Tea: A Beverage Steeped in History & Health Benefits

More than half of the American population and nearly 85% of millennials drink tea. No doubt thanks to the appealing, hydrating, and health-promoting qualities of true teas. Consuming tea has even proven to be a characteristic of, if not a track to, healthier beverage consumption patterns.¹

Derived from the plant Camellia sinensis, black, green, oolong, dark, and white teas are well-known for their health benefits. Throughout its nearly 5,000-year history, tea from the Camellia sinensis plant has been believed to help “purify the body” and “preserve the mind.” The earliest record of tea’s healing power dates back to China in 2737 BC.

Scientists have been testing these theories for decades. To date, researchers have identified and classified the bioactive compounds inherent in tea, and thousands of published studies support tea’s ancient health claims.

Teas derived from the Camellia sinensis plant contain thousands of health-promoting bioactive compounds, including polyphenolic compounds such as catechins like, (-)-epigallocatechin-3-gallate (EGCG), L-theanine, theaflavins, tannins, and flavonoids, as well as amino acids, caffeine, lignins, and xanthins.2 Black and green teas are rich sources of phytonutrients, which are responsible for some of their health benefits.

The whole-body benefits of tea are both immediate and long-lasting. As a virtually calorie-free beverage, tea can quench thirst, maintain adequate hydration, and provide a subtle boost of caffeine. From its benefits in weight control, oral health, and digestion to heart health, bone health, and cancer prevention, tea has both short and long-term health benefits.

Brain-Power Booster
Science has demonstrated the antioxidants in tea may have brain benefits.

Research has shown that diet and exercise may help blunt age-related neurodegeneration, protect against neurological disease, and enhance cognitive function.^3,4 The antioxidants in true teas are thought to play a role in protecting brain cells from environmental insults and inhibit oxidative damage. Through the action of its polyphenols, tea may play an important role in modifying the progression of age-related dementia and Alzheimer’s and Parkinson’s diseases.⁵ Research has reported that tea polyphenols, EGCGs, are bioavailable to the brain and may protect neurological function.

Researchers studied the effect of habitual tea drinking on the functional and structural networks in the brain. When compared to non-habitual tea drinkers, routine tea drinkers were found to have greater functional connectivity strength and suppressed hemispheric asymmetry in the structural connectivity network.⁶ Although this is the first research of its kind, this study suggests that habitual tea drinking has a protective effect on age-related brain decline. 

Black tea consumption has even been proven to improve attention. Bioactive components of tea like L-theanine and EGCG have been shown to enhance brain function. A study demonstrated that when subjects consumed two cups of black tea, they demonstrated greater levels of attention.⁷

Heart-Helper
Beyond the cognitive benefits of tea, research has also demonstrated its role in heart health. A recent review in Advances in Nutrition explored tea’s phytonutrients and determined that it should be considered or included as part of a healthy diet, thanks in part to its heart-healthy benefits.⁸

Research suggested there is an association between daily tea consumption and reduced risk of heart disease. Specifically, black tea consumption has even been linked to decreased risk for a heart attack and improved cardiovascular health.9,10 One of the health promoting compounds in tea, (-)-epigallocatechin-3-gallate or EGCG, has been shown to improve other indicators of heart health. EGCG may improve heart health through reduction in inflammatory markers, narrowing of arteries, and increase in antioxidant activity.¹¹

Tea & Type 2 Diabetes
Type 2 diabetes is considered a global epidemic.¹² Catechins in tea have been shown to help modulate blood glucose and improve insulin sensitivity, which may be beneficial for people with both type 1 and type 2 diabetes, although further research is needed.^13-19 Some studies suggest a link between drinking tea and a reduced risk of type 2 diabetes.¹⁴ While this is just preliminary research, it indicates the broad benefits of drinking tea.

