12 min|Dr. Maya Kuczma
The Great Dairy Debate: Separating Myths from RealityWellness, Nutrition, Health, Gut Health
Dairy Has Great MarketingConsistent, targeted advertising and a prominent position on our food guide have led us to believe that milk is a health food. Humans are only species that continues to drink milk after weaning, but the dairy industry would have you think that milk, and milk products, are an essential part of a healthy diet. As of 2017, Health Canada has set a new precedent, banning meetings between lobbyists and bureaucrats who seek to influence the new food guide, and a new guide is in development that will recommend a more plant-based diet while discouraging saturated fat intake, as found in dairy and meat products. However, memos from Agriculture and Agri-food Canada indicate an attempt to exert influence on the guide, emphasizing the need for altering the language around meat and dairy usage, in order to protect these industries.(1)
While removal of saturated fat is misguided nutritional advice, this controversy highlights the historical influence of government and industry in our federal food recommendations. When businessmen define what is helpful, and healthful, our food choices are guided by dollars, not science, and the milk industry has a lot of dollars behind it.
The Truth Is...
When we look at the science, we see another story entirely. A story that shows dairy intake connected to a variety of symptoms and health conditions, as well as a milk of today that is not what it used to be. Currently, dairy products often contain exogenous hormones, antibiotics, additives, sweeteners, colouring, as well as an inappropriate ratio of nutrients due to how conventional livestock is fed.
Additionally, as a highly allergenic food, dairy certainly cannot generally be considered a health food. In fact, it may be largely to blame for many of the health concerns we face today.
Dairy As An Allergen, Intolerance, and Sensitivity
Much of the marketing for dairy has focused on a central idea - ‘milk is good for everyone’. No matter the age, race, or ethnicity, celebrities, politicians, and athletes have been slogging milk to the masses via dairy advertisements. The message is clear: they’ve got milk, and you should too. But research is showing that this is not necessarily the case.
For many us of, more milk equals more problems, due to a variety of immune reactions that occur in response to milk and dairy products. Cow’s milk allergies occur in up to 5% of children and can be mediated by an immune compound known as IgE. An IgE-mediated reaction typically occurs immediately and can include wide-ranging symptoms such as a rash, itchy skin, swelling of the skin, coughing, difficulty breathing, sneezing, congestion, nausea, abdominal pain, vomiting, diarrhea, and anaphylaxis.(2) Skin-prick testing can be used to identify this response.
Non-IgE mediated cow’s milk allergy, also known as ‘dairy sensitivity’, is typically IgG-mediated.(3) It is suspected that this reaction can occur up to three days after exposure. Symptoms can vary greatly and may be systemic or isolated to the digestive tract. Common symptoms include diarrhea, gas, bloating, headaches, joint inflammation, and skin changes such as eczema.
This reaction can occur in response to a variety of compounds in dairy, such as lactose, the sugar present in dairy, or casein or whey, proteins found in dairy.Lactose intolerance is not mediated by the immune system, instead of occurring as a result of lack of lactase enzyme. Beyond the age of 5, many of us lose the ability to digest lactose due to a down-regulation of the genes that control lactose digestion.(4)
It is estimated that roughly 75% of the world is lactose intolerant.(5) Symptoms tend to be limited to a digestive reaction, including gas, bloating, diarrhea, and cramps, but can be quite volatile. However, if you have lactose intolerance and no sensitivity to the other components of dairy, you may find that you tolerate cream, butter, ghee, or goat’s and sheep’s milk products, as they are very low in lactose content.
Dairy Can Promote Inflammation
Conventionally raised livestock are fed a diet largely consisting of corn, soy, and grain. This is an unnatural diet that leads to a skewed ratio of omega 6 to omega 3 fatty acids. Conventional dairy contains a ratio of 5.7:1 of omega 6 to omega 3(6). A higher intake of omega 6, in comparison to omega 3, has been linked to increased rates of cardiovascular disease, obesity, non-alcoholic fatty liver disease (NAFLD), inflammatory bowel disease (IBD), and rheumatoid arthritis.(7)
Consumption of conventional dairy products, as well as conventional livestock and industrial seed oils, contribute to an imbalanced elevation of omega-6 fatty acids in our diet, leading to an increase in inflammation. This holds true regardless of whether you have an allergy, sensitivity, or intolerance to dairy.
