Why your tummy might say 'no' to cow's milk

From lactose to protein and exorphins: this is what cow's milk does to your body

Cow's milk. For some, a source of calcium, protein and comforting cappuccinos. For another, the cause of abdominal pain, skin complaints or fog in the head. Not everyone reacts the same to milk, and that's not crazy at all. In this blog, we'll take you through the world of lactose, milk proteins, exorphins and everything in between.

Note: I try to do as much research as possible so you don't have to and find everything gathered in one place. I am not a doctor and do not give medical advice, but try to help you from my own experiences.

What is actually in cow's milk?

Cow's milk is more than "milk from a carton." Most of it is water. It also contains lactose, the natural milk sugar that your small intestine normally uses the enzyme lactase to cut into two smaller sugars, glucose and galactose. Milk also contains milk proteins. Most of it is casein and a smaller portion is whey protein. There is also milk fat in small fat globules and you will find vitamins and minerals such as calcium, phosphorus, potassium, B2 and B12. All these components have their own function and can also trigger symptoms in some people.

• Water (approx. 87%)
  The basis of milk. Quite innocuous, but essential for structure.
• Lactose (approx. 4.8%)
  Milk sugar. This sugar consists of two smaller sugars: glucose and galactose. To digest these properly, you need the enzyme lactase.
• Proteins (approx. 3.3%)
  Subdivide into:
  • Casein (about 80% of milk proteins)
  • Whey Protein (about 20%), such as beta-lactoglobulin and alpha-lactalbumin
• Fats (approx. 3.7%)
  Milk fat occurs in small fat globules with a protective coating.
• Vitamins and minerals
  Consider calcium, phosphorus, potassium, vitamins B2, B12 and D. Important for health, but rarely a cause of symptoms.

All these substances have their own function and possible influence on the body. But in some people, things go wrong.

Lactose intolerance: when your body does not like milk sugar

At lactose intolerance do you make too little lactase. The lactose is then not completely broken down and slides through to your colon, where bacteria ferment with it. You feel this as a bloated belly, flatulence, cramps and sometimes diarrhea. You often notice this relatively quickly: usually within 30 to 120 minutes of eating or drinking something with lactose.

What can you do with this in everyday life? Many people benefit from lactose-free varieties of milk, yogurt, cream or ice cream. Others use an occasional lactase supplement with a dinner party or impromptu ice cream. Hard, longer-aged cheeses usually contain little lactose and are therefore often better tolerated. A handy overview can be found in Which cheeses contain high or low levels of lactose.

So what exactly is happening?

When your body lacks lactase, lactose digestion stalls. In plain language: the "cutting enzyme" is missing, preventing the sugars from passing through the intestinal wall. Step by step, it looks like this: the lactose enters your small intestine, but there is not enough lactase to break it down.

The undigested lactose moves to your large intestine, where intestinal bacteria work on it (fermentation). This produces gases and acids, which you notice as flatulence, cramps and sometimes diarrhea.

Common complaints

This is what it feels like in real life: after a creamy coffee or dessert, your belly can suddenly "fill up," your waistband can feel tighter and you may experience cramping or a sudden toilet visit. For some this is intense, for others subtle; how much you eat, how much lactase you still make and how sensitive your bowels are all play a role.

• Bloating: your belly feels full and tense, as if you have swallowed a balloon.
• Flatulence: you leave gas more often (sometimes loud, sometimes quiet, rarely odorless).
• Abdominal pain or cramping: sharp, nagging or pulling in the lower abdomen, often after eating.
• Diarrhea or thin stools: undigested lactose attracts water, which can make stools thin.

The severity varies from person to person. Some can tolerate a splash of milk in their coffee just fine, while others react to just one bite of yogurt.

What can you do about it?

Good news: you have options. Choose lactose-free dairy products As a daily basis, use lactase enzymes as a tool for occasions, or go for plant-based alternatives If you want to stay completely lactose-free. Slowly test what works for you and build up from there.

Cow's milk allergy and cow's milk intolerance

Cow milk allergy and cow milk intolerance are often confused, but they are really different.

Cow's milk allergy is a reaction of your immune system. Your body sees milk proteins as invaders and takes action. This can cause symptoms within minutes to hours. Sometimes mild (itching, eczema), sometimes severe (tightness in the chest or anaphylaxis).

Cow's milk intolerance is not an allergy and is not caused by an immune reaction. Rather, it is a sensitivity or digestive problem. Complaints usually appear later (hours or even the next day) and are often limited to the intestines, skin or energy levels.

Cow's milk allergy: when your immune system goes into action

Cow's milk allergy is different from lactose intolerance. Whereas lactose intolerance is about digesting milk sugar, cow milk allergy is about a defense reaction against the proteins in milk, usually casein or whey proteins. Your immune system sees those proteins as "dangerous" and springs into action.

