Is Milk Really Doing Your Body Good? Maybe Not!


In my first year back in college, I had to take an introduction to food science class. The culminating assignment for the class was to create a themed menu and then prepare and share the food with our classmates. My project partners were Christine and Samantha, and we decided to do a dairy-free menu because Sam is allergic to dairy. When she first suggested a dairy-free menu, I looked at her very confused and said, “You mean, you’re lactose intolerant?” She patiently and sweetly (as is her way) responded, “No, I mean I’m allergic to dairy.”

I was so lost as I had never heard of a dairy allergy before! And, honestly, it took me f-o-r-e-v-e-r to remember that she has a dairy allergy because the concept was completely foreign to me. Even though I knew milk is one of the top eight allergens, for a long time, I thought of a milk allergy as being only an allergy to milk because I didn’t understand how allergies actually work. (If you ever read this, Sam, I apologize!)

Oh, how far I have come in my understanding of physiology and (some of) the millions of ways nutrients interact with us from our taste buds to our DNA. I now know that absolutely any food can cause problems, depending on the individual. (I’ll have to tell you about my apparent sensitivity to rice some time.)

But there are still some foods that are more likely to cause problems than others. And, for the moment, the two that come up time and again are gluten and dairy. Since I’ve already covered gluten in-depth, it’s time that we talk about dairy because I constantly watch lightbulbs go off for clients when they finally recognize that our insistence on consuming dairy may be causing more symptoms than we realize.

So, let’s start at the top. Or if you aren’t interested in all the science, you can jump straight to the discussion about impact. (Although I can’t possibly imagine that you don’t want to understand exactly how dairy impacts the body, so I’ve included it.)

What do you mean when you say “dairy”?

When I talk about dairy, I am always referring to a product made from animal milk. Beyond the actual milk itself, dairy products include anything made from it, like yogurt, kefir, butter, ghee, cheese and ice-cream. Since the process of making these products results in a number of nutrient changes, let’s talk about the basic macronutrients in milk… and believe me, this is important later when we talk about how dairy affects the body.

In its natural state, animal milk contains a bunch of water (~87% by volume),  carbohydrate (the disaccharide called lactose), protein (primarily as casein and whey) and fat (mostly saturated fat, but also smaller amounts of monounsaturated, polyunsaturated, and trans fats).

Oh! You didn’t know that trans fats can occur naturally? Well, now you do! It is worth noting, however, that there is no evidence that naturally occurring trans fats have the same impact in the body as the manufactured variety. But I digress…

To turn milk into yogurt or kefir, bacteria are introduced and they ferment the lactose. Fermentation is really just bacteria “eating”, or whatever they do since they don’t have mouths. In the process, the bacteria stay alive consuming some, but not all, of the lactose and then we eat the probiotic food to get those helpful little microbes into our guts.

For making cheese, first an acidifier is added to the milk, which turns the lactose into lactic acid. Then rennet is added. Rennet is an enzyme that causes some proteins in milk to curdle (the casein) and others to liquify (the whey) so they can be separated and the curd can eventually be dehydrated into the somewhat solid mass of deliciousness known as cheese. As it relates to the macronutrients, the end product has very little carbohydrate, all the protein from the casein, and all the fat that was in the milk to start with.

The point of this short and overly simplified food science lesson is to say that all dairy products do not have the same macronutrient profile as milk, and this is significant when we start talking about digestion and what dairy does in the body.

What are the differences between different animal’s milk?

For those of us in the US and many European countries, the main dairy animal is the cow, followed by goat, sheep and buffalo (although goat milk is far more popular globally than cow milk). Also, I have heard that camel milk is a thing for some people (I just haven’t had the opportunity to try it), and I am aware that there is an adult market for human breast milk. But that is beyond the scope of this article for a very large number of reasons!

