Tea With Milk
Good, Bad or Harmful?

A yet unsolved mystery of tea is this: Why is green tea associated with more health benefits than black tea? Scientists still cannot agree that green tea contains more antioxidants than black tea. Can milk be the answer?

People seldom add milk to green tea, but it is more common for black tea.

It is not an easy one to call, but existing evidence seems to say that milk dilutes some of tea's health benefits, especially for people suffering from heart problems and diabetes.

So, is drinking tea with milk bad for health?

Two 1998 and 2001 studies do not find any evidence that adding milk reduces tea health benefits.

Researchers found that milk does not interfere with the absorption of a tea compound called catechin, to which scientists attribute most of green tea health benefits.

A 2002 study suggests otherwise. Researchers found that brewed tea, when added to the fat cells of laboratory rats, raises insulin activity by more than 15 times.

Adding lemon to the tea did not affect the insulin-potentiating activity. But adding 50 grams of milk decreased the activity by 90%.

Another 2006 review paper by Cheng remarked that while it is generally accepted that green tea protects against heart disease, it is more controversial for black tea, especially when milk is involved. To quote him:

Another 2006 review paper by Cabrera suggested that although drinking tea with milk does not interfere with the absorption of catechins, but it may degrade its antioxidant potential:

A 2006 German study found that adding milk to black tea destroys its ability to protect against heart disease. The researchers found that drinking black tea significantly helps the arteries to relax and expand to keep blood pressure healthy.

Catechin is responsible for this beneficial effect by stimulating the production of chemical nitric oxide. But animal milk contains proteins called casein. These proteins bind to the catechins, reducing their concentration and effectiveness.

Due to the complexity of the study, only 16 human subjects participated. The researchers also did tests on rat tissue.

Professor Steptoe said that as there were about 200 bioactive compounds in tea. The apparent harmful effect of milk "does not necessarily mean milk negates the other effects of tea."

If you drink tea with milk, try using soya milk. Soya milk contains lecithin that has a different molecular structure to casein, and so is unlikely to bind to tea catechin the way casein does.

Dubey P, Sundram KR, Nundy S. Effect of tea on gastric acid secretion. Digestive diseases and sciences. 1984 Mar; 29(3):202-6.

Lorenz M, Jochmann N, von Krosigk A, Martus P, Baumann G, Stangl K, Stangl V. Addition of milk prevents vascular protective effects of tea. European Heart Journal. 2007 Jan;28(2):219-23. Epub 2007 Jan 9.

van het Hof KH (1998). Bioavailability of catechins from tea: the effect of milk. Eur J Clin Nutr 1998:52:356-9.

Hollman PC (2001). Addition of milk does not affect the absorption of flavonols from tea in man. Free Radic Res 2001;34:297-300.

Tsung Cheng (2006). All teas are not created equal. The Chinese green tea and cardiovascular health. International Journal of Cardiology;108:301-308.

Cabrera Carmen (2006). Beneficial Effects of Green Tea - A Review. Journal of the American College of Nutrition;25(2):79-99.

Anderson RA, Polansky MM (2002). Tea enhances insulin activity . J Agric Food Chem 50:7182-7186.

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