Dairy May Be Addictive
When casein is digested, casomorphins are produced. These morphine-like protein fragments attach to opioid receptors (8). No, they won’t get you high, but they may make you feel good - and wanting more. A leading theory is that this reaction occurs to ensure babies breastfeed (9). Beta-casomorphin-7, or BCM-7, a specific casomorphin produced from A1 beta casein, is of greatest concern.
It is suspected that BCM-7 plays a role in a variety of diseases, most notably autism and schizophrenia. When rats were given BCM-7, they became restless, aggravated, and exhibited reduced social interaction.(10) Urine samples of autistic children showed elevated levels of BCM-7 when compared to children without autism.(11) BCM-7 is produced as a by-product of A1 casein, the casein present in much of the conventional dairy sold in North America; further research is investigating whether A1 casein-free milk has the same effect as milk containing A1 casein on children with ASD and ADHD.(12)
This may provide further insight in regards to the effect on casomorphins on the brain. However, many naturopathic and functional medicine doctors are already using dairy-free diets as part of integrated treatment plans for children with ASD and ADHD; the majority of current research indicates generally positive improvements in core and peripheral symptomatology.(13)
The Link Between Dairy, Leaky Gut, and Autoimmune Diseases
Casein is structurally very similar to gluten; because of this, it is suspected that casein may have similar damaging effects on the gut lining as gluten (14). The observation that gluten and casein intolerance tends to go hand-in-hand only bolsters this case. However, it is unclear whether casein causes damage to the gut lining, or if gluten-induced damage occurs first, setting the stage for our immune system to respond to casein.
Casein is one of the primary proteins in human breast milk, so it seems unlikely that a reaction to this protein would occur independently of damage to the gut lining. But if the gut is already ‘leaky’, the immune system is poised to respond components of dairy products such as whey, casein, and casomorphin, further worsening the increased intestinal permeability and inflammation within the gut. For example, it is suspected that A1 casein plays a role in the complex, and multifaceted, etiology of diabetes type I.(15)
These studies do not claim that dairy in itself is sufficient to trigger a pathological process. Rather, it is likely that dairy, in combination with genetic predisposition, gut microbiota, compromised gut lining integrity, stress, and other factors, together contribute to the development of autoimmune conditions.(16) In this sense, dairy can be considered detrimental to individuals already at risk of developing an autoimmune condition such as those with a genetic predisposition and poor gut health.
Dairy’s Link to Cancer
Cow’s milk is a potent fuel for cows; it can turn a baby cow into a full-sized adult cow. To ensure this process, it is chock full of hormones, and can be considered anabolic (growth promoting). This is great news for a baby cow, but it may not be ideal for humans. Increased levels of estrogen metabolites have been associated with cancers of the reproductive system and are present in high levels in dairy products. It is suspected that consumption of dairy products high in estrogen metabolites may be a contributor to cancer pathogenesis.(17)
These metabolites appear to be most dangerous when separated from fat, as skim milk consumption has been linked to certain cancers such as prostate.(18) However, to further complicate the picture, milk consumption appears to be protective against colorectal cancer.(19) IGF-1, a protein, has been associated with wide variety of diseases including prostate cancer and chronic kidney disease, as well as all-cause mortality.(20-22)
Current evidence suggests that milk consumption increases IGF-1 levels.(23) Conventional milk consumption also contributes to insulin/IGF-1 signaling, a pathway linked to acne, diabetes, and cancer; however, it is unclear if dairy consumption alone triggers this pathway, or if it contributes to this pathway only within the context of diet rich in high glycemic carbohydrates typical of a Western diet.(24)
You Don’t Need Dairy For Strong Bones
If we believed everything we were told about dairy, we would expect countries with the greatest dairy consumption to have the lowest rates of fractures - a measure of good bone health. However, studies have shown that countries with the lowest rates of milk consumption also have the lowest rates of fractures.(25) In another study, high intake of milk was linked to a higher risk of fractures and mortality, particularly in women.(26)
Additionally, in a meta-analysis, no link between milk consumption and fracture risk was discovered.(27) Dairy products have been marketed as a healthy and essential source of calcium that people of all ages should be consuming. In fact, much of dairy advertising would have you believe that dairy is one of the only sources of calcium. However, there are many other sources of calcium including spinach, broccoli, almonds, sesame seeds, canned sardines and salmon (with bones), collard greens, boy chop, and blackstrap molasses.(28)
Additional, research indicates that bone density is not simply due to calcium intake. It is influenced by genetics, activity, vitamin D, in addition to a complex exchange between digestion and absorption of calcium and other minerals such as K2, blood sugar levels, and a loss of minerals through the intake of certain substances such as cola.(29-31)
But what about grass-fed? Or Fermented? Raw?