Since cow and goat milk are the two most common, I will use them to talk about the differences. To start, both contain the same basic nutrients of lactose, casein, whey and fats. Because lactose is always a disaccharide made of galactose and glucose, the lactose structure is the same in both milks. That being said, goat milk does contain only 4.1% lactose by volume compared to 4.7% in cow milk. It’s probably not a big enough difference to cause fewer symptoms if you are lactose intolerant, but still worth noting.

Now moving onto more interesting (and potentially significant) differences…

Goat milk primarily contains five proteins: α-lactalbumin and β-lactoglobulin (which make whey), κ-casein, β-casein, and αs2-casein. Cow milk has similar proteins to these five. However, cow milk’s most abundant protein is βs1-casein and this particular protein is virtually non-existent in goat milk (keep this in mind for later when we talk about how dairy impacts the body).

As well, the fat content between the two milks is different. For one, the size of the fat globules in goat milk are smaller which is likely because there is no agglutinin. Agglutinin is a general term used to describe substances that cause other substances to clump together. In the case of cow milk, the agglutinin causes the fat globules to clump together. This is why cow milk is homogenized the process “unclumps” the fat globules so they remain dispersed in the liquid part of the milk and don’t form a layer of cream on top.

Finally, goat milk has more fat by volume than cow milk. However, goat milk has a significantly larger proportion of short- and medium-chain fatty acids than cow milk. The four medium-chain fatty acids (caproic, caprylic, capric, and lauric acids) make up 15% of the fat volume in goat milk, but only 9% in cow milk.

How well is dairy digested?

If you are lactose intolerant, it means that you do not produce the enzyme (lactase) necessary to break lactose into galactose and glucose. The end result is that the undigested carbohydrate gets to the very helpful bacteria living in your intestine and they have a party chewing up all that goodness that you couldn’t handle.

(For the record, 65% of the non-infant/toddler population has a reduced lactase production, meaning that most of us struggle at least a little bit to digest the lactose in dairy products that contain it. Lactase deficiency is most common in people of East Asian, West African, Arab, Jewish, Greek, and Italian descent.)

The casein and whey in dairy products are generally broken into peptides (or smaller pieces of partially digested protein) in the stomach. These peptides enter the small intestine where they are, in theory, further divided into groups of one, two or three amino acids for absorption into the blood stream.

However, there are two important notes about this protein digestion. The first is that casein takes a considerably longer time to digest than whey does (6+ hours vs 3 hours, in one study). That means products containing casein will slow down the entire digestive process, especially in those who are not particularly good at digesting protein. The second thing is that the length of peptides resulting from stomach digestion are different, with casein being broken into more peptides that are 30 – 60% shorter than the whey peptides. As a result, more pieces of casein enter the small intestine than pieces of whey protein.

Regarding the digestion of dairy fat, some people believe that even after homogenization of cow milk, the smaller fat particles in goat milk make it easier to digest. I couldn’t find any proof that this is true as, in theory, homogenization (which is a purely mechanical process) reduces the size of the fat globules in cow milk and would yield them easier to digest.

However the fat in goat milk may be easier to digest because of the presence of more short- and medium-chain fatty acids. These shorter carbon chains require less breakdown by the intestine and can be absorbed directly into the blood stream rather than having to be transported via the lymphatic system, the way long-chain fatty acids must be. Plus, the short-chain fatty acids are the primary fuel source for our intestinal cells so they get absorbed and used straight away.

Of course, I also wonder if the presence of agglutinins in cow milk cause any digestive or other problems. Unfortunately, I couldn’t find any answers to that question either.

(Do you ever get the feeling that the lack of research on a topic is related to how important our government thinks a food is for our health?)

Okay, I get it, you like science… so how does dairy impact me?

I’m so glad you asked!

1.  The lactose, casein, whey, and/or fat in milk can trigger an intolerance if you do not make enough of the enzymes necessary for digesting the various macronutrients.

