Does Mixing Green Tea with Milk Reduce Its Effect? The Scientific Verdict

November 19, 2025 •

4 min read

Recent scientific research presents conflicting evidence on the interaction between tea and milk, making many wonder: does mixing green tea with milk reduce its effect? While some studies indicate milk proteins can inhibit antioxidant absorption, others report no such impact, leaving the verdict unclear.

Quick Summary

Conflicting studies exist on whether adding milk to green tea reduces its beneficial effects. The primary concern involves milk proteins potentially binding to the tea's powerful antioxidants, catechins, and inhibiting their absorption.

Key Points

Conflicting Evidence: Scientific studies offer mixed results on whether milk negates green tea's benefits, with some showing reduced antioxidant activity while others find no significant impact.
Catechin and Casein Interaction: The primary mechanism for reduced effect is the potential binding of green tea's antioxidants (catechins) with milk's proteins (casein), which can inhibit absorption.
Alternatives are Safer: For those wanting to maximize antioxidant intake, plant-based milks like soy, almond, or oat milk are recommended as they do not contain casein.
Still Beneficial (with Milk): Even with milk, green tea retains some health benefits; it's just that the full antioxidant effect may be reduced, not entirely eliminated.
Consider Health Goals and Taste: The decision to add milk depends on your priorities—taste preference or maximizing antioxidant intake.

For centuries, green tea has been lauded for its powerful antioxidant properties, attributed mainly to compounds called catechins. However, in modern Western culture, it is common practice to add milk to tea for taste and creaminess. This has led to a long-standing debate: do these two ingredients, one renowned for its health benefits and the other a daily dietary staple, counteract each other when combined?

The Antioxidant and Protein Interaction

The central argument behind the theory that milk reduces green tea's benefits focuses on the interaction between catechins and milk proteins. Green tea is rich in polyphenols, particularly catechins like epigallocatechin gallate (EGCG), which are responsible for fighting free radicals and promoting cellular health. Milk, on the other hand, contains proteins, most notably casein. Scientific studies suggest that casein may bind to the catechins, forming complexes.

This binding action can potentially make the catechins less available for absorption by the body. The result is a reduction in the tea's antioxidant activity. For example, a 2009 study on black tea, which also contains catechins, found that adding milk blunted the tea's ability to improve blood flow in a group of healthy women. This suggests that the physiological effects of the tea were inhibited by the milk proteins. Another study using green tea capsules with milk showed an inhibition of the typical metabolic boost.

The Counter-Argument and Nuanced Findings

However, the scientific picture is far from definitive. Several studies present a more complex or even contradictory view. For instance, a small human study from 2001 found that adding milk to black tea had no effect on the absorption of flavonols (a type of flavonoid). The researchers concluded that flavonol bioavailability was not affected. More recently, research published in 2024 concerning matcha green tea indicated that milk did not significantly affect the absorption of catechins.

These conflicting results may stem from variations in study design, including the type and amount of tea and milk used, preparation methods, and the sample size. Some researchers also propose that the binding of catechins to proteins isn't necessarily a bad thing. Milk proteins could potentially act as carriers, protecting catechins from degradation in the harsh intestinal environment and aiding in their delivery and effectiveness. Ultimately, the interaction is complex and not fully understood, but it's clear that it isn't an all-or-nothing scenario.

Alternatives to Cow's Milk

For those concerned about the potential reduction in antioxidant benefits, there are several milk alternatives to consider. Plant-based milks like soy, almond, or oat milk do not contain casein, the specific protein thought to bind with catechins.

Soy Milk: A good option, as it does not contain casein.
Almond Milk: Often praised for its neutral flavor, which won't overpower the delicate taste of green tea.
Oat Milk: Offers a creamy texture similar to dairy but without the same protein interaction concerns.
Coconut Milk: Provides a rich, distinct flavor that complements green tea well.

Experimenting with these alternatives can allow you to enjoy a creamy green tea drink while retaining more of its potential health benefits. Some people also opt for alternative sweeteners like honey or lemon instead of milk to avoid any interference.

Plain Green Tea vs. Green Tea with Milk


Feature	Plain Green Tea	Green Tea with Milk
Catechin Bioavailability	Optimal; no protein interference.	Potentially reduced, depending on brew time and individual factors.
Antioxidant Effect	Maximum potency; best for those seeking full health benefits.	Potentially blunted due to protein binding; still provides some benefit.
Flavor Profile	Earthy, grassy, and sometimes astringent.	Creamy, smoother, and less bitter.
Nutritional Content	Virtually calorie-free; rich in antioxidants and L-theanine.	Adds calories, protein, and calcium from milk.
Heart Health	Studies show potential benefits like improved blood flow.	Research on the impact is conflicting, with some studies showing a reduced effect.

Making an Informed Choice

Whether you add milk to your green tea depends on your personal preferences and health goals. If you are drinking green tea specifically for maximum antioxidant intake, consuming it without milk is the safer and more widely recommended option. However, if you prefer the taste of a green tea latte or find plain green tea too bitter, adding milk is not harmful. You will still gain some benefits from the tea, just potentially in a reduced capacity.

For those focused on weight management, it is also crucial to consider the added calories and sugar that can come with milk tea, as plain green tea is a zero-calorie drink. Regardless of your preference, enjoying a variety of antioxidant-rich foods and beverages is the most effective strategy for promoting overall health. The debate over green tea and milk highlights that while food chemistry can be complex, moderation and mindful choices are always key.

The Brewing Temperature Effect

Another factor to consider is the effect of temperature. Some research suggests that longer brewing times may lead to better absorption of antioxidants, regardless of whether milk is added. Also, it is believed that adding milk after the tea has been brewed and cooled slightly might reduce the potential for protein-catechin binding compared to adding milk to very hot tea. However, the research on this specific effect is limited and requires further investigation.

Conclusion

So, does mixing green tea with milk reduce its effect? The answer is nuanced, with conflicting scientific evidence and many variables at play. While the protein-catechin binding theory suggests a reduction in antioxidant bioavailability, some studies show no negative impact. The choice to add milk ultimately comes down to a balance of taste preference versus the desire to maximize antioxidant benefits. For those seeking the full potency of green tea, drinking it plain is the most certain path. But for those who enjoy the creamy flavor, adding milk is not an unhealthy practice, though the antioxidant delivery may be slightly diminished.

Scientific Opinion on the Safety of Green Tea Catechins

Frequently Asked Questions

No, it is not considered harmful to mix milk with green tea. However, if your goal is to maximize the antioxidant benefits, it's better to drink it plain, as milk proteins may slightly reduce the absorption of catechins.

The main theory is that casein, a protein in milk, can bind to catechins, the antioxidant compounds in green tea. This binding action can make the catechins less bioavailable, or absorbable, by the body.

Yes, plant-based milks like soy, almond, or oat milk are good alternatives. They do not contain casein, so they are less likely to interfere with the absorption of green tea's catechins.

It may specifically affect the antioxidant properties of the catechins. Other components and overall benefits of consuming green tea are likely not completely negated, but could be slightly diminished.

While there is no definitive timeframe, some suggest waiting an hour or two to allow for maximum absorption of the tea's beneficial compounds before consuming dairy. However, the evidence on this is not conclusive.

Green tea's potential role in weight loss is linked to catechins and caffeine boosting metabolism. Mixing with milk may slightly reduce this effect due to protein binding. Additionally, adding milk adds calories, which could counteract the low-calorie benefit of plain green tea.

Some research suggests that adding green tea extract to milk before heating can increase binding, so preparing it at lower temperatures or adding milk after brewing might be beneficial. However, more research is needed on this specific effect.