With autoimmune thyroid conditions such as Graves’ Disease and Hashimoto’s Thyroiditis, there is a lot of emphasis on avoiding gluten. And while I agree that people with these conditions should go on a gluten free trial, many natural healthcare professionals will also advise their patients to avoid dairy. This causes a great deal of confusion, as many people think of dairy as being healthy. Without question there are health benefits of certain types of dairy, but some forms of dairy can have a negative consequence on your health, which I will discuss in this post.
When I was growing up I drank plenty of cow’s milk. I also drank plenty of soda, fruit punch, and other unhealthy beverages as well. But of course the focus of this blog post is on dairy, and so let’s stick with this topic. Getting back to cow’s milk, many people perceive cow’s milk as being healthy. Although drinking cow’s milk is very healthy for baby cows, it’s not necessarily healthy for humans. Fortunately, more and more people are realizing this, and thus are substituting cow’s milk with almond milk or coconut milk. Unfortunately some people drink a lot of soy milk, which isn’t much better than cow’s milk, and is arguably even worse. But when it comes to cow’s milk, drinking this can cause a lot of health problems, and can potentially lead to conditions such as acne, obesity, type 2 diabetes, and even cancer. I will discuss the mechanism behind this shortly.
Why Is It Important To Avoid Drinking “Conventional” Cow’s Milk?
As I mentioned before, many people still think of cow’s milk as being healthy, and as a result they are drinking it on a regular basis. On the other hand, some people with thyroid and autoimmune thyroid conditions have been told to avoid dairy, and because of this they no longer drink any milk, and might avoid other forms of dairy such as yogurt, whey, and cheese. I’ll briefly talk about these other forms of dairy later on in this post, but let’s first answer the question “why is commercial cow’s milk bad for you?” There are a few different reasons for this:
Reason #1: The hormones. Most people realize that cow’s milk contains hormones. Cow’s milk contains estrogens and could stimulate the growth of hormone-sensitive tumors (1). I briefly mentioned soy milk earlier, and there is evidence that soy milk could increase the growth rate of breast cancer cells (1). Getting back to cow’s milk, many people are aware that growth hormones are given to dairy cows to increase the milk production. While it’s probably a good idea for everyone to avoid non-organic milk due to these hormones, it is especially important for children to avoid drinking cow’s milk. While drinking organic cow’s milk would be a healthier choice, it’s important to keep in mind that organic milk might not have growth hormones added, but this doesn’t mean it will be free of estrogens. Due to these and other factors I’m about to discuss, avoiding conventional cow’s milk altogether is probably best, whether or not it’s organic or non-organic.
Reason #2: The Pasteurization Process. The pasteurization process was developed by Louis Pasteur in 1864, and involves heating the milk to a specific temperature in order to kill harmful bacteria. When you think about pasteurization this might sound like a very good idea. The problem is that heating the milk decreases many of the nutrients, such as vitamin B1, B2, folate, B12, vitamin C, and vitamin E (2). In addition, the pasteurization process will modify the proteins of dairy, and can potentially lead to a greater increase in food allergies, although some argue that the opposite occurs, as by denaturing the proteins this might make someone less susceptible to a dairy allergy. Earlier I mentioned how organic milk will have estrogens from the cow. Some might wonder if the pasteurization process will inactivate these hormones, but organic and conventional dairy products do not have substantially different concentrations of estrogens (3).
Reason #3: The Homogenization Process. Why is commercial milk homogenized? The process of homogenization helps to give milk it’s white color and smooth texture, and also might help with the digestibility of milk (4). An excellent review article was written on homogenization and the potential link between cardiovascular disease, diabetes, and allergy (Click Here to read this article). Homogenization changes the physical structure of milk fat and because of this might alter the health properties of milk. If you read this review article you’ll see the evidence which shows the increased risk of cardiovascular disease and type 2 diabetes in those who drink homogenized milk. However, to be fair, most of these involve observational studies, and it’s difficult to use these to prove a direct correlation between milk consumption and these diseases.
For example, one of these studies show that the consumption of cheeses manufactured with non-homogenized milk is high in France where coronary mortality is low, whereas in Scandinavian countries homogenized milk consumption is high, and so is coronary mortality (5). But of course there might be other factors responsible for the difference in coronary mortality. In addition, as of writing this post there are no clinical studies which compare homogenized to non-homogenized dairy products. With regards to allergies to dairy, many people have claimed that they are unable to tolerate homogenized milk, but do fine when consuming non-homogenized milk.
Reason #4: The mTORC1 pathway. There is something called the mammalian TOR complex 1 (mTORC1) and it seems that this signaling pathway plays a big role in the development and progression of numerous conditions. This includes conditions such as acne (6) (7), as well as chronic conditions such as obesity (8) (9) (10), type 2 diabetes (10), and cancer (11) (12) (13).
But how can this signaling pathway lead to the development of these chronic conditions? Well, dairy proteins and meat stimulate insulin and insulin-like growth factor 1 signaling and provide high amounts of leucine, which causes mTORC1 activation (10). Something called kinase S6K1 is a downstream target of mTORC1, and this interaction leads to insulin resistance, which in turn increases the metabolic burden of B-cells (10). In addition, leucine-mediated mTORC1-S6K1-signaling plays an important role in adipogenesis, which in turn increases the risk of obesity-mediated insulin resistance (10). I realize that this is probably difficult to understand for many reading this, but the important point to understand is that activation of the mTORC1 pathway can lead to numerous health conditions, and leucine, which is an amino acid found in high amounts of dairy products, can activate the mTORC1 pathway.
