Heather Bray, RD
*Disclaimer: the views and opinions of this article are based on the best available evidence and my professional opinion as a Registered Dietitian. This article is not meant to act as a substitute for medical or medical nutrition advice. For medical or medical nutrition advice that is designed for your individual needs, please consult your doctor or Registered Dietitian.
Dairy is a controversial topic in the world of nutrition. What I’ve observed is that some people will avoid dairy entirely because they heard that it is inflammatory. So, I’ve taken a look into the research to see what it has to say about dairy and its connections with inflammation.
Unfortunately many alternative medicine practitioners and social media “influencers” are spreading the message that dairy is inflammatory. What a big claim!
The word “inflammation” sounds serious so it makes sense that people are quick to make changes to their diet because of it. In my experience, I’ve seen this misinformation cause confusion and at the worst, harm, especially for those who rely on dairy products to meet their protein, calorie and calcium needs (e.g. elderly folks and children).
There are also some people who are choosing to avoid dairy because the concept of consuming dairy products seems “wrong” or “unnatural”. You may have heard people say “cow’s milk is for baby cows”. This post is not intended to address ethics or dive deep into farming practices. If you feel strongly about this then by all means make the switch to non-dairy alternatives.
A quick note on the “natural vs. unnatural-ness” of humans consuming dairy. When we think of our physiology, we have evolved to be able to break down dairy products thanks to an enzyme called lactase. In fact, dairy has been a part of the human diet for millennia. Some estimate the origins of human dairy consumption dates back to over 6000 years.
Ever heard of lactose intolerance?
Well this condition is when people do not produce (or do not produce enough of) the enzyme lactase that breaks down lactose (the sugar that is naturally present in dairy products). In fact, it’s estimated that 68% of people have some level of lactose intolerance [1].
That’s a lot! Luckily if this is you, there are a lot of products available on the market as an alternative.
Additionally, the milk proteins whey and casein have been shown to be readily absorbed by human muscles and have long been promoted as superior “post-workout proteins” (more on this another time).
So if we’re thinking about what’s natural or not, from a physiological standpoint, humans have evolved to be able to break down, absorb and utilize dairy products and have been doing so for a very long time (some more effectively than others as indicated above).
Some dairy products can offer many benefits such as micronutrients calcium, B12 and vitamin D, and other nutrients such as probiotics and protein.
Have you ever noticed how on one end of the internet you hear “dairy is inflammatory and should be avoided” yet on the other everyone’s eating cottage cheese and Greek yogurt with whey protein added to meet their protein goals? Or are consuming fermented dairy products like kefir and Greek yogurt for their probiotic gut health benefits?
Are some dairy products “okay” and others aren't?
Do some dairy products cause more inflammation than others?
Why has dairy become so confusing and controversial?
Again, if the concept of consuming dairy products feels weird to you or you have other ethical thoughts and feelings around our dairy farming practices, then I 100% support your decision in avoiding this. As a dietitian my aim is to help you make informed decisions.
First, we need to take a step back and understand what inflammation is.
What is Inflammation?
Inflammation is not always a bad thing. We need inflammation to keep us healthy. There are many different inflammatory processes in the human body. The type of inflammation that can be harmful is called chronic or systemic inflammation. Chronic means that it’s something reoccuring and/or lasts a long time so think arthritis, any kind of infection, chronic obstructive pulmonary disease, cancer, psoriasis, Chron’s/Colitis (Irritable Bowel Disease).
Chronic inflammation is also negatively linked with many health conditions such as cardiovascular disease, diabetes, liver diseases, chronic pain, cognitive decline, mental health conditions etc. Knowing this, it’s understandable to assume inflammation is bad so add a click bait title on social media and suddenly the narrative becomes: “inflammation = bad and must be avoided at all costs”.
The other type of inflammation is called acute (or short tem) inflammation. Acute inflammation is the type that occurs when you are sick, have an infection or injury or even after you exercise - yep that’s right, exercise causes low-grade inflammation [2] and without this response we wouldn’t be able to build muscle and get stronger [3].
