When we buy and drink our dairy milk, how many people actually think about which type of cow produced it? I am willing to guess it is not many but according to research and a number of claims by experts, the health benefits of your milk might well depend on which type of cow it comes from.
You may have noticed A2 milk on the shelves and may also have seen some of the marketing claims that A2 milk is better for you than regular milk. The producers claim that A1 has several benefits over and above regular milk and also claim that it is easier for people with lactose intolerance to digest.
There is however considerable disagreement regarding the health benefits of A2 milk and the potential risks of drinking ordinary milk. This article will take a detailed look at the claims and the scientific evidence to support them.
What is the Difference Between A2 Milk and Regular Milk?
Casein makes up the bulk of the proteins found in your milk with some 80% of the milk’s protein content coming in the form of casein. There are actually several forms of casein found in milk with beta-casein being the second most common.
There are actually 13 different types of beta-casein but the two most prevalent are A1 beta -casein and A2 beta-casein. So what is the difference between the two and what impact do they have on your health?
- A1 beta-casein : The majority of milk that we drink is produced by breeds of cow that originally came from northern Europe. These cows include Friesian, Holstein and Ayrshire cows. The milk they produce is typically higher in A1 although it also contains A2 beta-casein.
- A2 beta-casein : The milk which is higher in A2 is produced by different breeds of cow which originally came from Southern France and the Channel Islands of Jersey and Guernsey. These breeds of cow include Chaolais, Limousine, Jersey and Guernsey cows.
The regular milk you drink is higher in A1 beta-case but it also contains A2. However A2 milk does not contain any A1 beta-casein. The reason for this ongoing debate is that some studies have revealed that A1 might be harmful to your health and that A2 is a healthier and safer option. The A2 Milk Company which produces and markets A2 milk also claims that their milk provides health benefits over and above regular milk including digestive benefits, treating autism and diabetes.
The Potential Risks of Regular Milk
We have long been told that milk is good for you but over recent years, studies have started to reveal that drinking regular milk may not be as healthy as we were led to believe. One of the main reasons for this is the presence of beta-casamorphin-7 which we will refer to as BCM-7.
BCM-7 is a type of opioid peptide which gets released as A1 beta-casein is digested. Several population studies have indicated that BCM-7 could be harmful to human health and made a potential link between consumption of regular milk and increased risk of disease including heart disease. (1)
It is possible that BCM-7 affects a person’s digestive system but the extent to which it gets absorbed intact into the blood remains unclear. No studies have been able to find BCM-7 in healthy adult blood after they have drunk regular milk but several studies have found that it might be present in babies and very young children. (2) (3)
The following risks have been associated with the consumption of regular cow’s milk and with A1 beta-casein in particular. These potential risks are the basis of the claims that A2 milk is a healthier option.
1) An Increased Risk of Heart Disease
A1 milk may increase your risk of developing ischaemic heart disease. While the evidence is not overwhelming, two observational research studies did indeed link A1 milk consumption to an increased prevalence of heart disease. (4) (5)
One study done on rabbits support these observations. The researchers found that rabbits that consumed A1-beta casein experienced a buildup of fat in damaged blood vessels which was much greater than rabbits given A2 beta-casein. (6) An accumulation of fat could cause blood vessels to become clogged and result in heart disease.
Only two clinical trials have been done on humans to evaluate the link between A1 milk and heart disease. Neither study found that there was any significant difference between the volunteers given A1 or A2 beta-casien in terms of risk factors including blood fats, blood pressure and cholesterol. (7) (8)
Currently there is insufficient evidence that the risk of developing heart disease is any greater in those who consume A1 milk.
2) Type 1 Diabetes Risk
This type of diabetes characterized by an insulin shortage is usually diagnosed during childhood.
There have been several observational studies that indicate the consumption of A1 milk in childhood can increase the chance of developing type 1 diabetes. However the limitations of these observational studies need to be taken into account. They are unable to prove a direct link between A1 milk and the disease. (9) (5)
Several animal studies have been conducted with conflicting results. Some indicate that A1 beta- casein has an adverse effect on the disease while others have demonstrated a protective effect. Other studies indicate there is no difference at all between A1 beat-casein and A2. (9) (10) (11)
3) Sudden Infant Death Syndrome
Sudden infant death syndrome is defined as an unexplained infant death with no apparent cause. It is the number one cause of death for infants under the age of one.
Experts have speculated BCM-7 could be involved in SIDS and researchers have put the theory to the test. In one study, researchers found a high level of BCM-7 present in the blood of babies that stopped breathing temporarily during (sleep apnea). This is significant since sleep apnea has been linked to the increased risk of sudden infant death syndrome. (12)
There has also been speculation that peptides such as BCM-7 could be a contributing factor to developing autism.
One study published in 2009 found that children fed A1 cow’s milk had a higher level of the peptide in their blood than infants who were breastfed. These levels did however drop very quickly after they stopped drinking in some children. For the children who did not experience a drop in BCM-7 levels, the presence of the peptide was strongly linked to autistic symptoms like the inability to plan and to perform certain tasks. (13)
Another earlier study indicated that the consumption of cow’s milk by infants could worsen many of the symptoms of autism. (14) However, other studies have not demonstrated the link. (15)
5) Digestive Health
Many people are affected by lactose intolerance which is characterized by an inability to property digest the sugar in cow’s milk. The condition causes various digestive symptoms like gas, bloating and diarrhea.
While the level of lactose in both A1 milk and A2 milk is exactly the same, some people say that the A2 variety does not cause as much bloating.
One study did lend support to the claims that A2 milk is better digested. The study which used 41 volunteers found that A1 milk caused people to produce softer stools compared with those who drank A2 milk. (16)
Animal studies have also found that A1 could cause a significant increase in digestive system inflammation. (17)
The research into the relative merits of A1 and A2 milk is still ongoing and it is very difficult to draw any conclusions yet.
Some people may find they can tolerate the A2 variety better which is good enough reason to stick with it. However when it comes to the potential dangers of drinking regular A1 milk, the evidence is still too weak to cause great concern.