Understanding Dairy
Let’s talk about dairy.
One of my biggest pet peeves is when people try to make dairy a black and white issue. The internet is full of nutrition and medical professionals claiming that cow’s milk is either:
A disgusting abomination
OR
A vital life source that all children desperately need to survive
Not surprisingly, the truth lies somewhere in the middle. It helps to start by looking at the history of milk consumption.
The History of Milk
Humans as we know them have been around for about 300,000 years, yet the practice of drinking animal milk only began about 10,000 years ago. Knowing this, a modern parent might wonder, what did kids drink for the other 290,000 years!? Well, the answer is milk…human breast milk! (For clarity going forward, I will refer to human milk as breast milk and milk from any other mammal as animal milk). Babies were historically breastfed much longer, at least two or three years, as both a source of nourishment for the baby and as a way to delay the next pregnancy for the mother. In the event that a biological mother couldn’t or wouldn’t feed their baby, another lactating woman, commonly known as a wet nurse, would step in. Because humans were not yet keeping herds of animals, it never would have occurred to them to provide animal milk as an alternative.
Based on archaeological evidence, it appears that babies started receiving animal milk around three or four thousand years ago. One theory is that farming required women to produce more children, faster, to assist with work on the homestead. Stopping breastfeeding sooner restores fertility, but requires a supplemental feeding option – which is where animal milk comes in.
So, if you’re doing the math, adults have been drinking animal milk for 3% of human history, and young kids for 1%. I think it’s safe to say that the medical professionals claiming milk is an essential food for human growth and development are certainly wrong.
Now what about the group that says milk is an abomination? While 3% of human history is a relatively short blip, 10,000 years has to count for something. And that’s where it gets really interesting.
I think we need to do a deep dive into what milk looked like 10,000 years ago…or even 200 years ago.
Raw vs Pasteurized
First and foremost, up until the 1860’s all milk was raw milk. This is a really important point and likely one of the reasons that people starting drinking animal milk in the first place. As you probably know, one of the benefits of breastfeeding is that mom passes antibodies on to her baby through her breast milk. And since mom lives in the same environment as the baby, it’s likely that these are exactly the antibodies that baby needs at that very moment. When people drink the milk of locally raised animals, there is a similar benefit. But if that milk is pasteurized, the antibodies are destroyed. Pasteurization also reduces vitamin levels and denatures enzymes that make the milk easier to digest. So that’s a huge difference, and one that has only been around for 1% of the time humans have been drinking animal milk.
Lactose
Another thing worth talking about is lactose. Lactose is the main carbohydrate in all mammalian milk, including breast milk. Babies produce an enzyme called lactase which helps them digest lactose. Most mammals, including humans, stop producing this enzyme after childhood. Some humans did adapt over time to continue producing lactase into adulthood, but certainly not all. It is estimated that about 1/3 of the adult population today can properly digest lactose. For the rest, a cold glass of milk is likely to lead to gas, bloating and general discomfort. If we can’t digest the lactose in milk, the bacteria in our intestines will do it for us. And when bacteria feast on carbohydrates they produce a lot of gas. But here’s where it gets interesting. Before the advent of refrigeration, most milk consumed by humans was not fresh, but rather fermented. When milk is allowed to ferment, environmental bacteria will eat the lactose, essentially pre-digesting it for us. So while a glass of milk may be inappropriate for many, fermented dairy products like yogurt, kefir and cheese could be perfectly fine.
A1 vs A2 Beta Casein
Another part of milk’s makeup that needs to be discussed is casein. Casein is a family of protein molecules that account for the majority of the protein in mammalian milk. There are four subtypes of casein, and each subtype has a number of variants. The subtypes and variants vary from species to species, and even from animal to animal within a species. One subtype of interest is beta casein. There are 13 beta casein variants, but the two most common in cow’s milk are A1 and A2. A2 is thought to be the ancestral variant, whereas A1 came about due to a mutation in Holstein cows thousands of years ago. Because Holsteins are frequently bred with other species, the majority of milking cows today produce some combination of A1 and A2 beta casein. When A1 beta casein is digested, a molecule called betacasomorphin-7 is formed (BCM-7). BCM-7 is an opioid peptide that is loosely correlated with a number of health issues. While more research is needed, there is considerable observational evidence that heavily A1 milk causes more digestive upset than predominantly A2 milk. Other proposed consequences of A1 beta casein consumption include autoimmune disorders such as type 1 diabetes, heart disease, sudden infant death syndrome and autism. However, current evidence supporting these claims is very limited.
So what’s the verdict?
The holy grail of animal milk food would meet all of these criteria:
Raw milk…
from a cow bred to produce mostly A2 beta casein (or a non-cow mammal, as most other mammals such as goats and sheep produce little to no A1 beta casein)…
that was raised on pasture, allowed to graze freely on organic land…
and then fermented into yogurt, kefir or cheese.
The reality is, unless you have a homestead and make all of your dairy products from scratch, it’s pretty darn hard to meet all of these criteria all of the time. But as I like to say, don’t make the perfect the enemy of the good. If you enjoy dairy products, make the changes that you can. Perhaps you could…
Switch to organic dairy
Look for grass fed brands or brands that produce A2 milk
Choose goat milk or sheep milk products
Find a local farmer that sells raw milk
Lean more heavily on fermented options instead of fresh milk
Or maybe you just want to cut back on milk altogether
This is not an overnight change. I’ve been working to improve my family’s dairy habits for the past 10 years, and I suspect I’ll still be working on it 10 years from now!