Move over, green tea. You’ve enjoyed the health limelight for long enough. It’s time for black tea to move back into our kitchens and our cups, for comfort, for energy, and for the health benefits, too.
Tea is the world’s most popular beverage after water, easily surpassing coffee, which runs a distant third. In England, tea plays a part in almost every aspect of life and society. Receive bad news? A cup of tea, well-sugared is the remedy. Investigating a murder? A cup of tea, please. Cricketers break for tea and sandwiches before returning to the pitch. Miss Marple always seems to have a cup in hand. Ladies gather for afternoon tea. Putting the kettle on is the British response to just about every situation. Black tea is the most popular of the tea varieties, accounting for more than 90 percent of all tea consumed in the west and 78 percent of tea globally. Have we been missing something?
The six classes of tea–green, yellow, white, oolong, black, and pu-erh (fermented tea), come from the same Camellia sinensis plant, a shrub native to China and India. Each class of tea is manufactured according to a precise sequence of steps that include oxidation, stopping the oxidation, forming the tea and drying it. Black tea goes through the most rigorous oxidation—exposure to air—which produces the rust red color of “black” tea. Leaves go through further processing, first dried, then hand-rolled and crushed, followed by sun-drying and further processing, which releases beneficial properties like free amino acids and gives the tea its distinct flavor and appearance.
While green tea has been anointed the “healthy” tea in recent years, black tea shares many of those benefits and—depending on leaf variety, steeping time, and water temperature—may even exceed them.
The health benefits of black tea
- Boosts energy. The relatively modest presence of caffeine in tea— 70 mg in a cup of black tea compared to 200 mg for coffee—offers a gentle, sustained energy boost. Tea enhances blood flow to the brain without over-stimulating the heart. It also stimulates our metabolism and respiratory system. This ‘clean’ burst of energy comes from a mix of theophylline, theobromine and caffeine.
- Relieves stress. Black tea helps us relax when we’re stressed or unwinding after a hectic day. We can thank the amino acid L-theanine for that feeling of being more relaxed and able to concentrate better. Studies show that black tea also reduces levels of the stress hormone cortisol when we drink it regularly in moderate amounts.
- Builds immunity. Black tea contains antigens that help boost our immune response. It also contains tannins that fight viruses and protect against influenza, stomach flu and other common viruses. Consider this: researchers from Brigham and Women’s Hospital and Harvard Medical School in Boston and the University of New Hampshire, Durham, wanted to see if the alkylamine antigens naturally found in tea boost the body’s immune system. They asked volunteers to drink either five small cups of black tea or coffee daily for up to four weeks. After only two weeks, gamma-delta T cells from tea drinkers could produce more disease-fighting chemicals, while those of coffee drinkers did not.
- Supplies cancer-fighting antioxidents. Black tea contains polyphenols–antioxidants that help block DNA damage from tobacco and other toxic chemicals. They include catechins, theaflavins, tannins, and flavonoids and can help prevent certain types of cancers. According to 82-year-old John Weisburger, PhD, senior researcher at the Institute for Cancer Prevention in Valhalla, N.Y., studies of humans and animals confirm that antioxidants in both black and green teas are highly beneficial to our health.
“I’ve published more than 500 papers, including a hell of a lot on tea,” says Weisburger, who drinks 10 cups daily. “I was the first American researcher to show that tea modifies the metabolism to detoxify harmful chemicals, in an interview with WebMD. Whether it’s green or black, tea has about eight to 10 times the polyphenols found in fruits and vegetables. In my lab, we found that green and black tea had identical amounts of polyphenols.”
- Prevents tooth decay. The polyphenols in black tea inhibit both plaque formation and bacteria growth that promotes cavities and tooth decay. Black tea also reduces the stickiness of bacteria that accumulates in dental plaque, which produces acid and ultimately dissolves tooth enamel and causes cavities.
- Contributes to healthy hearts. A 2009 meta-study of data from nine studies–involving 4378 strokes among 194,965 individuals–showed that those who drank at least three cups of tea each day had a 21 percent lower risk of a stroke than those who drank less than one cup. Another study found that black tea helped lower total triglyceride levels by about 36 percent in three months. This same study also found a greater than 400 percent increase in the antioxidant concentration of participants’ blood. Higher antioxidant levels are linked to less inflammation and oxidative stress.
- Helps fight cancer with catechins. Tea contains theaflavins, catechins, quercetin and other polyphenols recognized for their anti-cancer properties. Drinking tea is linked to reduced risks of squamous cell carcinoma of the skin, head and neck cancers, and adult leukemia, as well as gastric, endometrial, colorectal, and prostate cancer. Women who consume the most flavonoids, a key antioxidant in tea, are significantly less likely to develop endothelial ovarian cancer—the fifth leading cause of cancer death among women. To reach this conclusion, researchers studied the dietary habits of more than 170,000 women for three decades. They concluded that just two cups of black tea every day was associated with a 31 percent reduction in risk for this cancer.
