We look at the debate around goat milk vs cow milk vs sheep milk for babies, and examine the research on whether or not dairy causes colic, allergies, digestive disease and more.
Join any mom group on Facebook, or hit up any mid-day mom and tot music class with your little, and you’ll likely hear some chatter about what you’re feeding babe. First, it starts with the breast milk vs formula debate, and by 12 months, there’s a whole lot of shaming happening about what you’re putting into that baby bottle (or cup) next. I recently saw a YouTube video by a local nutritionist that sparked a huge discussion in the pediatric dietitian community about why she doesn’t give her daughter cow milk to drink. This isn’t the first time I’ve heard arguments against cow milk in favour of goat or sheep milk and there are a ton of claims on the internet fueling the goat milk vs cow milk debate. So we decided to get to the bottom of it in this post and help you make the decision about what kind of milk is best for your baby.
Claims About Goat Milk vs Cow Milk vs Sheep Milk for Babies
Before getting started looking at some of the popular goat milk or cow milk claims, I want to remind everyone that it is recommended by most pediatric groups that you can introduce milk as an ingredients as early as 4-6 months, however it is not advised to replace breast milk or infant formula with dairy milk completely until after one year of age. We talk about this in more depth here.
So what are people saying about goat milk, cow milk or sheep milk for babies?
Goat Milk vs Cow Milk on Improved Digestion
One of the most common cited benefits of choosing goat milk for baby is that it is apparently easier to digest than cow milk. Unfortunately, there isn’t a lot of research out there to compare how babies handle goat milk and cow milk compared with gold standard human breast milk, partly because current recommendations are to avoid giving infants under one year of age non-human milk or formula. It’s also super unethical to use babies as test subjects. However, there is some interesting research that has used simulated digestive tracts. One study used simulated digestive tracts to compare goat milk and cow milk and found that their proteins are actually digested pretty similarly. Another study compared different infant formulas (goat based and cow based) with human breast milk in simulated baby tummies, and found that the proteins in goat milk-based infant formula were digested a little bit more like the proteins in human breast milk. Not a huge difference, but it appears that the experience of drinking goat milk may be slightly more aligned with that of breast milk.
Now, let’s talk about what happens after a baby drinks milk – they poop. Examining your baby’s poop is often seen as a good way to determine how well foods (or in this case, milk) is being digested. While one study found no difference in the poop consistency of babies fed cow milk formula vs goat milk formula, and another found no differences in GI disturbances (like diarrhea) between babies fed goat milk formula compared with cow milk formula, one 200-participant study reported slightly more bloody baby bowel movements in babies fed goat milk formula group compared with cow milk formula. Overall, the number of bloody poops were pretty low, so it isn’t clear if this is a finding worth fretting over.
Goat Milk vs Cow Milk on Reduced Colic Symptoms
This is a common rationale I hear for why moms avoid dairy. In fact, this begins well before a baby is ready to drink milk themselves, with a lot of nursing mamas cutting out dairy in their own diets in an effort to improve their baby’s colic symptoms. But alas, that deserves a whole other post. While some moms may anecdotally SWEAR by removing cow dairy from their baby’s diet, research suggests that there’s no difference in how long baby cries or how easily they settle when comparing goat milk vs cow milk for babies.
Goat Milk vs Cow Milk on Improved Gut Microbiome
Sorry folks, we’re going to talk about poop again. In one study, some brave researchers decided to collect a bunch of poop from babies being fed either goat milk or cow milk formulas to study the bacteria in their poop. The researchers found that compared with babies fed cows milk formula, the profile of the bacteria in babies fed goat milk based formula was more similar to that of the breastfed babies. Translation? It’s possible that goat milk formulas inoculate the intestines with a colony of good bacteria more similar to that which you might see in breast milk fed babies.
Goat Milk vs Cow Milk on Iron Absorption
One of the major concerns about giving dairy milk to your baby before he or she turns one is that it might be replacing iron rich foods while supplying a high amount of calcium (which interferes with iron absorption). This, in turn, can put baby at risk for iron deficiency anemia. Well, compared with cow milk, one recent 2017 rodent study found that goat milk didn’t have the same interference with iron absorption. In fact, anemic rats given goat milk saw an increase in iron absorption, improved digestion and better metabolism of calcium. Of course, we need to use caution when applying these findings to humans, because, well…. we’re not rats. So even if goat milk does slightly aid increasing iron absorption, the more important variable is how often we’re offering iron rich foods from 6 months onward. Check out this awesome article for some helpful tips on starting your baby on solids.
