Reactions to dairy products

Reactions to dairy can vary widely from person to person, and the biological mechanisms involved range from enzyme activity to hormonal and immunological responses. Here's a thorough review of how dairy can affect the body, including aspects like casomorphins, growth hormones, and mTOR:

lactose intolerance

• Mechanism: Lactose, the sugar in milk, requires the enzyme lactase to be broken down into glucose and galactose in the intestine. Many adults lose the ability to produce sufficient lactase, leading to lactose intolerance.
• Symptoms: Bloating, diarrhea, cramps, and gas resulting from fermentation of lactose in the colon.
• genetics: The ability to digest lactose in adulthood is linked to a genetic mutation that is more common in certain populations, such as those in Northern Europe.

Milk protein allergy

• Mechanism: The immune system reacts abnormally to proteins in milk, especially casein and whey proteins. This can lead to anything from mild itching to severe anaphylactic reactions.
• Symptoms: Skin rash, vomiting, diarrhea, breathing problems and in severe cases anaphylaxis.
• Difference from intolerance: This is an immunological response, while intolerance is enzymatic.

Casomorphins

• What it is: Casomorphins are bioactive peptides that are formed during the digestion of casein, the main protein in milk.
• Mechanism: These peptides bind to opioid receptors in the body, which can produce a morphine-like effect. This explains why some people may experience a “comforting” or addictive-like response to dairy products.
• Relevance: There is speculation that casomorphins may influence neurological conditions such as autism, although the research on this is controversial. In addition, they may disrupt intestinal permeability ("leaky gut").

Growth hormones and IGF-1

• What it is: Dairy products naturally contain insulin-like growth factor 1 (IGF-1) and can also stimulate the body's own production of this hormone.
• Mechanism: IGF-1 is an anabolic hormone that promotes growth and cell division. High milk intake has been linked to increased levels of IGF-1 in the blood, which may affect the risk of certain cancers, such as breast and prostate cancer.
• Hormones in milk: Commercially produced milk may contain traces of hormones from cows, such as estrogen and progesterone, especially if the cows are pregnant. This can have hormone-disrupting effects.

mTOR activation

• What it is: mTOR (mechanistic Target of Rapamycin) is an intracellular signaling pathway that regulates cell growth, protein synthesis and metabolism.
• Mechanism: Dairy products, especially those high in leucine (an essential amino acid), activate mTOR. Overactivation of mTOR has been linked to aging, insulin resistance, cancer, and other chronic diseases.
• Discussion: While mTOR is essential for growth and repair, chronic overactivation can be detrimental, leading to debate about the role of dairy products in the modern diet.

Gut health and microbiome

• Mechanism: For some, dairy products can disrupt the gut microbiome, especially if they contain lactose that is not digested. However, fermented dairy products like yogurt and kefir can provide probiotic bacteria that boost gut health.
• Inflammation: In individuals with milk sensitivity, the immune response to milk proteins can lead to inflammation and increased intestinal permeability.

Chronic inflammation

• Mechanism: For some people, milk proteins can act as a trigger for inflammatory responses, particularly in people with autoimmune conditions such as rheumatoid arthritis or Crohn's disease. This may be due to molecular similarities between milk proteins and the body's own tissues.
• Exception: Fermented dairy products such as cheese and kefir are often better tolerated, because proteins and lactose are partially broken down during the fermentation process.

Addiction and cravings

• Mechanism: Casomorphins may explain why dairy products like cheese are often highly addictive for some people. The combination of fat and protein with opioid-like peptides may produce a rewarding effect in the brain.
• Practical example: Cheese has been nicknamed "milk crack" because of its potentially addictive properties.

Skin reactions

• Mechanism: In some people, milk can trigger acne or other skin problems, likely due to increased levels of IGF-1 and changes in insulin response.
• Evidence: Studies have shown that skim milk in particular may be associated with increased acne incidence, possibly due to a higher insulin response compared to whole milk.

Immunosuppressive effects

• Mechanism: Some studies suggest that milk may affect the immune system by modulating levels of cytokines and inflammatory markers, although this is controversial and may vary between individuals.

Genetic variation

• Mechanism: Genetics play a big role in how we react to milk. This applies not only to lactase persistence, but also to how the body handles milk proteins and fats.

