Does milk lose nutrients when added to coffee? A deep dive into dairy and your brew

October 9, 2025 •

4 min read

According to a study conducted by Nestlé Research, adding milk to coffee does not prevent the absorption of its antioxidants, and in some cases, may even enhance anti-inflammatory effects. This challenges a common misconception and prompts the question: does milk lose nutrients when added to coffee or does it simply complement it?

Quick Summary

The nutritional value of milk remains largely intact when added to coffee, despite minor heat-induced changes to some vitamins. While coffee's acidity can denature milk proteins, this process does not destroy their core amino acids or overall nutritional content. Some interactions may even increase the bioavailability of certain compounds, offering additional health benefits.

Key Points

Nutrients Remain Stable: The core nutritional components of milk, including protein, calcium, and fat, are not significantly lost or destroyed when added to coffee.
Protein Denaturation is Normal: Heat causes milk proteins to denature or unfold, which is a standard process that does not eliminate the proteins' amino acid value for the body.
Vitamin Loss is Minimal: While some water-soluble vitamins like B2 and B12 can degrade with heat, the quick process of adding milk to hot coffee does not cause a nutritionally significant loss.
Acidity Causes Curdling, Not Ruin: The acid in coffee can cause milk to curdle, but this is a cosmetic change to the protein structure and does not make the milk unsafe or devoid of nutrients.
Antioxidant Interaction is Complex: The interaction between milk proteins and coffee's polyphenols is still debated, with some studies showing minimal or even beneficial effects on bioavailability, rather than a negative one.
Coffee with Milk Adds Nutrients: Far from destroying milk's benefits, adding it to coffee provides a nutritional boost of calcium and other vitamins that black coffee lacks.
Consider your Goals: Whether adding milk is a 'good' or 'bad' decision depends on your personal health goals, such as managing calorie intake, acidity, or avoiding lactose.

The Science of Milk and Coffee

For years, a persistent myth suggested that the heat and acidity of coffee could somehow neutralize or destroy the nutritional benefits of milk. However, recent research in food science offers a more nuanced and reassuring perspective. When milk is added to coffee, the primary constituents of milk—protein, calcium, and fat—are not fundamentally compromised or eliminated. The interaction is primarily a physical and chemical process that changes the texture and flavor, rather than an irreversible degradation of nutrients. This section explores the specific interactions and how they affect the nutritional profile of your morning cup.

The Impact of Heat on Milk Components

One of the main concerns revolves around heat damage. Milk is often heated to a certain temperature for lattes and cappuccinos or mixed directly with hot-brewed coffee. So, how does this affect the milk?

Protein Denaturation: The proteins in milk, particularly whey protein, can denature or unfold when exposed to high heat. While this sounds alarming, it is a normal process that also occurs during digestion. Denaturation simply alters the protein's structure, not its fundamental amino acid content. The body will still break down these amino acids and use them effectively. In fact, this process is what helps create the desirable foam in lattes.
Vitamin Degradation: Heat can cause some depletion of water-soluble B vitamins, such as riboflavin (B2) and B12. However, the level of loss is dependent on the temperature and duration of heating. The quick mix in a coffee cup is unlikely to cause a significant loss compared to prolonged boiling. For most adults, milk is not the sole or primary source of these vitamins, so the impact is minimal.
Calcium Stability: Contrary to some beliefs, calcium is remarkably stable and is not significantly affected by the heat of coffee. While some studies note minimal changes, the bioavailability remains intact, meaning your body can still absorb and use the mineral effectively. The small amount of calcium loss from caffeine's mild diuretic effect is also easily offset by the calcium provided by the milk itself.

The Role of Acidity and Polyphenols

Coffee is naturally acidic, and some worry that this could cause a negative reaction with milk. This is why milk can sometimes curdle in coffee, especially with lighter, more acidic roasts.

Curdling: Curdling is caused by the acid in coffee denaturing the milk's casein protein, causing it to clump. This is primarily a cosmetic issue and does not render the drink unsafe or nutritionally void. The protein is still present and digestible.
Polyphenol Interaction: Coffee is rich in antioxidants called polyphenols, which provide many of its health benefits. There has been some debate over whether milk proteins bind with these polyphenols and reduce their absorption. However, recent studies have offered conflicting and often reassuring findings. Some research suggests certain milk proteins may enhance the bioavailability of polyphenols, while others report minimal or no negative impact on overall absorption. The consensus leans towards the idea that the health benefits of both are largely preserved.