- Lowers risk of diabetes. In countries where black tea is consumed, rates of type 2 diabetes are lower. In 2009, researcher Ariel Beresniak of Data Mining International in Geneva and his colleagues looked at black tea consumption in 50 countries and compared it to rates of diabetes and cancer, and to respiratory, infectious, and cardiovascular diseases in each country. Statistical analyses showed that diabetes rates were low in countries where people drank the greatest amount of tea per capita, like Ireland and the U.K. Black tea contains complex flavonoids associated with several potential health benefits, the researchers noted. The brewing process releases these flavonoids. While the study found a mathematical association between black tea consumption and type 2 diabetes rates, it did not prove causality.
- Balances blood sugar. Drinking black tea promotes healthy blood sugar levels, according to a study published in the May 2012 edition of the journal Preventive Medicine. Researchers examined the effects of black tea on blood sugar in healthy adults. Participants drank three cups of black tea (no milk or sugar) for 12 weeks and had their glucose and lipid levels tested against baseline. Black tea reduced blood sugar by 18 percent, considered by researchers to be highly significant. They also noted a significant reduction in triglycerides and a bad form of cholesterol called low-density lipoprotein.
- Protects against bone loss. Regular tea drinkers may have stronger bones and a lower probability of developing arthritis due to the phytochemicals in tea. According to one study conducted by a team of researchers in Western Australia and published in The American Journal of Clinical Nutrition, elderly women who drank tea had higher bone density in their hips and less bone loss over time than women who didn’t drink tea. This was consistent with earlier studies suggesting tea drinking may protect against bone loss and osteoporosis. In the study, Australian researchers surveyed 275 women between 70 and 85—participants in a larger five-year study of calcium supplements and osteoporosis—about how much black and green tea (but not herbal teas) they drank. Bone density measurements of their hips were taken at the beginning and end of the study. The results showed that the regular tea drinkers had higher bone density in two sites in the hip compared with non-tea drinkers. The bone mineral density in the tea drinkers was higher than in the non-tea drinkers, and the tea drinkers also lost less bone density over a four-year period compared with non-tea drinkers. Quantity didn’t seem to matter. The researchers did not find a relationship between the number of cups of tea consumed per day and bone mineral density.
Making the best cup of tea
The “best” cup of tea may depend on whether you want to maximize the biochemicals or make a brew that is pleasing to the palate. Because the chemical components of different varieties can vary widely, tea aficionados recommend focusing on enjoying the distinct flavor profile of the tea.
- Use cold, clean water that hasn’t been boiled. It can be filtered, bottled or from the tap but preferably not distilled as this can result in a flat taste.
- Bring the water to a rolling boil then let cool for a minute until it’s 195° to 205° F. (tiny bubbles on the surface). The right water temperature will help you achieve that right balance of tannins.
- Use one tea bag or 1 to 2 teaspoons of tea leaves per 6 to 8 ounces of water, depending on personal preference.
- Use a teapot to make the tea. (Obviously you can use a mug or a cup but we are talking about the “best” cup of tea.)
- Allow tea to steep from 3 to 5 minutes depending on whether you want a milder or stronger brew. If you prefer a strong tea, use more leaves rather than steeping longer, as this makes the tea bitter.
- Since tea leaves expand some 3 to 5 times in size, a basket-style infuser will give the tea leaves more room to expand and infuse their flavors than a ball-style, unless it is very big.
Fine premium teas are like fine wines and should be enjoyed with no additions to allow the distinct scents and flavors to emerge. Many tea drinkers in the U.K. and Ireland drink milk in their tea, whether made with leaf tea or tea bags. Lately, though, there have been reports that adding milk to tea can negate the health benefits. A 2007 study published in the European Heart Journal found that the casein in milk blocked the ability of the flavanols in tea to relax and expand to keep blood pressure healthy. The study was small (16 people) so clearly not definitive. And British health experts doubt that adding some milk to tea would negate all the health benefits tea offers, noting there were “about 200 bioactive compounds in tea” and the effect of milk vasodilation “does not necessarily mean milk negates the other effects of tea.”
Catherine Collins, a dietician and spokesperson for the British Dietetic Society, pointed out that drinking tea with milk would boost calcium intake. She added, “There are benefits for tea, with or without milk, so keep on drinking.”
Miss Marple would agree.
Tea can be a fascinating study on par with that of wine. The Tea Enthusiasts’ Handbook and Tea: History, Terroirs, Varieties provide excellent overviews and introduction to the art of making and enjoying tea.