As we can see, reactions to dairy products are complex and influenced by a variety of factors, including genetics, gut health, immune response, and hormonal mechanisms. While some people tolerate milk well and even experience health benefits, others may experience anything from mild discomfort to serious health consequences. Key factors such as casomorphins, IGF-1, mTOR, and inflammatory responses show how milk can profoundly affect the body's physiology, making it a hotly debated topic in health and nutrition.

Overeating dairy products

Dairy-related overeating is a fascinating and complex phenomenon that can be explained by both biological and psychological mechanisms. Dairy products, especially cheese, seem to have an almost hypnotic attraction to some people, making them difficult to moderate. Here are some reasons why dairy products may trigger overeating:

Casomorphins and addiction mechanisms

• Mechanism: Casomorphins, which are formed during the digestion of casein, bind to opioid receptors in the brain. This can produce a mild sense of reward, not unlike the effects of morphine, which can lead to an “I can’t stop” feeling.
• Especially for cheese: Cheese is a concentrated source of casein, which enhances its effects. Many describe cheese as more addictive than other dairy products.

The combination of fat and salt

• Mechanism: Dairy products, especially cheese and butter, combine fat and salt in a way that is biologically very appealing to the human body. This combination activates the brain's reward system more powerfully than when fat or salt are consumed alone.
• Results: This can override satiety signals and lead to overeating.

IGF-1 and insulin response

• Mechanism: Dairy products, even those with low carb content, can stimulate insulin production and increase levels of IGF-1. This can interfere with the body's natural signals for hunger and satiety.
• Example: High insulin can lower blood sugar after a meal, which can trigger feelings of hunger again, even if you have recently eaten.

Hyperpalatability

• Mechanism: Modern processed dairy products are designed to be extremely tasty, with the perfect balance of fat, salt and texture, which can make them nearly impossible to resist and lead to overeating.
• Example: Think about how it can feel impossible to stop after “just one bite” of a delicious melted cheese or a creamy dessert.

Lack of natural satiety signals

• Mechanism: Dairy products that are processed or concentrated (like cheese or cream) have a low volume-to-calorie ratio. This means they provide a lot of calories without filling your stomach enough to send clear satiety signals to your brain.
• Example: It's easier to eat a large amount of calories from cheese than from a large steak.

Neurotransmitters and reward

• Dopamine: Dairy products stimulate dopamine release in the brain, which increases the feeling of pleasure and creates a form of positive reinforcement. This makes it tempting to continue eating even after the body has had enough energy.
• Serotonin: For some, the carbohydrates found in certain dairy products (like milk or yogurt) can increase serotonin production, providing a temporary feeling of well-being.

Comfort food and emotional eating

• Mechanism: Dairy products are often associated with nostalgia and comfort, as milk and cream are often used in childhood comfort foods. This emotional connection can make it difficult to eat them in moderation.
• Example: A bowl of ice cream can act as a kind of "emotional band-aid" during stress, but lead to overeating.

mTOR and signals for storage and growth

• Mechanism: Activation of the mTOR signaling pathway through amino acids like leucine, which are abundant in dairy products, can stimulate the body's growth and storage mechanisms, which may create a physiological urge to consume more energy to support this growth.
• Relevance: Dairy products are designed by nature to promote growth (especially in infants), making them calorie-dense and biochemically stimulating.

Social and cultural habits

• Mechanism: Dairy products are deeply integrated into the food traditions of many cultures, from cheese platters to creamy sauces, making it socially acceptable, or even expected, to eat a lot of them.
• Example: A cheese platter can easily lead to the "just one more bite" cycle, especially in social settings where food is shared and the experience is connected to hygge.

What can you do?

If dairy products lead to overeating, consider the following strategies:

• Limit your intake of processed dairy products like cheese, and instead focus on healthier varieties like natural yogurt or whole milk.
• Combine dairy products with filling foods like meat, so that the balance between protein and fat provides stronger satiety signals.
• Be aware of emotional eating and find alternative strategies to deal with stress or discomfort.
• Experiment with temporarily eliminating dairy products to see how your body reacts without them.

Overeating dairy products is an interaction between the body's physiology and psychological triggers, and it can be both natural and difficult to control. But understanding the mechanisms provides a good start to finding solutions that work for the individual.

SOURCES

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