If your problem is just the lactose, you may be able to consume dairy products that have less lactose (as discussed above) or take lactase capsules and continue happily eating dairy. Be mindful that not everyone responds well to taking enzymes like lactase. As well, if you have tried lactase and you still don’t feel good when you consume dairy products, keep reading…

If you struggle to digest the proteins and/or fats, consider switching to goat or sheep milk and see if the removal of βs1-casein and the shorter fatty acids make it possible for you to digest. If that doesn’t work, you can work with a healthcare professional to identify a digestive enzyme supplement that can help with the proteins and/or fats. Or, you can stop torturing your body with foods that it can’t handle and get the nutrients from other sources.

2. Because dairy contains various proteins and peptides, they can trigger food allergies.

If you have an IgE-mediated allergy to dairy proteins, I have no doubt that you are already aware of it and are avoiding dairy. If you’re not, you should… no one needs extra inflammation in their body triggered by a food!

3. Also because of dairy’s proteins and peptides, any one of them can be the cause of a milk sensitivity.

Casein and its peptides (primarily) and whey and its peptides have been shown to trigger food sensitivities in people. Before I get into the specifics, remember that your immune system can respond to any part of any protein. In other words, you may have a casein sensitivity or a whey sensitivity or a casein-fraction sensitivity or a whey-fraction sensitivity. If you have a sensitivity to βs1-casein or one of its fractions, then switching to goat or sheep milk may resolve your issues. However, if you have a sensitivity to αs2-casein, then changing won’t help because this protein is in the milk of multiple animals.

Because of many types of proteins, milk is one of the top eight food allergens and some doctors estimate that 50% of people who are sensitive to gluten are also sensitive to dairy. (Of course, there are people who are not sensitive to gluten who are sensitive to dairy.) This is why all elimination diets include the removal and reintroduction of dairy.

Unfortunately, it is difficult to estimate how many people are sensitive to milk proteins because it is often mistaken for lactose intolerance and can manifest in symptoms outside of the digestive tract. For example, in a study of infants and children, 37% of those with atopic dermatitis (aka, atopic eczema) and no other food allergy symptoms tested positive for a cow milk allergy. I’ve even had a client whose infant had eczema while she was breast-feeding. When she significantly lowered her dairy intake, her little boy’s eczema went away!

Gastrointestinal (GI) symptoms that can be caused by a milk / dairy sensitivity include:

  • Abdominal pain
  • Constipation (Note: This one is quite common. If you or your child are constipated, I highly recommend switching to goat or sheep milk products to see if there is an improvement. If not, change to non-dairy products like almond milk or coconut milk.)
  • Crohn’s disease and ulcerative colitis
  • Diarrhea
  • Gallbladder problems
  • Gastritis
  • GERD / acid reflux
  • IBS
  • Pancreatitis
  • Rectal bleeding

Remember when I said that eating should not hurt? I meant it!

Of course, dairy sensitivity can manifest outside the GI tract as well. These symptoms include (but are definitely not limited to):

  • Hypertension / high blood pressure
  • Eczema
  • Autoimmune diseases, such as psoriasis, multiple sclerosis, rheumatoid arthritis and lupus
  • Hives / urticaria
  • Meniere’s disease
  • Nosebloods
  • Earaches
  • Sinusitis
  • Vertigo
  • Epilepsy
  • Migraines
  • Asthma
  • Frequent urination
  • Urinary tract infections (UTI)
  • Colic
  • Fatigue
  • Food cravings
  • Halitosis / chronic bad breath
  • Insomnia / trouble sleeping
  • Obesity
  • Bruxism / teeth grinding
  • Pain, such as in the back
  • Mood changes such as anxiety and depression

Now, I want to make one last really important point on this topic…


I emphasize this because I have worked with people who have a lactose intolerance and believed that by taking lactase, they were solving their problem. That might have been true for some GI issues. However, when we removed dairy from their diets, other symptoms went away as well. It turns out they were in the majority of people who don’t make enough lactase to break down the carbohydrates and they are sensitive to dairy proteins.

If you are one of these people, your sensitivity will flare up any time you eat a dairy product that contains the protein to which you are sensitive. For most people this is a casein sensitivity, although it can be a whey sensitivity as well. The result is that your immune system will respond to cheese, yogurt, etc. because the proteins are still present. Butter has only a little protein left, so you may not react to it, but I advise testing it so you can be sure.