Goat Milk vs Cow Milk on Immune Health
While you probably already know that breast milk can play an amazing role in the development of an infant’s immune system, some moms claim that goat milk can do the same due to its sialic acid content. Sialic acid is a component in mammal milk that helps activate the immune system and also helps with brain development, memory and digestion. Interestingly, the content of sialic acid in milk actually changes as time goes on. In human colostrum (mom’s first milk) there can be concentrations of sialic acid of up to 2000mg/L, and then it declines to about 200-300mg/L within just a few weeks. Although sialic acid is found in goat, cow and sheep milk, it is found in MUCH HIGHER levels in human milk. So the claim that goat or cow milk will help turn your Tiny Tim into Megamind doesn’t carry much evidence to support.
Sheep Milk vs Goat Milk vs Cow Milk on Kidney Health and Protein Content
When it comes to kidneys, there’s a lot of claims circulating around about cow milk putting too much strain on our baby’s kidneys. Goat milk and cow milk have about the same amount of protein (3-4% of every glass), while breast milk has significantly less (about 1%). Sheep milk comes in at a whopping 6% protein, which to us protein-obsessed adults sounds amazing, but too much protein might actually be dangerous for our little ones. MIGHT is the key here. It’s important to note that because it’s unethical to experiment on babies, we don’t actually know for sure how much is too much. Another challenge with this topic is that a lot of the research is now 10-20 years old and since goat milk and sheep milk have only recently become trendy, we don’t yet have a ton of the research to assess their safety.
One thing we can comment on is cow or goat milk-based formula since formulas are designed to mimic the nutrient profile of breast milk as closely as possible. As far as protein quality is concerned, there doesn’t seem to be any difference between goat milk and cow milk-based formulas. There is some evidence to suggest that the protein in goat formulas might be digested a little more like human milk as we previously discussed, but not enough to warrant tossing out any cow milk formulas you might have in the house.
Goat Milk vs Cow Milk on Allergies
When it comes to allergies, there’s a whole lot of information to cover. So much, in fact, that it’s probably better to leave most of it to some of our other blog posts (like this one and this one). In a nut shell (pun very much intended), current evidence seems to recommend introducing allergenic foods relatively early in your solids journey- somewhere between about 4-7 months of age (depending on your baby’s risks).
The evidence (here and here) also seems to suggest that most infants who are allergic to cow milk are also allergic to goat milk. This dispels the claim that goat milk is “less allergenic” than cow’s milk, and it is NOT a safe alternative when it comes to allergies. This allergy cross-over extends to infant formulas, too. Meaning, it would not be appropriate to give a child with a cow milk allergy a goat-milk based formula instead.
Goat Milk vs Cow Milk on Growth and Development
When it comes to physical growth, there doesn’t seem to be ANY difference between goat milk infant formula and cow milk infant formula and how well babies grow over the first six months of life. So, no, you don’t need to stress that little Charlie might not grow up to be a star in the NBA because you picked the “wrong” kind of formula.
One thing to note, however, is that in Canada and the United States, cows milk is fortified with vitamin D. Vitamin D is one of the really important reasons why we recommend cows milk for babies after 1! Since fortification of goats milk is not mandatory, not all goats milk products contain adequate vitamin D, so you will want to make sure you choose one that is fortified or you continue to supplement your baby’s diet with other cows milk dairy products, or other forms of vitamin D.
Why Do These Claims around Goat Milk vs Cow Milk Even Exist?
Is It The Lactose?
The first thing that comes to mind for me when I think about milk and digestion is “lactose”. Lactose is a kind of sugar that is found in milk and is made up of two smaller sugars called glucose and galactose. When we drink milk, an enzyme known as “lactase” cuts the tie between glucose and galactose to allow us to digest and mobilize the sugars.
Here’s a visual to help:
People who have lactose intolerance are lacking in the enzyme lactase, resulting in gas, bloating or diarrhea. It is therefore often suggested that the lactose content of milk can affect their baby’s tolerance and their risk for lactose intolerance. When we compare the lactose content of milks, we see that human breast milk contains around 7% lactose, while goat, cow and sheep milk contains around 4-5% lactose.
Babies are designed to live exclusively off breast milk or formula for the first 6 months, so lactose intolerance in infancy is very rare. It’s not until our enzyme lactase activity begins to decrease during our mid childhood (around five years of age) that we typically see this emerge. So since goat, cow and sheep milk all have lactose levels lower than breast milk, the lactose concern isn’t really a valid argument. At least not until mid-childhood, anyway.
Is it the fat globules?
One of the reasons people claim goat milk is easier to digest is because it contains smaller fat particles than cow milk, so it takes less effort for our bodies to break the fat up to use it.
The average diameter of milk fat globules in goat milk is 2.6 um, while average diameter in cow milk is 3.5 um. When we look at human breast milk, their fat globule average diameter clocks in to about 4 um and can actually increase in size throughout lactation. It is true that the fat globules of goat milk are smaller than those of cow milk and some scientists have speculated that these smaller fat globules might make it easier for our bodies to break down, I don’t think it’s a big enough difference (in light of the size of breast milk globules) to play a problematic role.