This can quickly cause symptoms ranging from skin and gut to respiratory. If you are unsure about the distinction from intolerance, read: What is the difference between cow's milk allergy and cow's milk intolerance (https://noomooo.com/nl/verschil-koemelkallergie-koemelkintolerantie/)

Symptoms may include

An allergic reaction often comes on quickly, within minutes to a few hours of eating or drinking dairy products. You may develop an itchy rash or eczema, sometimes with red bumps or flakes. Swelling of lips or face also occurs, as does nausea or vomiting shortly after ingestion. The abdomen may hurt sharply or cramp, with or without diarrhea.

In more severe reactions, the airways come into play and tightness of the chest or wheezing occurs; in rare cases, an anaphylactic reaction may occur. Cow's milk allergy is most often seen in infants and young children, but adults can also develop or keep it.

Phenomena summarized

• Skin rash or eczema: itchy, red patches on the skin, sometimes with flakes or bumps.
• Swelling of lips or face: sudden swelling after eating or drinking milk products.
• Nausea or vomiting: shortly after ingesting milk, you get a giddy or nauseous feeling.
• Abdominal cramps: sharp pains, sometimes combined with diarrhea or vomiting.
• Shortness of breath or wheezing: especially for severe allergies, affecting the respiratory tract.
• Anaphylaxis (in severe cases): life-threatening allergic reaction, with drop in blood pressure and shortness of breath.

How do you recognize the difference with lactose intolerance?

With an allergy, reactions usually occur quickly and you often see skin and/or respiratory symptoms. With lactose intolerance, on the other hand, gas, cramps and diarrhea predominate due to problems digesting milk sugar, and these symptoms do not always come immediately. For cow's milk allergy, your doctor may do targeted testing, such as IgE testing or a prick test, to support the diagnosis.

What can you do?

The basis is strict avoidance of cow's milk protein. That means reading labels carefully and also watching for hidden sources in processed products. Infants may require a hypoallergenic diet; always discuss this with your doctor or dietitian. If you suspect allergy or experience a severe reaction, contact your doctor or (in acute situations) emergency care immediately. So:

• Complete elimination of cow's milk protein from your diet.
• Read labels carefully (also avoid hidden proteins).
• Possibly switch to hypoallergenic products (e.g., for babies).

Cow's milk intolerance: if you are sensitive to the proteins in milk

Cow milk intolerance is often confused with cow milk allergy, but there is an important difference. In cow's milk intolerance, the immune system does not play a direct role. So your body does not react allergically but hypersensitively to certain components in cow's milk, usually the proteins such as casein or whey proteins.

This form of intolerance is less easy to demonstrate with a test, because no antibodies are produced as with an allergy. Still, the symptoms can have quite an impact on your daily life.

What happens with cow's milk intolerance?

In short, you don't digest milk proteins optimally. This can irritate the intestinal wall and trigger a mild inflammatory reaction. You don't just see the result in your gut; skin and energy levels can also participate. The reaction is often delayed and builds up, so the link to dairy is not always immediately obvious.

• Your body does not digest the proteins in milk well.
• This can lead to (mild) inflammatory reactions in your intestines.
• This can cause intestinal problems, as well as skin or energy issues.
• The symptoms often appear gradually or with a delay, making it difficult to link them to cow's milk.

Common complaints

In practice, you notice this as a nagging or oppressive abdominal pain (often after meals with dairy), a bloated feeling as if your belly is "filling up," fluctuating stools from constipation to diarrhea, and a falling energy meter after eating. Some people also recognize headaches or migraines as triggers around dairy products, or a gloomier, flat feeling when the intestinal reaction lasts longer. So:

• Abdominal pain or cramps: a nagging or pressing sensation, especially after meals containing dairy products.
• Bloating: as if your belly suddenly "fills up" and your clothes are tighter.
• Alternating stools: sometimes constipation, sometimes diarrhea, often with no apparent cause.
• Fatigue: your energy sinks, especially after eating.
• Headache or migraine: in some people, dairy products can be a trigger.
• Gloomy mood: because your body is constantly responding at a low level, you may feel less mentally fit.

How do you know if cow's milk intolerance is your problem?

A "hard" test is usually lacking. In practice, a structured approach works best: a period completely without cow's milk to see if symptoms subside, followed by a controlled reintroduction. If you see a clear pattern during that reintroduction, it points toward cow's milk intolerance.

What can you do?

Start with a simple food diary to link portions and symptoms. Switch temporarily to dairy-free alternatives and evaluate how you feel. For additional guidance, guidance from a dietitian experienced in food sensitivities can help.

• Start an eating diary to recognize patterns.
• Switch temporarily to dairy-free alternatives.
• Consider guidance from a dietitian experienced in food sensitivities.

Although it sometimes feels like you have to "prove" that your complaints are real, here goes: your experience counts. If you find that you have more energy and less tummy upset without cow's milk, that's a valuable conclusion.

Exorphins: milk that affects your mood?

Sometimes it's not just about abdominal complaints. There is also a conversation about exorphins: small protein fragments (peptides) released during the digestion of casein. They resemble body substances like endorphins and can bind to the same receptors in the brain as opioids.

