Why is dairy problematic for most people?
When eating low carb, one may be confused about whether or not dairy should be included in a while foods based low carb diet. Its not surprising because there is a lot of mixed opinions in the low carb word about including dairy in a diet. Here are the compelling reasons why you should be cautions, and even consider not including dairy in your whole foods based, low carb diet.
Milk Sugars – Lactose
Lactose intolerance is not a rare genetic mutation. In fact, it’s the opposite. Lactose intolerance is the normal, and those who are lactose tolerant (to some degree), are in the minority.
Lactose is the sugar in milk. And to digest it, we need a special enzyme called lactase.
As babies we have a gene that encodes for the lactase enzyme which breaks down lactose. However, throughout human history the gene that controls lactase production “turns off” between the ages of 2 and 5, corresponding with the weaning 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 survival advantage.
Thanks to a genetic mutation, the LP allele, the lactase gene remained “turned on.” So adults with this mutation could retain the ability to make lactase. Because of the selective advantage “lactase persistence” spread throughout Europe. (r)
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. (r)
There is a spectrum of lactose intolerance. Many people lose the complete ability to make any lactase while others can make enough to digest up to 90% of the lactose they eat. To find out if you are one of these people, there isnt any kind of medical test. We just highly recocmend that you do a dairy elimiation diet for 30 days and observe your symptoms. If you you notice a difference in your bowl health or even lose some weight or have reduced acne, skin rashes or allergies, therse are all signs that you are indeed lactose intolerant and should restrain from having dairy.
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 the lactose, it’s from the milk proteins.
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. During my bodybuilding days, I remember I would take casein protein powder at night, for a slow release protein source while I slept.
Cow milk has a lot more casein than human milk, about 4X times as much. And it’s different too. Cow’s have a form of casein called alpha S1 casein. And it is this form of S1 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 amounts of casein.
A1 vs A2 Dairy
There is another variant of casein that is important to know about and that is A1 vs A2 dairy – variants within the beta-casein family.
Modern “Western” cow breeds have a mutation with beta-casein (where the 67th amino acid is histidine instead of proline) and they are called A1 cows. The “old” breeds, including buffalo, sheep, and goats, are A2. And most bovine contains a blend of A1 and A2 in different amounts.
Some studies have linked adverse health effects with A1 dairy. It’s thought that this is due to the digestion of A1 which produces a potentially damaging peptide called beta-casomorphin-7 (BCM-7) which can affect receptors in the nervous, endocrine, and immune systems. Further, there’s a good amount of anecdotal evidence from people who can’t consume A1 dairy but do just fine with A2. (r, r, r)
Milk Protein – Whey
Whey is way easier to digest than casein.
But a problem with whey proteins in milk is that it causes insulin to rise similar to that of sugar. And it 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 response for a bodybuilder, but perhaps not such a good thing to be stimulating on a regular basis throughout life…or for the general population that isn’t working out on a regular basis.
For people with body composition goals as a top priority, I do think that the strategic use of whey protein can help build muscle (for the right person, at the right time – i.e. well-trained, insulin sensitive, as a means of dietary progression, post workout, etc.) as well as help prevent muscle loss during a fat loss, caloric restricted period (when going from lean to super lean).
But I think this is the “exception” not the “rule,” and has to be weighed against the potential downfalls of stimulating anabolic growth factors as well as it’s overall effectiveness versus eating that protein as whole food meat. Overall, for the vast majority of people with body composition goals, replacing meat with whey protein powder is suboptimal.
Addiction, Acne, and Absorption
Besides the digestion of milk sugars and the potential adverse impact of milk proteins, dairy can be addictive, cause acne, and iron deficiency.
Milk peptides 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 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 1st year because of the risk of developing an iron deficiency. The milk could interference with iron absorption and/or damage to GI tract.
For all of these reasons above, we encourage everyone to do a 30-day dairy-free elimination diet and observe the results. If you have reduced symptoms of bloating, gas, GI issues, acne, weight loss, or allergies, this should be confirmation to you that dairy is problematic for you and should be consumed sparingly. If you can consume dairy, raw and A2 type dairy is best or unpasteurized. Also, keep in mind, even organic cows consume large amounts of corn and soy, both of which our bodies don’t do well with, so drinking soy and corn-fed cows milk or eating dairy from conventional dairy cows, may also be problematic due to the food that they have eaten and also the medications given to the cows to keep them healthy in their un-ideal living conditions. As with all animal foods, try and know your source as much as possible. Stressed, poorly fed, overmedicated cows are probably not producing dairy products or meat that you want to be consuming. Be picky about your sources and your health will thank you.
Thank you to kevinstock.io for the scientific content for this blog post