It is also worth noting that inflammation is a normal part of digesting food. This is called “postprandial inflammation” which is a normal response. This is controlled by both pro- and anti-inflammatory effects of hormones excreted as a normal part of digestion [4]. However, some foods that we eat, and when we eat them often and in excess have been shown to produce chronic, low-grade inflammation such as the overconsumption of highly processed food (notice how I’m emphasizing quantity and type of processed food here).
A quick note: just because you experience bloating, gas, and other digestive discomfort, does not automatically mean that your gut is “inflamed” (although it may very well feel this way).
Understanding Dairy
Besides being a great source of micronutrients such as calcium, riboflavin, B12 and Vitamin D, dairy has a few other components to understand.
Dairy Proteins
The proteins present in dairy products are called whey and casein. For those with dairy allergies - they may have an allergic reaction to one or both of these proteins. You may have heard that casein is poorly absorbed, which often accompanies the argument that “dairy is unnatural to consume”. This is why you see “whey protein” powders and supplements marketed towards those who exercise, because the body absorbs whey quickly and readily.
However, just because the body takes longer to absorb and process casein doesn’t mean that this is a bad thing. In fact, it’s often discussed as an important protein in post-workout muscle recovery [5].
“Antibiotics” / “Hormones”
Due to our industrial farming practices, many people have concerns about the use of antibiotics and hormones to increase dairy cow’s milk supply. In Canada, it’s against the law for farmers to use antibiotics on cows that are producing milk - more on this process here. The Canadian Food Inspection Agency is diligent in monitoring and testing dairy milk for presence of antibiotics and hormones. In Canada, dairy farmers do not use antibiotics or growth hormones on dairy cows producing milk.
In fact, Canadian dairy has some of the highest standards of farming practices and safety testing in the world. There are, however, dairy products sold in Canada that come from the U.S. who’s testing and laws are not the same as Canada’s. It’s a good idea to look out for dairy products that are 100% produced in Canada when buying dairy products. Most of the big name dairy products such as: Liberte, Siggis, Oikos, Naturel and Fairlife all use Canadian dairy.
Mucus Production
Some people claim that consuming dairy makes them produce more mucus (especially when a cold comes on or with seasonal allergies). The evidence to describe the pathophysiology of this phenomenon is not clear, in other words, we don’t quite know why this happens to some individuals [6].
I’ve heard this claim countless times from people, and that my friends, is called anecdotal evidence. If you are someone who experiences excess mucus production by consuming dairy products (especially when you’re fighting off a cold) I think it’s fair to say that it makes sense to decrease your dairy consumption during this time.
This does not mean that everyone who consumes dairy products will have excess mucus production [7].
Pasteurization
There are some claims that the process of pasteurization “kills all the good nutrients” in dairy products. This simply is not true. While there are some nutrients that are denatured and decreased by heat such as riboflavin, not all nutrients are lost during this important food safety practice. Take protein for example, this nutrient is not sensitive to temperature and the pasteurization process therefore does not impact the level of protein in milk [8].
Pasteurization is a process where low levels of heat are applied to dairy products to kill off potential harmful bacteria - this is a life saving standard practice in dairy production and is especially important for those who are immunocompromised (e.g. pregnant people and elderly). This is because unpasteurized dairy products can carry salmonella and listeria. Which may only cause a mild to moderate sickness in some individuals but can be life threatening in others.
Dairy has long been recommended as part of a healthy diet because it provides micronutrients such as: calcium, riboflavin, B12 and Vitamin D.
Calcium specifically, not only helps with bone formation and maintenance but can also help with regulating blood pressure, kidney stone prevention and serum uric acid reduction [9]. Without dairy products and supplements, it can be very challenging to meet one’s calcium needs especially if the person is under 18 or over the age of 50.
What Does Science Say?
As always, there is mixed evidence, luckily for us this topic has been studied a lot!
