A friend of mine emailed this to me yesterday, I emailed her back asking for the link:
Udderly New Insight About Milk and Autism:
An Emerging New Hypothesis on A1 and A2 Beta-Casein by Julie Matthews, Certified Nutrition Consultant
As an autism nutrition consultant, I've been supporting clients following the Gluten-Free Casein-Free (GFCF) diet for years. Some of my clients would report that their child could handle goat's milk or raw milk without allergic reactions. I began to wonder if all milk was created equally.
I conjured various theories: could the protein in goat's milk be different than cow milk, was it the pasteurization process (absent in raw milk) that made the difference, was it something else, or a combination of factors? Then, one of my clients introduced me to A1 and A2 beta-casein.
There are various types of casein. Goat's milk, as well as sheep and buffalo milk, contain A2 beta-casein. Raw milk, while often from cows, is typically produced from small herds of Jersey and Gernsey cows, both of which contain a high percentage of A2 beta-casein compared to most dairies that use mainly Holstein cow's that produce a majority of
A1 beta-casein. Here's what I have learned through my research about casein and A1 versus A2 beta-casein.
Beta-casein is a protein that contains bioactive peptides and opioids.
Bioactive peptides are important for protecting the undeveloped immune system of newborns, and stimulate the growth and development of organs like the gastrointestinal tract and gut. Bioactive peptides have also been shown to kill bacteria that normally cause immune system infections. Opioids have pain-killing effects, sedative properties, induce sleep, and play a role in the control of food intake.
Opioids can be produced by the body in the form of endorphins, or be absorbed from digested food, such as milk and wheat, in the form of casomorphins and gluteomorphins (opioid proteins). Several forms of beta-casein exist and make up 25-30% of the proteins in cow's milk.
There are approximately 13 beta-casein variants, with A1 and A2 variants being the most commonly occurring. A1 beta-casein contains the amino acid histidine at position 67 in the protein, while A2 beta-casein instead contains the amino acid proline at the same position. Studies have shown that when digested, A1 beta-casein breaks down to a casomorphin protein called beta-casomorphin-7 (BCM7). This is a direct result of the histidine amino acid that A1 beta-casein contains, as A2 beta-casein does not form BCM7 (1).
Several enzymes in the digestive tract process beta-casein including DPPIV, (dipeptidyl peptidase IV) and cause the break down of bioactive peptides and opioids. Studies suggest that the digestion of cow's milk (containing A1 beta-casein), leads to the release of opioids, such as BCM7, and can cause harmful effects in children with autism (2) where DPPIV function may be impaired. As this amino acid structure is more difficult to breakdown, those with compromised or weak digestion may accumulate opioids more readily.
Additionally, when the gut is "leaky" (referring to increased gut permeability), these opioids end up in the blood stream in much greater concentrations than in those people with a healthy gut wall that does not leak. BCM7 is not produced when A2 beta-casein is digested, so goat's, buffalo's, and sheep's milk that contain A2 beta-casein but not A1 beta-casein should not cause these harmful effects. There are other opioids that may also be formed; however,
BCM7 appears to be the strongest.
As Jon Pangborn, Ph.D. describes, the enzyme DPPIV, which is also called CD26, has several other functions in the body, including involvement in signal transmission via lymphocyte receptors, and assisting the enzyme, ADA, in processing adenosine as an ADA binding protein. DPPIV is impaired by toxic heavy metals like mercury, lead and cadmium, a milk allergy, organophosphate insecticides, and yeast.
Children with autism have greater toxic metal burdens, and one theory is that these heavy metals knock out this DPPIV enzyme, and the impaired DDPIV leads to improper processing of dairy and wheat. A supplemented plant analog version of DPPIV cannot substitute for the animal version completely, but it can certainly help.
While it is possible that A2 milk may also release opioids, Japanese and German scientists were unable to release BCM7 from A2 milk (1, 3).
It appears that human breast milk may not release BCM7 either.
Interestingly, this may explain why breastfeeding does not seem to cause a casein reaction to sensitive babies when dairy is avoided in a mother's diet. In addition to affecting autism, research suggests that
BCM7 may lead to the onset of several diseases, such as heart disease, diabetes, and schizophrenia (4).
Studies have also shown that wheat products, which contain gluten, also cause health problems for children with autism (5) Gluten has long been established as a problematic protein for many individual, most well studied in celiac patients, causing inflammation in the gut, diarrhea, constipation, abdominal pain, digestive problems, and the improper absorption of nutrients. Similar responses are seen in many children with autism (that are not diagnosed with celiac). Gluten, along with an autistic person's already compromised digestive system, can exacerbate the ability of the body to break down beta-casein.
Scientists believe that opioids like gliadomorphin (a gluten opioid) and BCM7 (a casein opioid) are toxic for children with autism due to the fact that these children have an abnormal, leaky, gastrointestinal tract (6). Instead of completely digesting and excreting these opioid proteins, some of the partially digested gluten and casein proteins leak out of the gut and are transported to other parts of the body before they can be completely digested. These opioid proteins travel through the bloodstream, cross the blood brain barrier (the barrier between the brain and the rest of the body), enter the brain, and stimulate morphine-like effects. Casein proteins (BCM7) negatively affect the brain by causing inattentiveness, unclear thinking, and irregular sleeping and eating patterns (7).
In children with autism, gliadomorphin and BCM7 can also cause the release of histamine, a chemical that regulates immune cell communication. Histamines are normally released in the body in response to an allergic reaction. This mis-regulation of immune cells weakens the immune system's ability to ward off harmful viruses and bacteria that cause diseases. This is consistent with the experience that many children with autism get frequent infections and illness.
Antibodies are also released to help target and remove unwanted opioid proteins. IgA is an antibody that can be found in blood, saliva, tears, and mucous membranes of the respiratory system and gastrointestinal tract. IgG antibodies are the most common antibodies in the body, and can be located in all bodily fluids. IgG antibodies are the only form of antibody that can cross the placenta in pregnant woman to protect a fetus (unborn baby). IgG antibodies also play a major role in fighting viral and bacterial infections. When the immune system detects foreign particles such as viruses, bacteria, fungi, or cancer cells it stimulates the production and release of antibodies.
These antibodies attach to the foreign particles, labeling them as hazardous so that they can be destroyed and removed from the body (8).
So while the peptides from casein or gluten trigger an IgG immune response, the opioids trigger an IgA immune response. So it is not just opioids that trigger an immune response, casein and gluten protein can do so also, just using different types of antibodies.
Studies have shown that in autistic and schizophrenic patients, large amounts of gliadomorphin and BCM7 can be detected outside the gut (8).
This further indicates that their bodies are not able to properly break down and utilize these opioid proteins. These studies also showed that in 86% of schizophrenic patients, IgA antibodies that were targeting gluten were released into the body, and 67% had IgA antibodies that were targeting casein. In patients with autism, approximately 30% of the patients had IgA antibodies targeting gluten and casein present in the body. The release of IgG antibodies targeting gluten and casein were also detected in these patients. More than 80% of the autistic and schizophrenic patients had elevated levels of IgG antibodies in their blood.