Does Milk Block Antioxidants in Foods and Beverages?

茶，咖啡和水果等高抗氧化食品与许多健康益处有关。

Unfortunately, some studies have found that milk may block some of these beneficial compounds. However, other studies have found that milk has no effect.

So what should you believe? This article explores whether milk inactivates the antioxidants found in foods and beverages and if you should be concerned.

Antioxidantsare substances that prevent oxidation. Oxidation is a common chemical reaction in which a molecule gives up electrons.

In the body, oxidation can lead to the production of harmful free radicals, which are molecules that are missing an electron. Free radicals then take electrons from wherever they can, often causing damage to cells.

In fact, excessive free radicals may contribute to aging and the development of certain diseases, such as dementia and diabetes complications ( 1 , 2 , 3 ).

Antioxidants, which help eliminate these free radicals, come in many forms. Some are naturally produced within the body, while others come from your diet.

The vitamin C, vitamin E, beta-carotene and polyphenols found in fruits, tea and coffee are all compounds that act as antioxidants ( 1 , 4 ).

Many health experts believe that a diet high in antioxidants can help protect against the oxidative stress andinflammationcaused by free radicals. In turn, this may help reduce the risk of related health problems ( 5 , 6 ).

However, research has caused some people to worry that certain foods, namely milk products, may cause the antioxidants in foods to become inactivated, potentially negating their beneficial health effects.

Summary:

Antioxidants are produced in your body and can be found in your diet. They help fight free radicals, which can damage cells and contribute to aging and disease.

Many foods and beverages provide antioxidants.

Some of them are frequently consumed withdairy, and it’s these combinations that may be of concern.

这里有一些高抗氧化食物的例子and beverages commonly consumed with dairy:

• Coffee and cream
• Tea and milk
• Berries and yogurt
• 水果和奶油
• Oatmeal and milk
• Chocolate or cocoa and milk

Summary:

一些富含抗氧化剂的食物和饮料通常与牛奶产品配对。其中包括咖啡，茶，水果和巧克力。

Preliminary research has found thatmilkproducts may inhibit some antioxidants in certain foods and beverages.

最常见的例子是将牛奶添加到茶中，这是某些国家 /地区的习惯做法。

Several studies have found that adding milk to tea decreases its antioxidant capacity, or how effective its antioxidants are at preventing oxidation.

This effect is thought to occur because the milk proteincasein与抗氧化剂结合，降低其与有害自由基作斗争的能力（ 7 ).

However, the results have been conflicting. While some studies show that milk decreases the antioxidant capacity of tea, other studies show that it has no effect or even a positive effect ( 8 ).

For example, one study assessed three different measures of antioxidant capacity in tea. One test found that adding milk protein to tea reduced its antioxidant capacity by 11–27% ( 7 ).

However, another test using a different measure found that milk protein improved antioxidant capacity from 6% to 75% ( 7 ).

Yet, two other studies found that milk had no effect on the antioxidant capacity of tea in human participants ( 9 , 10 ).

The results are likely varied due to the type of tea, the type and amount of milk, the way the tea was prepared and the way the antioxidant capacity was measured.

Summary:

一些研究表明，将牛奶与茶混合可以减少或阻止其有益的抗氧化剂。但是，几项研究也发现了中性甚至积极作用。

Interestingly, similar results have been found with coffee, chocolate and blueberries, despite the fact that they don’t contain the same types of antioxidants.

One study found that milk reduced the antioxidant capacity of chocolate by approximately 30%, while another study found that milk negated the antioxidant effects of chocolate altogether ( 11 , 12 ).

Another study found that eatingblueberrieswith milk reduced the absorption of their polyphenols and blocked their antioxidant effects ( 13 ).

同样，不同类型的抗氧化能力coffeewas shown to decrease with the addition of milk. What’s more, the more milk that was added, the lower the coffee’s antioxidant capacity became ( 14 ).

Most evidence points to the fact that milk decreases the antioxidant capacity of some foods and beverages. However, the research is too conflicting to be sure.

Additionally, whether milk affects the health benefits of antioxidant foods and drinks, such as a decreased risk of heart disease, is not clear.

Summary:

Some research has shown that mixing milk with antioxidant-rich foods and beverages may reduce or block their ability to fight free radicals. However, the evidence is too conflicting to say for sure.

Even though the majority of studies found that milk decreases antioxidant capacity, many found that it only does so to a certain extent.

For example, several studies found that milk decreased the antioxidant capacity of foods or drinks by 30%, at the most ( 7 , 11 ).

That means that at least 70% of their antioxidant capacities remained unaffected.

It’s also important to understand that a decrease in the antioxidant capacity of a food does not directly translate to a decrease in its health benefits.

Currently, no studies have directly examined whether consuming dairy with high-antioxidant foods affects the health benefits, such as reducing the risk of dementia or heart disease.

但是，对茶对心脏病的影响的评论发现了有趣的结果。

It found that drinking tea protected against heart disease in most countries, but that the risk of heart disease in the UK and risk of stroke in Australia increased with every three cups of tea consumed per day ( 15 ).

The authors suggested that this difference could be because tea is usually consumed with milk in the UK and Australia. However, this is only a hypothesis, and there are many other potential explanations as well.

目前，证据太冲突了，无法确定牛奶是否会阻止几种抗氧化剂，还是抑制抗氧化剂食品的健康益处。

Summary:

尽管研究表明，牛奶可能会阻止食物中的某些抗氧化剂，但它可能不会抑制所有抗氧化剂。目前，没有证据表明它可以降低整体健康益处。

The best answer is to keep doing what you’re already doing.

There is currently no evidence that consuming dairy with antioxidant-rich foods reduces their overall health benefits.

In fact, there are many different factors affecting the antioxidant capacity — and even the nutrient content — of different foods.

Instead, the best thing you can do to maximize the health benefits of your diet is to consume a wide variety of antioxidant-rich foods and drinks.

If adding milk to your coffee is the way you like to enjoy it, don’t feel guilty about it.