Should you eat dairy?

“Should you eat dairy?” is controversial to say the least.

The question is prevalent among the carnivore, paleo and keto communities (yet I believe relevant to anyone that eats dairy).

You may have heard that milk is healthy. It’s a great source of calcium that keeps your bones and teeth strong.

Or you may have heard that it’s unhealthy. And that full fat cream, butter, and cheeses make you fat. But these are all staples on a ketogenic diet – so what to do?

With the Carnivore Diet there is even more confusion. Dairy comes from an animal so it’s approved. But at the heart of the Carnivore Diet is eating in a way that is congruent with how humans are designed to eat, and dairy wouldn’t have been in the human diet until the Agricultural Revolution when humans first domesticated animals.

Within the last 7,000 years some humans adapted to eating dairy by developing a degree of lactase tolerance. As babies and adolescents we have a gene that encodes for the lactase enzyme which breaks down lactose (milk sugar). Through most of human history, this gene would “turn off” after infancy. Thus, all adult humans were naturally “lactose intolerant.” However, thanks to a mutation that kept this gene “on” (to some degree) throughout adulthood, lactase tolerance started to spread. (r)

So is it really a “natural” food?

I think it’s important to stop, rewind, and remember what dairy is meant for.

It’s meant to grow a baby mammal into a big mammal.

A calf into a cow.

In order to do this, it is loaded with energy – fat, carbs, and sugars. It is also loaded with vitamins, minerals and growth factors. This is not unlike human breast milk that is designed to supply a baby with what it needs to grow a lot and quickly.

Yet, cow milk and human milk aren’t the same.

3 Important Dairy Considerations

1. Milk Sugar – Lactose

As a white American with European ancestry, I use to think lactose intolerance was an uncommon genetic mutation. When, in fact, lactose intolerance is the normal, and those who are lactose tolerant, like myself, are the one’s who actually have the genetic mutation.

Lactose is the sugar in milk. In order to digest it, we need a special enzyme called lactase. As babies we have this enzyme. However, throughout human history the gene that controls lactase production “turns off” between the ages of 2 and 5. This corresponds with the weening of a baby off breast milk. So traditionally we lost the ability to produce lactase, and thus all humans (besides children) were lactose intolerant.

That was until about 7500 years ago.

With the domestication of animals, the easy energy from diary provided a large selective advantage from a survival standpoint. And a genetic mutation called the LP allele prevented the lactase gene from “turning off.” Adults with this mutation could now retain the ability to make lactase. Because of the selective advantage “lactase persistence” spread throughout Europe.

Yet, today, 2 out of 3 people in the world are still lactose intolerant, meaning they still lose the ability to produce lactase. If they consume lactose it goes through their GI tract and can’t get broken down. The lactose reaches the large intestines where bacteria ferment it and release lactic acid and gases. They often then feel bloated and suffer from pains and gases.

There is a spectrum of lactose tolerance. Many people still lose the complete ability to make any lactase at all and others can make enough to digest up to 90% or so of the lactose they eat. And then there are people in the middle.

2. Milk Protein – Casein

Besides the varying ability to digest lactose, milk proteins – casein and whey – can be problematic for many people. And those who have trouble with dairy, if it’s not from lactose intolerance, it is the milk proteins that give them problems.

Casein is a thick and sticky protein that takes digestive enzymes longer to break down. Because of this, it can be thought of as a “slow-release” protein.

Cow milk has a lot more casein than human milk, about 4 times as much. And it’s also different too. Cow’s have a form of casein called alpha S1 casein whereas human breast milk is beta casein. And it is this form of casein that is the most common cause of milk protein allergies.

Cows stomachs are different from human stomachs. And they have a special enzyme called rennet designed to break up big clumps of casein. We don’t have rennet. And many people have a hard time digesting large amount of casein.

3. Milk Protein – Whey

Whey is way easier to digest than casein. But, again, cow whey is different from human whey.

A problem with whey proteins in milk is that it causes insulin to rise similar to that of pure sugar. However, it doesn’t cause blood sugar to spike. This combination can destabilize blood glucose (hypoglycemia) and hormone levels that lead to cravings as well as mood swings and fatigue.

Whey also signals our body’s Growth Hormone (GH) to rise. Together with casein which signals IGF-1, you get a combination of hormone production that mimics what we see in puberty, fueling large amounts of growth.  This may be seen as a beneficial thing for a bodybuilder to supplement with after a workout, but perhaps not such a good thing to be stimulating on a regular basis throughout life…or for the general population in general.

“But don’t I need the calcium?”

Calcium absolutely has it’s necessary place in the human diet. However, its role in bone health isn’t as cut and dry as you might think.

Americans are a notable example.

We eat more dairy than almost any other country and have higher rates of osteoporosis. And there is a lack of evidence that dairy or calcium supplements strengthen bones or protests from osteoporosis. In fact, vitamin D seems more critical.

Addiction, Acne, and Absorption:

Besides the digestion of milk sugars and the potential adverse impact of milk proteins, dairy can play a role in being addictive, causing acne, and deficiency in iron.

• Milk peptides may have natural opioid properties which can make dairy seem addictive and sedating. Ever had that feeling that you can’t stop with one piece of cheese?
• A growth factor called betacellulin that can lead to acne through overproduction of sebum – the natural skin oils.
• Pediatricians advise parents not to feed their baby cow’s milk for the 1^st year because of the risk of developing an iron deficiency. The milk could interference with iron absorption and/or damage to GI tract.

Conclusions – “Should You Eat Dairy?”

Humans are designed to eat human breast milk as infants. Throughout history we were weaned off this which corresponded with the loss of the ability to digest lactose.

During the Agricultural Revolution, we first domesticated animals and began to incorporate dairy into the diet for the first time. At that time methods were developed to remove as much lactose as possible. Then through a genetic mutation, humans could retain the ability to digest lactose in varying degrees into adulthood. 2/3 of the world still can’t.

Cows milk, designed to grow a baby cow into a big cow, isn’t the same as human milk and certain incompatibilities, especially in milk proteins, can cause issues. The growth factors, while potentially beneficial in building muscle and fueling growth, may not be the best idea to stimulate day-in-and-day-out for long term health.

My guess is that those tolerant to lactose and without noticeable reactions to the milk proteins are fine to incorporate some dairy into the diet. It probably makes sense for bodybuilders, but less so for the general public.

Personally, after a hard workout or in a bind for food, I’ll have some whey protein. But I also know that the insulin rise without the corresponding blood glucose rise can, and often does, leave me hypoglycemic, feeling like death (sweaty, shaky, short-of-breath, that all-around panicky feeling).

I’ve found that most people feel far better when dairy is removed and/or limited.

My recommendation: What could it hurt to do a test, eliminate dairy for a month, and then try it back in and see for yourself.