Tea culture, which originated in Asia, has quickly spread to the West since the discovery of its numerous health benefits. Tea comes in a wide variety, each with a different chemical makeup that promotes different functions of your body. For example, green tea is said to bring balance and can calm your psyche, whereas black tea, with much higher caffeine content, can enervate your body and improve your mental acuity. But there are several beneficial effects that all tea shares, including reducing blood sugar, detoxifying your body, and preventing cardiovascular diseases and cancers. However, recent studies have shown that these positive effects are not shown in British tea drinkers, and the culprit behind this deviation is milk. British people have a habit of infusing milk into their afternoon tea, which prevents them from enjoying tea benefits.
Effects of Milk on Tea
The main reason why you should not mix milk with tea is that the milk protein casein binds and deactivates the polyphenol antioxidant epigallocatechin gallate (EGCG).
One of the primary properties of EGCG is that it allows your blood vessels to relax. Studies have shown that having 1 cup of tea per day can reduce your blood pressure, and increase your blood vessel flexibility and its responsiveness to pressure. This effect is totally wiped out if you drink it with milk, which explains why there is a high incidence of cardiovascular diseases in Britain.
The other major function of EGCG is that it can help prevent cancer. EGCG inhibits anti-apoptotic proteins in normal and cancer cells. Blocking these proteins allows cells to self-destruct after its life cycle which prevents them from abnormal proliferation. EGCG is especially conducive in preventing and treating cancers of the brain, prostate, cervix and bladder.
There is, however, one advantage to drinking tea with milk. Studies have shown that the casein also binds to a compound called tannin which is also found in tea. Tannin is slightly toxic and has been suspected for increasing esophageal cancer risk. Pouring milk into tea neutralizes tannin and eliminates this potential hazard.
To exact the maximum benefit from tea, you need to preserve as much EGCG and other antioxidants as possible. EGCG level is the highest in green tea and is much lower in black tea. EGCG is also temperature sensitive and loses its function when exposure to high temperatures. This is why you should never use boiling water to steep green, white or oolong tea. The optimal temperature to brew these teas is about 70 degrees Celsius or 160 degrees Fahrenheit. Let it sit for about 5 minutes before drinking.
Brewing black tea and herbal tea requires higher temperature. These teas are oxidized longer so you need boiling water to release its antioxidants.
If you find the flavor of pure tea unpleasant, instead of milk, add in a tablespoon of honey, some lemon juice or orange zest. Studies have shown that EGCG absorption is increased in more acidic solutions. For this reason, you may get even greater benefits if you drink citrus flavored tea.