participants consuming milk containing A1 casein experienced statistically significantly looser stool compared with those receiving A2 casein milk. Additionally, a statistically significant positive association between abdominal pain, poor nutrient uptake, and stool consistency was observed when participants consumed the A1 but not the A2 casein products. This is due the massive release of histamines from casomorphin.

In other words, many of us can’t neutralize the casomorphin that are released during digestion of A1 casein. This leads to both an inflammatory and immune response within the gastrointestinal system.
While the immediate effect can be noticed in form of looser stools, mild cold-like symptoms or in extreme cases by abdominal pain or allergic reactions, the long term effects are much, much worse.

Although the differences between A1 and A2 was discovered in the 90’s by researchers in New Zeeland, the research on A1 and A2 casein and the opioid peptide casomorphin has only been going on for a few years. The potential biological activity of the opioid peptide casomorphin was first noticed in a report from the European Food Safety Authority (EFSA) in 2009 after some studies reported the possibility of disease and infant death syndrome from milk-based infant formulas. In 2012 the research escalated and we now know that A1 casein is a trigger for Type 1 diabetes (the research around this is fascinating). It is also highly implicated in coronary artery disease and autoimmune disease (this is where I first learned about casomorphins).
A1 casein is also involved, together with gluten, in Autism and Schizophrenia. In fact, according to some researchers, casomorphin is more damaging to the brain than the gliadorphin from gluten.

Since casomorphin is an opioid peptide, its drug-like effect explains why it worsens anxiety and mood disorders, and causes cravings for dairy and sugar. The inflammation from A1 casein causes lymphatic congestion, metabolic suppression, and can lead to weight gain. Studies on A1 milk products has shown that it can worsen acne, eczema, upper respiratory infections, asthma, and allergies (I have experienced this first hand myself).
And since A1 casein produce inflammation, our brain is affected which leads to decreased cognitive processing speed and accuracy (aka brain fog.)

The fitness craze around cottage cheese – are you consuming your own kryptonite?

For some unknown reason, cottage cheese and quark/curd cheese has become extremely popular in northern Europe. Sure, these products contain a lot of cheap protein and it will keep you pretty full for a few hours when you’re on a diet.

However, in light of all this new research and the fact that many of us can’t neutralize casomorphins, this dairy craze is probably backfiring for a lot of people. And even if you neutralize a lot of the casomorphins, there’s no guarantee that ALL of it is being neutralized. Actually, it’s much more likely that there is a small reaction even in the most tolerant of people – just enough to cause problems in the long run. And the risk will be greater if your gut integrity is already compromised from other allergens, medicines or simply a poor diet. If the lining of your digestive tract is damaged, casomorphins will without a doubt make it thought the intestine wall, which will cause an even greater immune response.

So what to do? Most people will be just fine with a sensible consumption of casein protein, but if you have been experiencing any of the previously mentioned symptoms, it might be a good idea to take some action.
First, it all comes down to how much casein protein you actually get from a product. A pure casein protein powder will easily yield 30 grams per serving, which is equivalent of 250 to 300 grams of cottage cheese/curd cheese. It should also be noted that micellar casein (as seen in most protein powders) has much higher levels of peptides such as casomorphins.
A few grams of casein, as in a glass of milk, might be fine even if you’re intolerant, while a shake of casein protein or a cup of cottage cheese might push you over the edge. For me, about 150 grams of cottage cheese/curd cheese or only 20 grams of pure casein protein powder is enough to produce phlegm in my throat, cause brain fog, and lack of energy.

If you are concerned and want to see if cutting out A1 casein will improve your health, your alternative is to switch to products made from goat milk – or simply ditch all high protein dairy and casein products all together (unless you know for certain that you can get dairy from A2 producing cows somewhere in your country). The latter might actually be a really good idea. Throw out all dairy and all casein supplements for 6 to 8 weeks. Then try them again while keeping a diary of how you feel and look. If you can’t find anything different after a week with dairy and casein back in your diet, you’re probably fine. However, if you feel any symptoms, you now know why and what to avoid.

And as mentioned earlier, high fat and/or low protein dairy products is not really a concern, as they contain almost no protein at all. So grass-fed butter still remains as a super food, heavy cream should be just fine (since you hardly gulp it down as you would with milk), as well as natural Greek yoghurt and Kefir in moderate amounts a few times a week.

Expect to see a lot more about A1 casein in the future as scientist and researchers dig deeper. I’ll will follow up on new research and what is happening within the supplement industry in upcoming issues of the Classic Muscle Newsletter. Stay tuned!

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Summary from 2015 with 60 cited studies:

Milk Intolerance, Beta-Casein and Lactose
Sebely Pal, Keith Woodford, Sonja Kukuljan, and Suleen Ho.
Nutrients. 2015 Sep; 7(9): 7285–7297.

More references and further reading:

Bread and Other Edible Agents of Mental Disease.
Paola Bressan and Peter Kramer.
Front Hum Neurosci. 2016; 10: 130.
Effects of milk containing only A2 beta casein versus milk containing both A1 and A2 beta casein proteins on gastrointestinal physiology, symptoms of discomfort, and cognitive behavior of people with self-reported intolerance to traditional cows’ milk.
Sun Jianqin, Xu Leiming, Xia Lu.
Nutr J. 2015; 15: 35. Published online 2016 Apr 2. doi:  10.1186/s12937-016-0147-z.
Food-derived opioid peptides inhibit cysteine uptake with redox and epigenetic consequences.
Malav S Trivedi, Jayni S Shah, Sara Al-Mughairy, Nathaniel W Hodgson, Benjamin Simms, Geert A Trooskens, Wim Van Criekinge, and Richard C Detha.
J Nutr Biochem. Author manuscript; available in PMC 2015 Oct 1.
Formation and Degradation of Beta-casomorphins in Dairy Processing.
Duc Doan Nguyen, Stuart Keith Johnson, Francesco Busetti, and Vicky Ann Solah.
Crit Rev Food Sci Nutr. 2015 Dec 6; 55(14): 1955–1967.
Epigenetic effects of casein-derived opioid peptides in SH-SY5Y human neuroblastoma cells.
Malav S. Trivedi
Nutr Metab (Lond). 2015; 12: 54.