By this point, you've made some changes in your routine that you started Jan 1st. Some of the changes are extremely successful, but if you're one of the people that has not made a profound difference in their lifestyle/health whether it be for energy levels, weight loss/gain, chronic health condition status etc., you might be viewing other, more drastic options. One of the easiest and most commonly executed options to get quick results without much brain work is by conducting an elimination diet. One of the dietary interventions that I hear about is the elimination of dairy products because they make people bloated/sluggish and in following an elimination diet these negative feelings make like a Houdini Act and disappear. Could this be true? The logic is sound, but let's go through the science and find out if getting rid of dairy from your diet can change the way you're feeling on a day-to-day basis.
The dairy industry has become one of the largest sectors in the modern food industry, so how can milk/dairy products be bad for you? Historically, human beings have not been able to always digest dairy products. During infancy, babies have, in most cases, been able to consume milk products without an upset stomach, due to the production of an enzyme called Lactase. This enzyme is used to help break down lactose, the main sugar in dairy products. However, this enzyme production slowed as infants grew out of infancy, through their adolescents and would completely stop (or turn off) the production of the lactase enzyme. Over the centuries, three factors allowed humans to overcome limitations imposed by lactose intolerance: (i) mutations, which occurred in particular populations, most notably in the north European Celtic societies and African nomads, in which carriers of the lactose intolerance gene converted from being lactose intolerant to lactose tolerant; (ii) the ability to develop low-lactose products such as cheese and yoghurt; and (iii) colon microbiome adaptation, which allow lactose intolerant individuals to overcome its intolerance. While we may or may not be able to digest milk products, is dairy powerful enough to be the reason we put on the pounds? Is that little brown almond the next best alternative to consuming dairy products? As far as the lactase enzyme issue is concerned, if you do not produce the lactase enzyme it is wise to consider reducing dairy intake. The alternative option for those struggling with lactase enzyme production is to ingest oral lactase enzyme pills. This can help reduce any gastrointestinal discomfort caused by lactose consumption in individuals with lactose intolerance.
As far as regular consumers go, dairy is on this list of things that people think make them fat. When people want to lose weight, they LOVE to cut out dairy. In fact, cutting out dairy is a staple of some diets like paleo or Whole30.
Here's the problem, though. Not only does dairy NOT make you fat, but if you cut out dairy from your diet, you might be making fat loss harder, not easier. Take the most commonly consumed alternative to dairy milk: Almond milk. Almond milk is a very convenient product designed to share textural similarities to regular bovine milk, in that the colour is white, opaque and is smooth and thick. Given these textural similarities, how does almond milk stack up against bovine milk, nutritionally? As it compares to bovine milk, plant-based almond milk is similar in flavour and texture, has a low caloric density and can be substituted in a multitude of different balanced diets, whereby it has two fairly large pitfalls. The first is that people allergic to tree nuts/almonds would not be able to consume, and the second con is that in order to have similar protein intake from the two milk beverages, you would have to consume a far higher fat and caloric intake from almond milk (producers mix various gums, palm oil and canola oil along with sweeteners to match the texture to bovine milk). Therefore, when utlizing milk beverages for its protein intake bovine milk is a superior option, especially for those with normal absorption of milk products and normal lactase production.
It has been repeated across many forms of literature that protein-rich foods are known to induce satiety, increase secretion of gastrointestinal hormones, and increase diet-induced thermogenesis. This means that foods high in protein, such as dairy-based foods provide a heightened feeling of satiety, and provide a larger thermogenetic response to consumption and therefore burn more calories while maintaining consumer's satiety levels. This means that if utilized properly, dairy products can be used strategically when engaging in a caloric deficit or even during maintenance calories in athletes to prevent caloric over indulgences.
What does the literature say? Does dairy cause weight gain? In a study conducted at the University of Minnesota, low-fat dairy products did not promote weight gain, while high-fat dairy products did. Hmmm, could it be that the weight gain in this study was simply caused by excess calories and not the dairy? In another study, increased intake of dairy products did not affect body composition. In a third study, increased intake of dairy products did not impair weight loss. In a one-year study, increased intake of dairy products did not affect changes in fat mass. In a 6-month follow-up to this study, high dairy product intake predicted lower levels of fat mass. In a 9-month study, increased intake of dairy products did not affect weight maintenance, but the high dairy group exhibited evidence of greater fat oxidation. In a study on overweight police officers, dairy protein resulted in greater loss of fat mass, and greater gain in lean mass, compared to no dairy protein.
Plenty of evidence is present to suggest that dairy is not to blame for the fat mass gain in humans, but rather to speculate that fat mass gains are as a result of an increase in total caloric intake. That being said, the most superior form of evidence of whether dairy can impact body fat is by looking at the weight of the evidence across a large body of controlled trials. To do that, we need a meta-analysis, where scientists take a large body of studies and analyze them as a group to get an idea where the overall body of evidence points to. Fortunately, there was one such meta-analysis published in 2012. In this analysis, the authors found that dairy helped reduce body fat by an additional 1.11 kilograms over no dairy when people were restricting their calories.
When we look at a body composition it is proven beyond a reasonable doubt, that dairy is not to be blamed for an increase in body fat mass, in fact, it has been repeatedly proven that dairy can be used to promote muscle gain without added fat gain. That being said, are there any indications that suggest any effects of dairy on immune response or inflammation? After all, I'm sure the movie game-changers have convinced you that dairy and other animal products cause inflammation, and surely that must have an influence on immune response, right? A review was published outlining the current literature surrounding dairy product intake and inflammation. Overall, the IS (inflammatory score) of the entire data set composed of 78 study results, extracted from 52 human studies indicates that the consumption of dairy products is associated with anti-inflammatory properties in humans. Not only is the data set unable to prove the claims made in the GameChangers film, but it goes so far as to indicate that dairy products boost anti-inflammatory characteristics.
Furthermore, the existing epidemiological evidence suggests that the consumption of raw cow’s milk contributes to protection against allergies and asthma and respiratory tract infections. A 2018 review discussed potential mechanisms by which cow’s milk and its components may exert these immunological effects as it relates to the respiratory system. Bovine IgG can bind to bacterial and viral pathogens, enhance phagocytosis, and may neutralize pathogens. Other milk components like TGFβ promote epithelial barrier functioning by upregulation of TJ genes and might favour the differentiation of Tregs that can reduce inflammation locally. Finally, recent evidence shows an interplay between gut and lung. Researchers speculated the effect of milk components on the trafficking of lymphocytes from the intestine to the upper airways through modulation of homing receptors and microbiota. Further unravelling the impact of milk components on local responses in the respiratory tract, microbiota and immune trafficking is necessary to fully understand their effects on allergy, infection, and asthma.
To conclude, the current literature presented shows that while there are still gaps in research as it relates to the respiratory tract connection with the microbiota, there are several conclusions that can be drawn with regards to the consumption of dairy. Dairy intake has shown not only any correlation between added fat mass gain, but it can also be concluded that dairy positively influences the satiety of consumers, and to be an impressive tool in weight management. Assuming that there are no indications of allergies to dairy or any intolerances, dairy is a great source of protein-rich nutrition with anti-inflammatory properties and no sign of detrimental effects on the respiratory tract. It is with this information, that I use my professional judgement, to recommend that in a healthy individual dairy products can be great tools for increased protein consumption and that there is no reason why one should remove dairy from their diet, especially in the case of individuals looking to lose weight or change their body composition.