The Perfect Cuppa:The benefits of tea (and a couple drawbacks)
Black tea is the second-most-consumed beverage in the world. It is an integral drink in so many cultures, from Great Britain to India to Turkey to China. Served by itself or flavored with bergamot (Earl Grey) or spices (chai), sweetened with raw honey or iced down with sugar like in the Southern United States, black tea is a versatile drink. And like so many traditional drinks (guarana, coffee, green tea, matcha, coca tea), it is loaded with health benefits.
While green tea gets a lot of credit for being the soldier against free radical attacks, black tea has similar levels of antioxidants. Catechins, theaflavins and thearubigins are three of the polyphenols—a type of antioxidant—that show up prominently in tea. Drinking tea may help decrease the effects of damage to the body’s cells, and could lead to a reduction in chronic illnesses.
Additionally, many of the health benefits discussed here are due in large part to the actions of a powerhouse of antioxidants in tea.
Flavonoids—a group of antioxidants found in many vegetables, fruits, red wine and chocolate—are quite prevalent in tea. And they could be the key to increased cardiovascular health. Tea decreases the chances of developing coronary heart disease.1 And for those who already have some cardiovascular risk factors, drinking about three cups of tea a day improves cholesterol and blood sugar levels.2
An essential part of cardiovascular health is our body’s blood pressure. According to a randomized controlled study, the consumption of black tea can contribute to improvements in both systolic and diastolic blood pressures.3 That said, other researchers found mixed results among studies.4
In one study, participants consumed either a black tea extract in tablet form or a placebo three times a day for three months. The researchers noted that those who consumed the actual black tea extract, as opposed to the placebo, saw a significantly lowered level of “bad” cholesterol, or LDL.5 Stroke A stroke, sometimes referred to as a “brain attack” in order to correlate the urgency of it to heart attacks, occurs when the blood vessels in the brain do not receive enough oxygenated blood. This usually occurs when there is a blood clot or a thickening of the blood vessels to create an obstruction, or when a blood vessel ruptures. Strokes are directly linked to poor cardiovascular health.
The good news is that an overwhelming majority of strokes are preventable. A study out of Sweden of nearly 75,000 men and women analyzed the cardiovascular health of the participants. When the researchers adjusted for other factors, they concluded that tea consumption—about four cups a day, to be exact—was significantly associated with a lower incidence of strokes.6
Higher blood glucose levels are not just of concern for those at risk for or living with diabetes. Elevated blood sugar also contributes to poor kidney function, cardiovascular conditions and even depression. Some studies have demonstrated a positive effect on blood glucose levels for regular tea drinkers. One theory is that components of tea—namely antioxidants—help promote insulin activity in the body.7
Research is inconclusive regarding how black tea improves the immune system. There are a few theories on why black tea may improve the immune system, and those mainly have to do with the brain-gut connection and antioxidants.8 The polyphenols in tea may also improve gut health by positively affecting the gut microbiome.
In addition to the antioxidative benefits, the tannins in tea, along with the warm water, can aid in digestion after meals. They have also been demonstrated to have anti-diarrheal qualities.9
The caffeine in black tea can help with focus and memory. However, the caffeine spike and drop isn’t as severe as that of coffee. Black tea drinkers often describe increased alertness at a level that doesn’t produce jitters or anxiety and that has a longer duration.10 The amino acid L-theanine plays a complementary role to the caffeine, promoting relaxation and improved focus.11
Black tea may help your body mitigate the negative chemical response to stress. Interestingly, tea has been shown to decrease stress by reducing the stress hormone cortisol, compared to a placebo. And subjectively speaking, tea drinkers report greater levels of relaxation.12
For quite some time, it was thought that caffeine-containing beverages were dehydrating. More recently, scientists are concluding that is only a concern when drinking many cups of caffeinated beverages (like five, six or more!).
All of the health benefits discussed here are most often seen when drinking black tea in moderation. This usually shakes out to about three or four cups a day.
When you go beyond that, you risk some of the negative aspects of drinking too much of it, including getting jittery from too much caffeine or perhaps some dehydrative effects.
Particularly because tea is a leaf, it is important to buy tea from a brand or source you trust. Leaf and ground vegetables are most vulnerable to pesticides and fertilizers. Additionally, many of the world’s tea farmworkers come from very poor regions. Look for third-party certifications that can attest to organic, fair trade and antideforestation standards.