Does this mean that drinking commercial milk will always lead to a condition such as obesity, type 2 diabetes, or cancer? Of course not. As I mentioned at the beginning of this blog post, I drank cow’s milk growing up on a daily basis, and I never developed insulin resistance. However, the same point can be made about other allergens as well. For example, some people do fine when eating gluten. On the other hand, many people don’t do well, and the health consequences of eating gluten could be severe when one is gluten sensitive. And of course gluten isn’t necessary to consume. The same can be said for pasteurized/homogenized cow’s milk. While some people do fine with this, others don’t do fine. And just as is the case with gluten, it’s unnecessary to drink cow’s milk.
Many people are aware of the glycemic index, and milk actually has a low glycemic index, which is a good thing. However, cow’s milk, along with other types of dairy, has a high insulin index, which means that it causes a high insulin response. I’m sure some people will wonder if it’s healthier to drink other types of milk. For example, how about drinking milk from a goat or sheep? There hasn’t been as much research on these types of milk, although it appears that the insulin index is similar to cow’s milk.
Another Problem With Cow’s Milk: Beta Casein A1
Cow’s milk consists of both casein and whey protein. Cow’s milk consists of approximately 80% casein. Although many people are lactose intolerant, some people are sensitive to casein. Although many people seem to have a “casein intolerance”, only a small percentage of people actually have a casein allergy, and will test positive for casein antibodies during IgE testing. However, in addition to milk, other dairy products include casein, such as yogurt and cheese.
There are different types of casein in dairy cows. The most common forms of beta-casein in dairy cattle breeds are A1 and A2. It is thought that beta-casein variant A1 yields the bioactive peptide beta-casomorphin-7 (BCM-7), which may play a role in the development of certain human diseases, such as diabetes mellitus and ischemic heart disease. There also might be a relationship of BCM-7 to sudden infant death syndrome (14). So just to clarify, BCM-7 can lead to the development of numerous chronic health conditions, and is found in beta-casein A1.
It’s also important to understand that some people react to beta-casein A1, but do perfectly fine when consuming beta-casein A2. The challenge is finding out where the dairy you purchase is coming from, and unfortunately most of the milk in the United States comes from “A1 cows”. I’ll talk about raw milk shortly, as this is definitely a better option than conventional milk. However, from what I understand, not all raw milk is made from “A2 cows”, which might explain why some people don’t do well when drinking raw milk. So what’s the best way to get milk which has beta-casein A2? You might need to go directly to the source, which means contacting some of the local farmers to find out whether they have “A1 cows” or “A2 cows”. I mentioned before how the milk from a goat or sheep probably has a high insulin index. However, they apparently don’t have BCM-7, which is probably why many people do better when drinking these types of milk.
Is It Okay To Drink Raw Milk?
There is no question that drinking raw milk is a healthier option when compared to commercialized milk. When it comes to drinking raw milk, one of the main concerns people have is the safety of it. Without question, there are risks with drinking raw milk. However, as I already mentioned in this blog post, there are also risks with drinking pasteurized milk. Chris Kresser does a great job of discussing the risks of drinking raw vs. pasteurized milk in an article entitled “Raw Milk Reality: Is Raw Milk Dangerous?“. For those not familiar with Chris, his articles are research-based, and if you’re concerned about drinking raw milk due to the possibility of becoming ill then you need to read his article.
Although there are health benefits of drinking raw milk, when I recommend for my patients to initially follow a natural treatment protocol I usually will advise them to avoid all dairy. In the future some people will be able to add dairy back into their diet, and when this is the case, raw dairy will be a great option for many of them. On the other hand, some people are better off avoiding all dairy on a permanent basis.
What About Other Types Of Dairy?
Most of this post focused on the risks associated with drinking cow’s milk. But is it okay to consume other types of dairy? As I just mentioned, initially I recommend for my patients to avoid all forms of dairy. This includes not only milk, but yogurt, cheese, kefir, and whey. The reason for this is because some people are sensitive to these other forms as well. However, I think that it’s fine for many people to eventually reintroduce other forms of dairy into their diet, as there definitely are health benefits to eating certain types of dairy, such as yogurt, kefir, and whey. But it does depend on the person, as some people might need to avoid certain forms of dairy for a prolonged period of time. Others might need to avoid dairy on a permanent basis. For example, if someone has a casein allergy then they will need to avoid not only milk on a continuous basis, but should also avoid yogurt, cheese, butter, and other dairy products which include casein.
Since butter is low in casein some will feel that it is fine to consume. This might be true, but if someone has a known casein allergy then I would still recommend for them to avoid it. Of course as I mentioned before, one also needs to consider the type of casein one is consuming, as some people will do fine consuming dairy from a goat or a sheep. It admittedly can be challenging at times to know exactly what a person should and shouldn’t eat, but when someone is trying to restore their health back to normal I would rather play it safe and have them avoid all type of dairy initially.
Some people are concerned about getting enough calcium if they are avoiding dairy. Although dairy is the primary source of calcium for many people, there are other foods which are high in calcium. Kale is high in calcium, and so you can eat steamed kale, and/or add it to a smoothie. Chinese cabbage is also an excellent source of calcium (15). Collard greens, broccoli, almonds, and blackstrap molasses can also provide a sufficient amount of calcium. So there are plenty of non-dairy sources of calcium.
In summary, there is a lot of controversy over whether dairy should be consumed in people with conditions such as Graves’ Disease and Hashimoto’s Thyroiditis. Since many people are sensitive to dairy I do recommend for all of my patients to initially avoid dairy. But this doesn’t mean that everyone should avoid dairy on a permanent basis. Raw dairy is definitely preferable to commercial dairy. However, there are different types of casein, and many people react to beta-casein A1, yet do fine when consuming dairy which has beta-casein A2. So if someone avoids dairy for a prolonged period of time and then reintroduces it back into their diet, they might want to consider raw dairy, and also do some research so they consume dairy which consists of beta-casein A2.