Is it the casein?
Another prominent argument against cow milk is that goat milk is easier to digest is because it contains more beta-casein and kappa-casein protein. Let’s explain what this means.
Milk is broken down into two proteins: whey and casein. Casein contains three sub proteins known as: alpha, beta and kappa which are found in different amounts depending on the species of animal.
Goat milk, for example, has more kappa and beta-casein compared to cow milk, which some say may be why goat milk is better digested. When we look at breast milk, we find that beta-casein is the major protein. This may be why some infants digest the protein in goat milk-based formulas better than cow milk formula since its protein composition is closer to that of human breast milk.
Let’s also discuss the rest of the diagram featured above, which is the different types of beta-casein: A1 and A2.
The main difference between A1 and A2 is a single amino acid (protein building blocks) which results in them being broken down differently. Interestingly, depending on their genetics, some cows produce milk with more A1 and others with more A2. Most milks on grocery shelves contain milk from a variety of cows so likely contain A1 and A2 and is likely labelled as A1 milk.
In the 90s it was suggested that A1 milk increased a person’s risk of developing cardiovascular disease and type 1 diabetes however there is NO convincing evidence that A1 beta-casein plays a role in the development of these conditions. Because of this fear mongering, some dairy producers are now developing A2 milk for purchase.
It is also suggested that A2 milk is better tolerated by people with intolerance to cow milk but at this time, there has only been a few small clinical trials in humans comparing A1 and A2. The takeaway message from this research is that A2 milk MIGHT produce less gastrointestinal symptoms in people with self-perceived milk intolerance, but we really need more research to know for sure.
Is it the pH?
Finally, a lot of people also make claims related to the pH of goat milk vs cow milk and suggest that goat milks is closer in pH to that of breast milk. It’s then further hypothesized that this pH has an impact on gastrointestinal disease. Unfortunately, it’s really hard to compare the pH of milks because their pH is constantly changing. To give you an idea, the pH of human breast milk actually changes as baby grows and the weeks of lactation progress and that pH is individual to each mother (confusing, I know). But because no one likes when I’m vague, here are some averages to examine.
By comparing these milks, you can see that goat milk is actually the furthest from human breast milk when it comes to pH, so to make the claim that goat milk eases digestion because its pH is close to breast milk actually holds no weight.
But, does pH have an impact on gastrointestinal infections?
A baby’s internal pH varies from the baby’s mouth to its stomach, and varies based on the length of its intestines, the presence/absence of food and the baby’s age (according to research here and here.) On top of that, the human body is actually really good at regulating our internal pH, if it wasn’t we would die from eating a lemon! So although the pH of the stomach affects digestion, we don’t yet have enough evidence to say if the pH of foods coming into baby’s stomach would influence infection rates.
Bottom Line on Goat Milk vs Cow Milk vs Sheep Milk for Babies
There have been a number of claims surrounding the superiority of goat milk over other milks, but the majority of these claims have very little sound evidence.
Whether goat milk actually improves digestion is still unclear. Some of the proteins in goat milk may be digested similarly to human breast milk, however studies have not found any difference in a baby’s poop depending on the milk and it did not reduce colic symptoms.
When it comes to gut health, some studies have shown that goat milk formula may populate a babe’s gut with good bacteria more like that of human breast milk.
An interesting study did find that goat milk may help to increase iron absorption, but most of those studies only contained rats so it’s not fair to generalize those effects in human babies.
Some people claimed that the sialic acid in goat milk can aid in the development of a baby’s immune system, however it’s found in much higher levels in human breast milk.
Finally, there doesn’t seem to be any difference between goat milk and other milks when it comes to how well babies grow over the first six months of life.
Bottom line is that cow milk is considered safe and nutritious for healthy babies over 1, and we have the most research to support its use compared with other milks. It’s also a lot more economical and easy to find compared with goat milk or sheep milk. Personally, my son is drinking breastmilk until the supply runs dry, and then I have no qualms about switching him to whole cows milk (assuming he likes it). Ha, my hubby (who LOVES whole milk) is very excited to have more of it in the fridge. Either way, you should speak to a RD or your pediatrician about what you’re going to feed baby after you ween.
Hopefully this article has helped clear up some of the questions you had about all the different milks that are out there, because there certainly are a lot! Ultimately, though, the decision to choose what to feed your baby is deeply personal and it’s up to you to decide what you feel is best for you, your baby, and your family.
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Karen Hutchinson, Dietetic Practicum Student
Edited By Sofia Tsalamlal, RD, MHSc Nutrition Communication