Eliminate or Introduce Early To Prevent Milk Allergy in Children?


Milk is the second most common food allergen in the U.S. according to the CDC, and it provides a good test case to assess two competing models for the prevention of food allergies in children. The traditional approach is the elimination model used by practitioners like Dr. Kenneth Bock, author of Healing the New Childhood Epidemics: Autism, ADHD, Asthma, and Allergies in which allergenic foods are removed from the child’s diet and avoided. The elimination approach has a long record of reducing not only food allergies, but also asthma, ADHD and autism—suggesting they are all related to immunity. A new model for preventing allergies has recently emerged from immunology that encourages parents to introduce allergenic foods early—between 3 months and 3 years, starting concurrent with breastfeeding—in order to prevent children from developing food allergies by teaching their immune system to tolerate allergenic foods early in life. Let’s compare both approaches in the case of milk to assess risks and benefits.

The two approaches

The early-introduction model takes an interventionist approach that assumes children’s inflammatory immune response to a food allergen is aberrant, and attempts to improve a child’s natural immunity by manipulating it early on before it becomes reactive with the environment. The age of the early intervention starts at 3-4 months, when infant immunity is protected by mother’s breastmilk—normally the only food source at that age. The model introduces allergenic foods like peanuts, milk, eggs and wheat gluten in small doses three times a week over the first 3 years of life starting at month 3 or 4—before infants’ immune systems are developed enough to mount an immune response. The theory is that children will gradually learn to tolerate the food allergens, if exposure starts during breastfeeding when infants' immune systems are undeveloped. Studies in the U.K. that followed 1,300 children to age 3 showed a reduction of food allergies in 67% of the children introduced early to milk who remained in the study after 43% opted out (to see the opt-out stat, scroll down to the EAT STUDY, click on “Study 2” that included milk, and then click on “Read more”). The most common reasons for opting out was the child’s refusal to eat the allergenic foods, the mother being unable and/or unwilling to enforce it, and a lower quality of life. The high dropout rate leaves us wondering if 43% of the children in the studies who opted out were avoiding milk and other allergenic foods because they caused an allergic response. Because of the design of the study, we cannot know the answer to that question.

The elimination model takes a natural approach, in the sense that all mammals naturally evolved to avoid foods that make them sick. The assumption is that a food allergy is not a result of an aberrant immune system, but rather a healthy immune response to a food allergen that should be avoided for environmental reasons. Avoidance of an allergen is our body’s natural response to feeling sick after eating allergenic foods. There’s primitive somatic logic at work in that stimulus-response: you eat a food you’ve never eaten before, you get sick, and the next time you see that food, unless you’re starving, you’d rather not. You have a body memory of feeling sick after—inflamed, bloated, nauseated, agitated, sick to your stomach, drooling, runny nose or even with diarrhea, vomiting or anaphylactic shock. You may also have an emotional response with your memory of the allergenic food, and feel afraid of or repulsed by the smell or sight of it, and keep your distance. The elimination model for preventing food allergies assumes the problem is environmental, and encourages parents to avoid allergenic foods in the environment that trigger the inflammatory immune response in children. Thus the elimination diet typically excludes from the child’s diet the most common allergenic foods—peanuts, casein, gluten, eggs.

These are two totally different approaches. One is minimally invasive. One is more invasive because it requires introducing the most allergenic foods early during breastfeeding when infants normally would not eat them or be exposed to them. How do we know which approach is better and safer in the long run for children? Let’s test the two approaches in the case of the second most common food allergen in the U.S.—milk—and see which has more benefits and fewer risks.

Issue 1: Casein Protein

The first problem has to do with casein protein variations in mammalian breast milk. Human breast milk contains A2 casein protein that humans can easily digest. Goats, brown Jersey cows, Asian cows and African cows also produce A2 casein in their breast milk. The problem is that the most prevalent dairy breed in the U.S. is the black and white Holstein Cow that produces A1 casein protein. Holstein’s have also been interbred with Jersey cows, creating cows that produce both A1 and A2 casein in their milk. If the fundamental issue underlying milk allergies is that humans cannot easily or effectively digest A1 casein, then training infants' undeveloped immune systems not to respond to it doesn’t really solve the problem, does it? Their immune system might be trained not to launch an inflammatory immune response, but some children may still struggle to digest the A1 casein protein in Holstein milk, and that could set them up for digestion and absorption problems and gutbrain inflammation later, increasing their risk of autism, ADHD and asthma.

Traditional wisdom says to breastfeed as long as possible to support your child's development of natural immunity, introducing cow milk only after year one when babies’ digestive systems are matured enough to digest the more dense proteins in cow’s milk. We know enough now to update this traditional wisdom in regard to what kind of milk to introduce. In regard to A1 casein, the older elimination model makes more sense than the early-introduction model. Eliminate the A1 casein that is allergenic, rather than manipulate the child’s underdeveloped immune system to not respond to it. How do you do that? Some mothers choose goat milk over cow milk to avoid A1 casein and the milk allergy and digestion problems associated with it. Other mothers source cow milk from trusted organic farmers whose herds include only purebred brown Jersey cows that produce A2 casein. Still other moms avoid milk altogether, and prefer yogurt because the casein protein is already broken down, making it easier to digest than milk.