That sounds technical, but the idea is simple: in a subset of people, these bits of protein would play into how you feel and focus.

What could that do?

Think of these as possible signs that some people recognize in themselves. It varies greatly by person and intensity.

• Concentration problems: where before you could work for an hour, now you are distracted after a few minutes.
• Fog in your head (brain fog): as if a cloud hangs between you and your thoughts; simple tasks take more effort.
• Sleep problems: difficulty falling asleep, restless continued sleep or waking up as if you haven't slept.
• Irritability: A short fuse; small things can frustrate more quickly.
• Gloom: You feel flat or dejected more often for no apparent reason.
• Behavioral changes in children: quicker anger, difficulty with stimuli, difficulty concentrating or hyperactivity.

Has this been proven?

The short version: science hasn't figured it out yet. The idea that exorphins influence behavior and mood comes mostly from smaller studies and is more often examined in groups with autism or ADHD, for example. Results are variable and not unequivocal.

At the same time, some people report feeling subjectively better when they avoid casein (temporarily). So it remains a personal consideration.

What can you do?

If you want to explore without much fuss whether this plays out for you, keep it simple and structured.

• Try a casein-free period (say 4 weeks) and see if there is any difference.
• Observe purposefully: note mood, sleep and concentration in addition to your meals.
• Consultation where necessary with a dietician or doctor, especially if you want to modify multiple food groups.

Milk fat and digestive problems

Not only lactose or milk proteins can cause symptoms; also milk fat plays into it for some people. Fat is delivered in small globules and requires bile and enzymes to be broken down properly. When that digestion goes awry, you can notice it that way:

In people with digestive problems (such as bile problems, PDS or pancreatic problems), this can lead to:

• Steatorrhea (oily stools): Shiny, sticky stools that are difficult to flush.
• Nausea: especially after eating whole milk products or cheese.
• Bloating: A feeling like there's a brick in your belly.

Notice especially after full dairy these signals, then it pays to play with portions and fat content. Vegetable alternatives are often more digestible and can then be a godsend.

Milk and skin complaints

SNot all reactions take place in your gut. Some people especially see skin changes after dairy, even without an allergy. It can look like this:

• Acne: Exacerbation of pimples, especially around the chin and jawline.
• Eczema: Dry, itchy spots that flare up after dairy products.
• Itchy rash: bumps or red spots, with no apparent cause.

This is not always recognized in the medical community, but many people notice improvement when they omit dairy. Suspected causes are hormonal components in milk and mild inflammation.

What if you just don't feel good after milk?

Sometimes there is no clear diagnosis, but simply feel better without cow's milk. You may take that seriously. You can then explore in a calm and structured way what works for you:

You can think of:

• An elimination and reintroduction test: stop for a while and then try again gradually, under supervision.
• Choosing plant-based alternatives: Think oat, soy, almond or rice drinks.
• Consciously read labels: milk is sometimes in places where you don't expect it (chips, cold cuts, soup, candy).
• Tuning into your own pattern of symptoms: your experience counts, even if there is no diagnosis on it.

Cow's milk is complex, just like your body

Cow's milk contains lactose, fats, proteins and exorphins. All of those components can interact with your body in different ways. Sometimes that's positive, sometimes a little less so. And both are allowed to be there.

At NooMooo, it's not about thinking black and white, it's about finding what's right for you works. Whether you're lactose intolerant, sensitive to protein or just function better without milk. We're here for practical tips, honest stories and reliable info. Without fuss, with a touch of humor.

What's in cow's milk and which components can cause symptoms

Cow's milk consists of water, lactose (milk sugar), proteins (especially casein and whey), fats and vitamins and minerals. In some people, lactose or milk proteins in particular cause symptoms. Sometimes milk fats or skin reactions also play a role.

What is lactose intolerance and what symptoms are associated with it

Lactose intolerance occurs when too little lactase in the small intestine is. Undigested lactose enters the large intestine where bacteria begin to ferment. Complaints that are common are a bloating, flatulence, abdominal pain or cramping and sometimes diarrhea.

What is cow's milk allergy and how is it different from cow's milk intolerance

Cow's milk allergy is a immune response to milk proteins and can quickly cause symptoms such as skin rashes, swelling, tightness in the chest, vomiting or diarrhea. Cow's milk intolerance is not an allergy. It involves a sensitivity For milk ingredients with often delayed symptoms such as abdominal pain, fluctuating stools, fatigue, nausea and headaches.

What are exorphins from milk and can they cause symptoms

Exorphin are small peptides released during the digestion of casein. In people who do not break down these peptides properly, symptoms such as difficulty concentrating may occur, brain fog, sleep problems, irritability, gloominess and, in children, behavioral changes. The evidence is not unequivocal, but some people notice improvement when they avoid casein.

Can milk fats or milk products cause skin complaints

In some people milk fats digestive complaints such as oily stools, nausea and bloating. In addition, some find that dairy products increase the skin affect with complaints such as acne, eczema or itchy rash. Some see improvement when dairy is omitted.