Milk vs. Cream vs. Plant-Based Alternatives

When deciding what to add to your coffee, it's worth considering the different nutritional profiles of various options. Each provides a unique set of nutrients and flavor characteristics.


Feature	Cow's Milk	Cream / Half-and-Half	Plant-Based Milks (e.g., Oat, Almond)
Calories	Moderate (varies by fat content)	High	Variable (often lower than dairy)
Fat Content	Varies (whole, 2%, skim)	High	Low to moderate
Protein	Excellent source of high-quality protein	Contains some protein	Variable (soy and pea milks are higher)
Calcium	Rich, bioavailable source	Contains some calcium	Fortified source, bioavailability varies
Micronutrients	Contains B vitamins, potassium, etc.	Fewer vitamins compared to milk	Variable, many are fortified with vitamins/minerals
Acidity Buffering	Very effective at reducing acidity	Effective at reducing acidity	Variable effectiveness
Considerations	Lactose intolerance is a factor	High fat and calorie count	Additives, sugar content, and fortification levels vary

Comparing Different Milks in Coffee

Cow's Milk: A standard choice for good reason, providing a solid nutritional boost of protein, calcium, and vitamin D. The fat content affects calories and creaminess, allowing for personalization.
Cream/Half-and-Half: These offer a richer, more luxurious mouthfeel but come with a higher fat and calorie count. Nutritionally, they provide less protein and fewer vitamins compared to standard milk.
Plant-Based Milks: Options like almond or oat milk are popular alternatives for those with lactose intolerance or specific dietary preferences. Their nutritional content depends heavily on fortification, so it is essential to check the label for added nutrients like calcium and vitamin D.

Conclusion: Your Brew, Your Choice

The question, does milk lose nutrients when added to coffee, can be answered with a reassuring 'no' in most practical scenarios. While minor, specific nutrient changes may occur due to heat and acidity, the core nutritional value of milk—namely its protein, fat, and calcium content—remains largely unaffected and available for your body to use. The potential interactions with coffee's antioxidants are still debated, but the evidence does not suggest a complete negation of health benefits. Ultimately, adding milk to coffee is a matter of personal preference, whether for taste, texture, or to mitigate acidity.

For those concerned about nutritional intake, the key takeaways are to use fresh milk, be mindful of any heat-sensitive vitamins (which are not a primary reason for drinking milk), and choose an option that aligns with your dietary needs and goals, whether that's traditional dairy or a fortified plant-based alternative.

Further Research

Journal of Dairy Science: Heat Treatment of Milk: A Review of its Effect on the Nutritional and Functional Properties. This academic article offers a detailed look at how different levels of heat affect milk's chemical composition and nutrients, expanding on the topic discussed here. [https://www.journalofdairyscience.org/article/S0022-0302(21)00407-2/fulltext]

Frequently Asked Questions

There is conflicting and inconclusive evidence on whether adding milk reduces the antioxidant benefits of coffee. Some studies suggest a minimal impact, while others propose certain interactions might even be beneficial.

No, coffee does not cancel out the calcium in milk. A minimal amount of calcium may be lost due to caffeine's diuretic effects, but the calcium from the milk is still largely absorbed by the body, and the amount added is enough to offset any small loss.

Yes, the heat from coffee can denature milk proteins, particularly whey protein, but this process does not destroy their nutritional value. Denaturation is a normal process that happens during digestion and doesn't affect the amino acid content.

Milk curdles in coffee due to the interaction of the coffee's acidity with the milk's casein protein. This is a normal chemical reaction and doesn't mean the milk is spoiled or that the resulting drink is unsafe to consume.

Some heat-sensitive, water-soluble B vitamins in milk, like B2 and B12, can be partially degraded by heat. However, the exposure time and temperature in a typical cup of hot coffee are not long or high enough to cause a significant or nutritionally meaningful loss.

To minimize any potential heat impact on sensitive vitamins, add milk to coffee that has cooled slightly. You can also add cold milk first, as it helps cool the coffee and prevent immediate curdling with highly acidic roasts.

Yes, a coffee with milk can be a healthy part of a balanced diet. It provides the benefits of both beverages, adding valuable nutrients like calcium, protein, and vitamin D from the milk while maintaining coffee's antioxidant properties.