The Benefits of Black Tea

Steeping black tea
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Black tea is made from the leaves of the Camellia sinensis plant, the same plant used to make green tea. The leaves are dried and fermented, giving black tea a darker color and richer flavor compared to green tea (which does not undergo the fermentation process).

Black tea contains a number of antioxidants, compounds that help the body fight free radicals (chemical by-products known to damage DNA). These antioxidants include catechin, thearubigins, and theaflavins, and catechins, substances known as flavonoids that are said to combat inflammation and support healthy immune function. Black tea also contains the amino acid L-theanine.

Does Black Tea Have Caffeine?

Black tea does have caffeine. In a study published in the Journal of Analytical Toxicology, researchers analyzed the amount of caffeine in different brands of brewed teas and found that a six-ounce cup of black tea contained between 14 mg and 61 mg of caffeine. The caffeine content increased with steeping time and with the serving size.

In their conclusion, the study's authors stated that, per ounce, the caffeine concentration in brewed teas tended to be lower than in specialized coffees and energy drinks, but similar to carbonated soda.

The Benefits of Black Tea

Here's a look at the research on black tea's health effects:

Cardiovascular Disease

Consumption of black or green tea may reduce blood pressure in people with high blood pressure or pre-hypertension, according to a report published in Nutrition Reviews in 2015. Researchers looked at 10 previously published studies evaluating the effects of tea on blood pressure in adults with high blood pressure or pre-hypertension. In their analysis, the report's authors found reductions in systolic blood pressure (the top number in a blood pressure reading) and diastolic blood pressure (the bottom number in a reading) with tea consumption.

In a 2013 review published in the Cochrane Database of Systematic Reviews, researchers examined previously published studies on the effects of black and green tea on cardiovascular disease prevention and found that black tea resulted in reductions in low-density lipoprotein (LDL) cholesterol and blood pressure. In their conclusion, the study's authors noted that there were very few long-term studies, but the limited evidence suggests that tea has favorable effects on cardiovascular disease risk factors.

Brain Health

Some research suggests that drinking black tea may improve blood vessel function, improve blood flow in the brain, and lower the risk of cognitive impairment. In a study published in PLoS One in 2015, for instance, researchers found that black tea consumption was associated with better cognitive performance in adults age 60 and older.

Other research has found no effect. A study involving adults over 60 found no association between black tea or coffee consumption and incidence of dementia or mild cognitive impairment. In addition, a 2018 population study of 3,844 men aged 65 and older living in the United States didn't find an association between black tea consumption and cognitive decline.

Diabetes

In a small study published in 2017, scientists discovered that a black tea beverage decreased blood glucose levels after consumption of a sugar drink (compared to a placebo beverage), however there was no significant difference in insulin levels. Additionally, a 2008 population study of adults living in Singapore found a suggestive inverse association between black tea intake and diabetes risk.

Cancer Prevention

While some research indicates that regular consumption of black tea may reduce cancer mortality, other studies report no cancer-related benefits of black tea intake. For instance, tea consumption was not found to reduce the risk of prostate cancer, endometrial cancer, and certain other types of cancer in some studies. Furthermore, research suggests that black tea consumption may be positively associated with increased risk of overall breast cancer (however, other research has found no effect on breast cancer risk).

Types of Black Tea

Here are some common types of black tea:

  • Orange pekoe
  • Assam
  • Keemun
  • Darjeeling
  • Ceylon
  • Nilgiri
  • Lapsang souchong
  • Yunnan

The most common type of black tea sold in grocery stores is orange pekoe. In addition, black tea is commonly found in the following blends:

  • Earl grey tea
  • English breakfast tea
  • Irish breakfast tea
  • Chai tea

Side Effects

In some individuals, high doses of caffeine may lead to a number of adverse effects (such as anxiety, increased heart rate and blood pressure, and the worsening of ulcer symptoms).

Little is known about the long-term health effects of black tea when taken in large amounts. Black tea contains fluoride and other substances in trace amounts, such as arsenic and boron. While black tea is a common beverage and consumption of three cups a day wasn't found to have adverse effects with respect to the micronutrients in tea, according to one study, little is known about the long-term effects of heavy consumption of black tea or what an acceptable limit might be.

Drinking Black Tea for Health

Although drinking black tea may offer certain health benefits, it has not been proven to prevent or treat any health condition. If you're considering drinking it for health purposes, speak with your healthcare provider first to discuss whether it's right for you.

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