With all of these considerations, it’s no wonder there is considerable confusion regarding dairy consumption. Even amongst the ‘Paleo’ crowd, there is disagreement as to whether dairy should be consumed, with certain authors and researchers supporting the use of high-quality dairy, while others recommend complete avoidance.
Unfortunately, there is no simple answer as to whether you ‘should’ or ‘should not’ consume dairy. In short, it depends.The long answer depends on your health, your goals, and the quality of dairy you have access to. Much of the research discussed here was completed using conventional dairy. Very little research has been completed investigating the effects of grass-fed dairy, grass-fed raw dairy, or grass-fed fermented dairy products, in comparison to conventional. Although we need much more research, there are general guidelines we can keep in mind when it comes to dairy.
If you react to dairy, it is best to avoid it completely
This may seem obvious, but it bears repeating. If you notice a reaction to dairy, immediately or in the days following consumption, it is best to avoid it completely. If you suffer from allergies, asthma, eczema, acne, an autoimmune condition, obesity, or literally any other symptom, you may benefit from a trial elimination of dairy.
Remove it from your diet for 30 days and see if you notice any improvement. But take care - a true elimination involves eliminating all dairy products, including milk, cream, sour cream, cheese, yogurt, ice cream, butter, and so on. You cannot test your response to elimination if you continue to consume any dairy products.
But what about if you tolerate dairy well, do not suffer from a health condition, and would like to continue to consume dairy? The verdict is still out as to how much dairy may be too much, but there are a few rules of thumb to consider:
1. Choose Organic Dairy Products
In Canada, it is illegal to treat dairy cows with synthetic hormones and if they have to be treated with antibiotics, they are removed from the milk line until the course of antibiotics is completed.(32) In particular, BC standards are some of the strictest in the world regarding dairy quality.(33)
When purchasing dairy products, look for organic products from Canada, preferably BC, or choose organic dairy from other countries that are labelled ‘antibiotic and hormone free’, or products from New Zealand and Ireland, where the rates of antibiotic use are considerably lower than many other areas globally.(34,35)
2. Choose Grass-fed Dairy Products
They contain a more favourable ratio of omega 3 to 6, as well as elevated precursors for vitamin A and E, and CLA, a fatty-acid beneficial for heart health and body composition.(36)
3. Choose Full-fat Dairy Products
Low-fat contains higher levels of sugar and estrogen metabolites.(18) Additionally, trans-palmitoleic acid is only present in the fat of milk; this compound is believed to be a contributing factor in the health benefits associated with milk intake.(37)
4. Choose Unsweetened, Unprocessed Dairy Products
Avoid products that contain additives such as sugar, artificial colours, or artificial flavours.
5. Choose Fermented Dairy Products
Products like kefir and yogurt contain naturally occurring probiotics. Keep consumption to a minimum, eating small amounts of dairy products a handful of times per week. Whenever possible, rotate in sheep and goat’s milk products as they contain less A1 casein, less lactose, have higher medium chain triglyceride and vitamin A levels, and may not be allergenic even for those who are reactive to cow’s milk products.(38)
Many traditional groups have thrived with the inclusion of dairy; however, these groups tend to consume raw, fermented dairy that was very different from the conventional dairy available to us today. Fermentation lowers lactose content, making dairy products easier to digest, particularly for those who struggle to digest lactose. Pasteurization of milk depletes the nutritional content; raw milk also tends to be easier to digest and has been linked to lower rates of asthma and allergies later in life.(39,40)
For these reasons, raw, fermented, grass-fed, organic (phew, what a mouthful!) dairy may be best. However, raw milk is currently illegal in Canada. You may be able to find raw cheese, but for other dairy products, pasteurized fermented grass-fed organic and antibiotic-free, as well as organic and fermented goat and sheep’s products are your best bet.If in doubt? Take it out. Take a break and see how you feel. Your individual response to the food you eat, immediately and over time, is the best indicator of whether it is good for you.