Cows produce one of two forms of beta casein depending on their genetics: A1 or A2. The A1 mutation occurred relatively recently in human history-- all other species of mammal have casein that is more similar to A2 casein. The problem is that A1 casein breaks down into casomorphins in the gut (peptides that act as opiates in the brain) and has been linked to various diseases of civilization. It all seems to be epidemiological at this point.1
Does anyone think this is a serious concern? I used to rely on cheese for a lot of my energy, but I noticed that I seemed to get headaches if I did not have cheese for a day or two. I have since eliminated bovine casein except for the minimal amounts in heavy cream as a precaution.
asked byActon (2041)
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on February 16, 2010
at 03:12 PM
I've personally cut out A1-beta casein, since I've found it makes me mentally sluggish and gives me a brain fogginess. (I too used to live on cheese). I only eat goat/sheep casein now. A2 casein can still cause digestive problems if you're sensitive (since it's hard to digest) but it should avoid the opioid effects. That said I still drink cow's cream with no (noticeable) ill effects.
I think the data is not purely epididemologic since there are demonstrably effects that these pseudo-opiates have in the body, as you say. All the links to CVD, diabetes etc are just associations though, I grant.
One other thing I've wondered is whether people feel any effects from whey? I personally feel ok after some ricotta (whey cheese), but too much whey protein seems to have something of a somnolent effect (but maybe it's just all the insulin). However there seem to be bioactive peptides in whey as well; 1,2
As a practical point though, it seems to be very subjective. If you feel fine on casein, since it's so convenient I'd go with it, as I advise my cheese-reliant friends to do. Plenty of people are obviously sensitive to dairy, (which is clearly suboptimal to meat generally), so I'd mostly leave it to the individual, dairy is clearly one of those evolutionary grey areas which varies a lot.
on February 18, 2011
at 12:10 AM
aside from A1 - A2 problem, there is a problem of, as far as i've read, 'timing' - modern dairy farming techniques (hormones, feeds, etc.) allow rather unnatural situation of a cow being milked during pregnancy (wheres in traditional farming - only after) - and expecting a calf is a rather peculiar state for a cow in terms of hormonal balance which in its turn affects the resulting product (milk) in a peculiar way - and finally we have rather peculiar effects from consuming peculiar milk from cows in a peculiar state
on February 17, 2011
at 01:18 PM
I think the hypothosis that different types to casein protein have different effects on health is interesting but so far does not have much evidence to support it. If you find certain cows milk products do not agree with you it is hard to say exactly why, blaming it on A1 casein is I feel a bit premature.
The following is a critical review of the subject of A2 and A1 milk published in 2006.
The second part of this review is a critique of the A1/A2 hypothesis. For both DM-I and CHD, the between-country correlation method is shown to be unreliable and negated by recalculation with more countries and by prospective studies in individuals. The animal experiments with diabetes-prone rodents that supported the hypothesis about diabetes were not confirmed by larger, better standardised multicentre experiments. The single animal experiment supporting an A1 beta-casein and CHD link was small, short, in an unsuitable animal model and had other design weaknesses.
The A1/A2 milk hypothesis was ingenious. If the scientific evidence had worked out it would have required huge adjustments in the world's dairy industries. This review concludes, however, that there is no convincing or even probable evidence that the A1 beta-casein of cow milk has any adverse effect in humans.
I also liked this paragraph:
Nutritional scientists have experienced the unreliability of correlation studies of food intake and chronic disease. It was earlier claimed that sugar consumption correlated with CHD (Yudkin, 1964); that countries' fat consumption correlated with breast cancer (World Cancer Research Fund, 1997) and that their meat consumption correlated with colon cancer (Armstrong & Doll, 1975). Closer human research has shown these associations to be spurious or uncertain (FAO/WHO Expert Consultation, 1998; Committee of Medical Aspects of Food & Nutrition Policy, 1998; Truswell, 2002).
There are also two letters sent replying to the review article. They provide some balance to the criticism in the review. The second one is from the guy who spends a lot of time promoting the A1 milk hypothosis.
on March 22, 2010
at 09:30 PM
From http://www.betacasein.org/index.php/pi_pageid/92 : "...This results in Holstein cows' milk containing on average a balance of 50% A1 beta casein and 50% A2 beta casein. Other breeds such as Jersey and Guernsey cows can have a higher proportion of A2 beta casein in their milk. This is due to more Jersey and Guernsey cows carrying the A2 compared to the A1 beta casein production trait."
My personal experience has been that Jersey is better for me than Holstein. http://texasprimalsurfwahine.blogspot.com/2010/03/342010-beta-casein-variants-and-n1.html That being said, Goat is working out even better for me personally!
on February 17, 2011
at 11:55 AM
I think it's a serious concern, so I eat A2 milk, goat milk, goat cheese, sheep cheese etc.
on February 16, 2010
at 04:10 PM
Just what I'm interested in!
- What products contain the A1 casein besides milk and cheese?
- Would I find A1 casein in sour cream or heavy whipping cream?
- How serious are the problems?
- What are the symptoms if you're having a problem?
- Is there any A1 casein in goat or sheep milk, cheese, or cream?
Thanks for the help.
on October 26, 2011
at 05:00 PM
Its a VERY serious concern and not always easy to get! "Beyond Organic" is a company by Jordan Rubin( CEO of Garden on Life) where you get this amazing beneficial A2 foods right to your door!! Check this out...