A 2019 Systematic review of randomized clinical trials (RCTs) looked at 16 studies on the effects of dairy on inflammation [10]. The studies looked at individuals who would be considered otherwise “healthy”, those who fit into the “overweight” and “obese” criteria and those with metabolic syndrome and type 2 diabetes (BIG air quotes here because BMI is a very poor metric and should not be used to evaluate health status).
The outcomes measured in this study were lab values traditionally used to measure inflammation such as c reactive protein (CRP), interleukins, cytokines and other such as expression of pro-inflammatory genes. The review concluded that inflammation was not observed in individuals from all categories. They also mention that long-term dairy consumption may have an anti-inflammatory effect.
A 2014 RCT from McGill University published in the Journal of Nutrition, looked at how two different diet types affected inflammatory markers. One that included dairy, the other without. The authors concluded that in their short term trial, there was no effect on inflammatory markers in participants who consumed dairy [11].
Another 2022 randomized control trial with 289 participants found that people who were provided with fortified dairy products (specifically those high in Vitamin D) were found to have lower levels of serum inflammatory markers that those without. Of note, one hypothesis of this study was that Vitamin D deficiency can be a contributing factor to systemic inflammation. Regardless, the authors concluded that consumption of fortified dairy products may be helpful in reducing levels of inflammation [12].
Finally, a 2021 Systemic Review published in the Journal of the American College of Nutrition looked at 28 (RCT’s) which investigated the relationship between dairy products and inflammation. The authors concluded that of the reviewed literature, the consumption of dairy products and proteins had neutral and even a slight beneficial effect on inflammatory biomarkers [13].
All of these studies mention the need for more research, however, they all seem to lead to a similar consensus that dairy consumption does not cause inflammation in humans.
So, Should I Eliminate Dairy?
The answer is as most RD answers are, it depends. What it depends on is your personal experience, health history, preferences and accessibility (both financial accessibility and what’s available at your local grocer). Here are a few things to consider:
Lactose Intolerance
If you have some level of lactose intolerance, you may think that you need to eliminate dairy. Consider trying lactose free products first to see if you tolerate these well. There are also enzymes you can take (Lactaid) that can help you break down lactose in dairy products. It’s also worth noting that the amount of lactose is not always the same in all dairy products, for example, cheese and yogurt tend to be tolerated by those with minor lactose intolerance whereas cream and milk are not as well tolerated. This is because the amount of lactose that’s being consumed can often make the difference. This is something you will have to figure out based on your dairy consumption and symptom severity.
Dairy & Lactose Sensitivity
Some people, such as those with IBS or EOE (eosinophilic esophagitis), are highly sensitive to dairy (especially lactose). For those who have identified dairy as a trigger food, it makes sense to decrease it or find low-lactose options or use plant-based alternatives.
*note: a IgG food sensitivity test is not a diagnostic test nor will this provide you with accurate information as to weather or not you are sensitive to dairy products
Milk Protein Allergy
If you have a milk protein allergy (to whey or casein), you should definitely avoid dairy. If you’re not sure if you have a milk protein allergy, talk to your doctor and ask to be referred to an allergist to have this tested.
Your preferences
If you simply don’t enjoy the taste of milk, think that it’s “weird” or just overall don’t want to consume dairy products - no problem! Just make sure that you’re aware that meeting your calcium needs will be harder, though not impossible.
If you’re curious about meeting your calcium needs, check out the Calcium Calculator by Osteoporosis Canada
Bottom Line
Dairy isn’t likely causing any type of inflammation in your body. In fact, dairy may actually have some anti-inflammatory effects. Dairy foods to choose most often include: plain Greek yogurt, cottage cheese, Kefir, and milk.
Resources
References:
U.S. Department of Health and Human Services. (n.d.). Definition & facts for lactose intolerance - niddk. National Institute of Diabetes and Digestive and Kidney Diseases. Website
Cerqueira É, Marinho DA, Neiva HP, Lourenço O. Inflammatory Effects of High and Moderate Intensity Exercise-A Systematic Review. Front Physiol. 2020 Jan 9;10:1550. doi: 10.3389/fphys.2019.01550. PMID: 31992987; PMCID: PMC6962351.