4. Dairy products can cause constipation without being the result of an immune reaction.

Scientists have found that the peptides left from diary protein digestion can have a opioid activity. Like all opioids (hydrocodone, oxycodone, morphine, codeine), these dairy peptides can slow down the GI tract leading to constipation. This is thought to only occur in those who are especially sensitive to opioid activity.

If a person is sensitive to opioid activity and his/her digestive system is not great at breaking dairy proteins into individual amino acids, this can lead to a kind of addiction to dairy. If you’re one of those people who has to have cheese, consider that this could be the reason and see what happens to other symptoms you are experiencing when you remove all dairy products from your diet.

5. Dairy products often contain yeast, mold and/or estrogen which can feed Candida.

If you struggle with candidiasis, I encourage you to restrict or eliminate your dairy intake. It doesn’t necessarily have to be forever. You can do this for a period of time while observing symptoms and working with your healthcare practitioner to see if your candida population decreases.

But don’t I need dairy for calcium?

Um…. no. As I’ve said, there are no foods that have a monopoly on any given nutrient, and this holds true for calcium as well. In fact, many cultures don’t eat dairy at all and still manage to have strong bones, which you’d never believe was possible with all the ad campaigns for milk in the US! In fact, milk consumption may actually be weakening our bones as described so excellently by Dr. Michael Greger in this video.

Of course, our bones are made of calcium (and lots of other things), so we still need to get enough of it in our diets. However, if can’t effectively digest milk or it’s causing other problems in the body, then we aren’t benefiting from the calcium it contains.

Some great dairy-free sources of calcium are:

  • Beans (white, navy, pinto and black-eyed peas)
  • Canned salmon with bones
  • Sardines
  • Figs (dried or fresh)
  • Oranges
  • Greens (turnip, collards and kale)
  • Green peas
  • Broccoli
  • Butternut squash
  • Seaweed
  • Almonds
  • Sesame seeds
  • Chia seeds
  • Blackstrap molasses
  • Fortified non-dairy milks like almond milk and hemp seed milk



Bottom line: milk might be doing your body good, but only if you can digest the lactose, proteins and fats; don’t have an immune system that is triggered by the proteins and peptides; aren’t sensitive to the opioid effects; don’t struggle with candidiasis; and can handle the galactose it contains (as described in the video linked above).

If you want to give dairy-free a try, but aren’t sure how, contact me. Together we will create a personalized elimination protocol for you, so you learn how certain foods impact your body and you can eat foods that help you look and feel like the very best version of yourself.


— Ask Dr. Sears. Benefits of Goat Milk. In Feeding & Eating. Accessed on October 14, 2015.
— Department of Health and Human Services (US). Lactose Intolerance. In Conditions. May 2010. Accessed on October 14, 2015.
— Firger J. Adults Really Shouldn’t Drink Human Breast Milk. In Tech & Science. Newsweek. June 20, 2015. Accessed October, 14 2015.
— Gaby AR. Nutritional Medicine. Concord, NH: Fritz Perlberg; 2011.
— Greger M. Is Milk Good for Our Bones? March 16, 2015. Accessed February 8, 2017.
— Jenness R. Composition and characteristics of goat milk: review 1968− 1979. Journal of Dairy Science. 1980; 63(10):1605-1630.
— Kompan D, Komprej A. The effect of fatty acids in goat milk on health. INTECH. 2012. Open Access Publisher.
— Motala C, Fiocchi A. Cow’s Milk Allergy in Children. October 2011. Accessed October 15, 2015.
— Ross RP, Fitzgerald GF, Stanton C. Unraveling the digestion of milk protein. The American Journal of Clinical Nutrition. 2013; 97(6): 1161-1162.
— The George Mateljan Foundation. Cow’s milk. In The World’s Healthiest Foods. Accessed on October 14, 2015.

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