Milk is a generally inexpensive, nutritious, and hydrating. It’s also an indispensable part of many people’s diets. Here in the United States, for example, most school children are served milk at lunchtime, and for many adults, it’s the fourth most common beverage after water, coffee, and soft drinks. We’ve all been told that milk is rich in calcium and protein, so it’s little wonder that so many people aim to include it in their daily diets.
That said, it’s not uncommon to also hear people say that drinking milk makes them sick to their stomachs—literally. In fact, many people claim that their health only improved after they cut milk from their lives. And it’s not just an improvement in digestion that people have noticed; many say that their acne, sinus allergies, chronic fatigue, brain fog, and general inflammation were vastly improved after saying “no” to milk.
I’m one of those people. After experiencing frequent gastro upset, fatigue, and a host of other unexplained issues, I decided to study molecular nutrition. What I learned about the common side effects and health issues associated with regular cow’s milk consumption inspired me to reduce my own consumption—and what followed can only be described as a change in my physical condition for the better. Below, a look at all the reasons I decided to give up milk, and what happened once I quit.
The impact of casein on the intestines
Casein is the main ingredient in milk—it accounts for about 80%. Though casein is a type of protein that contains a very large number of amino acids, it has also been linked to intestinal inflammation. Casein is actually now thought to be one of the causes of milk intolerance or dairy sensitivity.
There are several types of casein. Type A1 casein, which is found in many types of milk—especially in the milk from cows that originated in northern Europe, like Holsteins—is particularly prone to causing inflammation of the digestive tract, as it’s difficult for humans to digest. This undigested casein ferments in the intestines, producing gases and inflammatory substances that irritate the intestines.
On the other hand, A2 casein—which is mainly found in Guernsey, Jersey, and other cow breeds that originated in the Channel Islands and southern France—is considered relatively easy to digest and may cause fewer symptoms in people who are more likely to react to A1 casein.
Unless labeled “A2,” most regular milk contains both types of casein, meaning most milk can be difficult for a lot of people to digest. “Consumption of milk containing A1 beta-casein was associated with increased gastrointestinal inflammation, worsening of post-dairy digestive discomfort symptoms, delayed transit, and decreased cognitive processing speed and accuracy,” one study that looked at the effects of casein on the gut and brain reports.
Lactose intolerance
Lactose is a sugar found in dairy products. To break it down efficiently, our bodies use the enzyme lactase. However, the body’s ability to produce its own lactase often declines with age, making lactose difficult to digest—especially as we get older.
The inability to digest lactose is called lactose intolerance, and according to the National Institutes of Health (NIH), approximately 65% of the world’s population experiences some degree of lactose intolerance. In other words, most people are actually lactose intolerant.
What happens if you can’t digest lactose? Well, it ferments in the intestines and produces gas, causing abdominal pain, bloating, and more. “Lactose intolerance is a clinical syndrome characterized by gastrointestinal symptoms, such as bloating, abdominal pain, flatulence, nausea, borborygmi [intestinal rumbling], and diarrhea following the ingestion of lactose-containing food,” the National Library of Medicine confirms.
Antagonistic minerals
Milk is well-known as a source of calcium, but from a nutritional standpoint, the balance of magnesium shouldn’t be overlooked. Calcium and magnesium are called “antagonistic minerals,” meaning they compete for absorption. The ideal ratio of calcium to magnesium is 2:1, but milk is calcium-dominant at about 10:1 and up to 12:1. As a result, it can contribute to magnesium deficiency.
Incidentally, calcium causes muscle contraction, while magnesium has the opposite effect of relaxing muscles. Excess calcium without a balance of magnesium can cause stiff shoulders, back pain, and muscle cramps.
Antibiotics and hormones
Antibiotics and hormones are administered to cows in order to promote growth and prevent infections—but they can cause a residual problem for some milk consumers. “Significant portions of antibiotics are released through milk of dairy animals unaltered and exert serious harmful effects on human health,” one scientific review that looked at antibiotic residues in milk states.
Residual antibiotics can not only build antibiotic resistance, but they can destroy the balance of intestinal bacteria and worsen an inflammatory condition of the intestines called leaky gut. Additionally, “residues of antibiotics possess potential carcinogenic impacts by interacting with cellular elements, such as DNA and RNA,” the aformentioned review finds.
What happened after I cut back on cow’s milk
Though I still like the taste of milk, I no longer drink it on a daily basis—and as a result, I’ve noticed a dramatic improvement in my physical condition. The biggest impact? Less frequent stomach upset and reduced allergies, including hay fever. My chronic fatigue and brain fog have also improved, and my body no longer feels as generally inflamed.
I’ve replaced most of the milk I was consuming with non-dairy, plant-based alternatives—though of course, I’ll still occasionally indulge in milk products. It’s just no longer a daily occurrence. Instead, I think of milk in the same way I do certain other foods, like chocolate cake, potato chips, and alcohol—as a “treat.” My gut, brain, and body are grateful for the change.
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