Support Weight Goals
Tea contains no sodium, fat, carbonation, or sugar—it is virtually calorie-free. Research suggests tea consumers have a lower weight and waist circumference.20 This may be related to tea components’ ability to affect metabolism. Additional research suggests the catechins or bioactive compounds in tea, in combination with caffeine, are responsible for increasing energy usage in tea drinkers, which can have a weight-modulating effect.²¹

‘Tea-up’ Oral Health
Tea may contribute to oral health through various characteristics, including antibacterial properties and fluoride content, that may help protect against cavities and gum disease and may strengthen tooth enamel.^22-27 Research has demonstrated that 2-3 cups of green tea daily may play a role in reducing gum disease risk. While tea provides many oral health benefits, drinking tea is not a substitute for brushing and flossing.

Sip for Strong Bones
Although high caffeine intake has been suggested as a risk factor for reduced bone mineral density, drinking tea has been linked to higher bone density. Compared with non-tea drinkers, tea drinkers have been found to have a higher bone mineral density.^28-30 Tea may also boost bone-building markers and improve muscle mass, both of which may reduce the risk for osteoporosis and fracture.^31-34

From head to toe, true teas—such as those derived from the Camellia sinensis plant—have powerful, proven health benefits. Straight from the cup, tea is well-known for its brain-boosting, heart-protecting, chronic disease-reducing and oral and bone health-maintaining benefits. Whether black, green, oolong, dark, or white, the healthful properties of true teas span all varieties.

Steeping a cup using the “golden rules” below will help reap the science-backed benefits.

• Use a teapot
• Bring fresh, cold tap water to a full boil (Note: If water is heavily chlorinated or contains other objectionable odors, filter before boiling for best tasting tea)
• Use one teaspoon or one tea bag per cup
• Pour boiling water over tea and brew by the clock 3 to 5 minutes, and serve. For green and white teas, let the water cool for a few minutes before pouring over tea
• Recommended steep times: steep white for 1-3 minutes; green for 3 minutes; and black, oolong, and dark for 3-5 minutes.

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About Peter Goggi and the Tea Association of the USA: No stranger to tea, Goggi began his career at Unilever and spent 30 years working with Lipton Tea as part of Royal Estates Tea Co. and eventually served as president. He was the first American-born Tea Taster in the history of T.J. Lipton/Unilever and was also featured on The History Channel’s Modern Marvels. Currently, Goggi serves as the president of the Tea Association of the USA, Inc. Founded in 1899, the Tea Association of the USA, Inc. was formed to promote and protect the interests of the tea trade in the U.S. and is the recognized independent authority on tea. Members span the full tea supply chain, from growers to packers.