Peake JM, Neubauer O, Della Gatta PA, Nosaka K. Muscle damage and inflammation during recovery from exercise. J Appl Physiol (1985). 2017 Mar 1;122(3):559-570. doi: 10.1152/japplphysiol.00971.2016. Epub 2016 Dec 29. PMID: 28035017.
Meessen ECE, Warmbrunn MV, Nieuwdorp M, Soeters MR. Human Postprandial Nutrient Metabolism and Low-Grade Inflammation: A Narrative Review. Nutrients. 2019 Dec 7;11(12):3000. doi: 10.3390/nu11123000. PMID: 31817857; PMCID: PMC6950246.
Tipton KD, Elliott TA, Cree MG, Wolf SE, Sanford AP, Wolfe RR. Ingestion of casein and whey proteins result in muscle anabolism after resistance exercise. Med Sci Sports Exerc. 2004 Dec;36(12):2073-81. doi: 10.1249/01.mss.0000147582.99810.c5. PMID: 15570142.
Frosh A, Cruz C, Wellsted D, Stephens J. Effect of a dairy diet on nasopharyngeal mucus secretion. Laryngoscope. 2019 Jan;129(1):13-17. doi: 10.1002/lary.27287. Epub 2018 Sep 4. PMID: 30178886.
Koren Y, Armoni Domany K, Gut G, Hadanny A, Benor S, Tavor O, Sivan Y. Respiratory effects of acute milk consumption among asthmatic and non-asthmatic children: a randomized controlled study. BMC Pediatr. 2020 Sep 12;20(1):433. doi: 10.1186/s12887-020-02319-y. PMID: 32919454; PMCID: PMC7488715.
Raw Milk Misconceptions and the Dangers of Raw Milk Consumption. US FDA (2011) Website
Cândido FG, Alves RDM, Freitas DMO, Bittencourt JM, Rocha DMUP, Alfenas RCG. Urate-lowering effect of calcium supplementation: Analyses of a randomized controlled trial. Clin Nutr ESPEN. 2022 Jun;49:86-91. doi: 10.1016/j.clnesp.2022.02.121. Epub 2022 Mar 9. PMID: 35623880.
Ulven SM, Holven KB, Gil A, Rangel-Huerta OD. Milk and Dairy Product Consumption and Inflammatory Biomarkers: An Updated Systematic Review of Randomized Clinical Trials. Adv Nutr. 2019 May 1;10(suppl_2):S239-S250. doi: 10.1093/advances/nmy072. PMID: 31089732; PMCID: PMC6518147.
Labonté MÈ, Cyr A, Abdullah MM, Lépine MC, Vohl MC, Jones P, Couture P, Lamarche B. Dairy product consumption has no impact on biomarkers of inflammation among men and women with low-grade systemic inflammation. J Nutr. 2014 Nov;144(11):1760-7. doi: 10.3945/jn.114.200576. Epub 2014 Sep 3. PMID: 25332474.
Sharifan P, Rashidmayvan M, Khorasanchi Z, Darroudi S, Heidari A, Hoseinpoor F, Vatanparast H, Safarian M, Eslami S, Afshari A, Asadi Z, Ghazizadeh H, Bagherniya M, Khedmatgozar H, Ferns G, Rezaie M, Mobarhan MG. Efficacy of low-fat milk and yogurt fortified with vitamin D3 on systemic inflammation in adults with abdominal obesity. J Health Popul Nutr. 2022 Mar 2;41(1):8. doi: 10.1186/s41043-022-00283-0. PMID: 35236423; PMCID: PMC8889656.
Nieman KM, Anderson BD, Cifelli CJ. The Effects of Dairy Product and Dairy Protein Intake on Inflammation: A Systematic Review of the Literature. J Am Coll Nutr. 2021 Aug;40(6):571-582. doi: 10.1080/07315724.2020.1800532. Epub 2020 Sep 1. PMID: 32870744.