Issue 2: Pasteurized Milk vs Raw Milk

Compared to raw milk, pasteurized milk is harder to digest, more inflammatory, more nutrient-depleted, and more allergenic, because cooking milk destroys the enzymes that breakdown casein proteins and denatures the natural milk fats and Vitamin D that deliver bioavailable calcium to healthy bones, teeth and heart. While the benefits of raw milk are well established, if the milk you buy is pasteurized, even if it is organic, it is allergenic as well as nutrient-depleted—unless “fortified” with synthetic forms of nutrients naturally available in raw milk, including Vitamin D and calcium. Pasteurized milk is inflammatory, and raw milk is anti-inflammatory. Training children’s immune systems not to respond to pasteurized milk doesn’t make the milk less inflammatory or allergenic. So if you want to introduce milk to your child, another choice you have is whether to buy pasteurized or raw. And for all the reasons we’ve already discussed, the choice to choose raw milk depends entirely on knowing a dairy farm with strictly Jersey herds that pasture grazes, is upstream of commercial runoff, that you can trust with your child’s health. Thankfully there are independent farms like that in every state. Look for them and you will find them. They need your financial support as much as you need their quality raw dairy products.

Issue 3: Pathogenic Bacteria in Milk

This issue has to do with the failure of pasteurization to kill pathogenic antibiotic-resistant bacteria that have evolved on commercial dairy farms. One of these dangerous heat-resistant and antibiotic-resistant microbes is known as MAP (mycobacterium subspecies avium tuberculosis), and it’s been found live in 2% of pasteurized milk cartons on grocery store shelves. The bacterium evolved from the same species that causes tuberculosis and leprosy, and it has survived even ultra-high pasteurization. MAP poses a serious public health threat because it causes a gut wasting disease in cows known as Johne’s disease and Crohn’s disease and irritable bowel syndrome in humans. Given the risk of MAP contaminated milk, early introduction of pasteurized milk that may be infected with MAP before your baby can mount an adequate immune response may reduce the risk of milk allergy but increase risk of a gut infection associated with irritable bowel syndrome, ulcerative colitis and Crohn’s.

Moms who prefer goat milk need to know that, sadly, MAP can infect goats too, though it’s much more common in cattle. Infection of goats is through wastewater runoff from dairy farms into local waterways, so if you want goat milk, source from farms that are upstream and more isolated, with well established healthy herds. Interestingly, it took a long time to identify MAP as the culprit in milk, because it moves around as pus, meaning it has no cell wall, and the standard test for the presence of bacteria before MAP was a stain test that shows a cell wall. The U.S. allows more pus in Grade A milk than any other country in the world. As with the A1 casein issue and the issue of cooked milk’s inflammatory and allergenic qualities, the problem of pathogenic bacteria in pasteurized milk is also environmental. While organic farming and pasture-grazing greatly reduce the risk of MAP in cows, the problem has been exacerbated by wastewater runoff into local waterways, and the tendency of desperate dairy farmers to sell herds they know have been exposed without warning buyers of the risk of contamination. So while organic milk reduces the risk of MAP, it offers no guarantee.

Which approach is safer?

The avoidance model that assumes the problem is environmental and focuses on eliminating or reducing exposure to environmental antigens is safer for preventing milk allergy than the early introduction model—given the risk of both A1 casein exposure and MAP exposure in breastfeeding infants who would not normally be exposed. Training a child's immune system to tolerate these antigens doesn’t diminish the negative impact of the them on a child’s overall health, including gut health. Here’s what we’re left with after our assessment.

  • Mothers' breast milk is best for reducing food allergies and bolstering babies’ immune health. Nurse as long as you can, and if nursing ends sooner than you like, human breast milk from a donor mom is the healthiest and least allergenic option for your baby.

  • The next best option would be raw organic goat milk or goat yogurt from organic farms that aren’t downstream from waterways that might be contaminated by commercial dairy farms.

  • Next best to goat milk would be raw organic cow milk or yogurt from pasture-grazed Jersey herds that produce only A2 casein in their milk—if sourced from upstream farms isolated from commercial farm runoff that might be contaminated with MAP.

  • The fourth option is to exclude milk from the child’s diet after the age of breastfeeding is over—especially if the child shows signs of an allergic response. Genetics will weigh in on this last decision. If a child’s ancestors were fishermen, for example, sourcing fat from fish oil rather than milk, the child may naturally show little interest in drinking milk after infancy.

Without longitudinal studies to determine longterm overall health outcomes, it’s hard to trust the premise that it’s healthier to introduce pasteurized milk, even organic, during the vulnerable period when children’s immune systems are undeveloped—even if a tolerance for this allergenic foods could be demonstrated in children who were able to complete the study after 43% opted out. Because these preliminary studies stopped at age 3, we cannot know what health issues might emerge later in life from introducing allergens at 3 months of age. Also since 43% of the children in the study dropped out, mostly because they wouldn’t eat the allergenic foods, we are left with a lot of unanswered questions. Until more information is available, the natural elimination approach to reduce children’s exposure to food allergens in the environment seems to offer greater benefit and safety. In other words, avoid allergens in the child’s environment, rather than ask a child to adapt to allergenic and contaminated foods beyond the capacity of her or his natural immunity.