References

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2. Ferruzzi MG, Tanprasertsuk J, Kris-Etherton P, Weaver CM, Johnson EJ. Perspective: the role of beverages as a source of nutrients and phytonutrients. Adv Nutr. 2019 Nov 22. pii: nmz115. doi: 10.1093/advances/nmz115. [Epub ahead of print]
3. Scarmeas N, Luchsinger JA, Schupf N, Brickman AM, Cosentino S, Tang MX, Stern Y. Physical activity, diet, and risk of Alzheimer disease. JAMA. 2009 Aug 12; 302:627.
4. Alzheimer’s Association. (n.d.) Prevention and Risk of Alzheimer’s and Dementia: Heart-Head Connection. Retrieved from http://www.alz.org/research/science/alzheimers_prevention_and_risk.asp#heart
5. Mandel SA, Amit T, Kalfon L, Reznichenko L, Youdim MBH. Targeting multiple neurodegenerative diseases etiologies with multimodal-acting green tea catechins. J Nutr. 2008;138:1578S–83S.
6. Li J, Romero-Garcia R, Suckling J, Feng L. Habitual tea drinking modulates brain efficiency: evidence from brain connectivity evaluation. Aging. 2019; 11(11): 3876-90.
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8. Ferruzzi MG, Tanprasertsuk J, Kris-Etherton P, Weaver CM and Johnson EJ. Perspective: The Role of Beverages as a Source of Nutrients and Phytonutrients. Adv Nutr. 2019 Nov 22. pii: nmz115. doi: 10.1093/advances/nmz115. [Epub ahead of print]
9. Sesso HD, Gaziano JM, Buring JE, Hennekens CH.  Coffee and tea intake and the risk of myocardial infarction.  Am J Epidemiol. 1999;149:162-7.
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11. Eng Qy, Thanikachalam PV, Ramamurthy S. Molecular understanding of epigallocatechin gallate (EGCG) in cardiovascular and metabolic diseases. J Ethnopharmacol 2017; 210:296-310.
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17. Hursel R, Viechtbauer W, Dulloo AG et al. The effects of catechin rich teas and caffeine on energy expenditure and fat oxidation: a meta-analysis. Obes Rev. 2011 Jul;12(7):e573-81.
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Tea Consumption Tied to Longer, Healthier Lives Effects were most robust for green tea and for long-term drinkers. Researchers in China found an association between drinking tea at least three times a week and a longer and healthier life, according to a study published in the European Journal of Preventive Cardiology, a journal of the European Society of Cardiology (ESC). “Habitual tea consumption is associated with lower risks of cardiovascular disease and all-cause death,” said first author Dr. Xinyan Wang, Chinese Academy of Medical Sciences, Beijing, China. “The favorable health effects are the most robust for green tea and for long-term habitual tea drinkers.” The analysis included 100,902 participants of the China-PAR project with no history of heart attack, stroke, or cancer. Participants were classified into two groups: habitual tea drinkers (three or more times a week) and never or non-habitual tea drinkers (less than three times a week) and followed-up for a median of 7.3 years. Habitual tea consumption was associated with more healthy years of life and longer life expectancy. For example, the analyses estimated that 50-year-old habitual tea drinkers would develop coronary heart disease and stroke 1.41 years later and live 1.26 years longer than those who never or seldom drank tea. Compared with never or non-habitual tea drinkers, habitual tea consumers had a 20% lower risk of incident heart disease and stroke, 22% lower risk of fatal heart disease and stroke, and 15% decreased risk of all-cause death. The potential influence of changes in tea drinking behavior were analyzed in a subset of 14,081 participants with assessments at two time points. The average duration between the two surveys was 8.2 years, and the median follow-up after the second survey was 5.3 years. Habitual tea drinkers who maintained their habit in both surveys had a 39% lower risk of incident heart disease and stroke, 56% lower risk of fatal heart disease and stroke, and 29% decreased risk of all-cause death compared to consistent never or non-habitual tea drinkers. “The protective effects of tea were most pronounced among the consistent habitual tea drinking group,” said senior author Dr. Dongfeng Gu, Chinese Academy of Medical Sciences. “Mechanism studies have suggested that the main bioactive compounds in tea, namely polyphenols, are not stored in the body long-term. Thus, frequent tea intake over an extended period may be necessary for the cardioprotective effect.” In a subanalysis by type of tea, drinking green tea was linked with approximately 25% lower risks for incident heart disease and stroke, fatal heart disease and stroke, and all-cause death. However, no significant associations were observed for black tea. Gu noted that a preference for green tea is unique to East Asia. “In our study population, 49% of habitual tea drinkers consumed green tea most frequently, while only 8% preferred black tea. The small proportion of habitual black tea drinkers might make it more difficult to observe robust associations, but our findings hint at a differential effect between tea types.” Two factors may be at play. First, green tea is a rich source of polyphenols which protect against cardiovascular disease and its risk factors, including high blood pressure and dyslipidemia. Black tea is fully fermented and during this process polyphenols are oxidized into pigments and may lose their antioxidant effects. Second, black tea is often served with milk, which previous research has shown may counteract the favorable health effects of tea on vascular function. Gender-specific analyses showed that the protective effects of habitual tea consumption were pronounced and robust across different outcomes for men, but only modest for women. “One reason might be that 48% of men were habitual tea consumers compared to just 20% of women,” said Wang. “Secondly, women had much lower incidence of, and mortality from, heart disease and stroke.”