Tea vs. Coffee: Exploring Health Benefits and Cultural Significance

Tea, originating in China, is renowned for its health benefits. Research shows that tea is packed with antioxidants like catechins and flavonoids, which help reduce the risk of chronic diseases. It is especially valued for its ability to combat fatigue and improve mental clarity, thanks to its moderate caffeine levels and the presence of L-theanine, an amino acid that promotes relaxation without causing drowsiness. In Asia and Europe, tea drinking is a deeply rooted social tradition that showcases cultural heritage.

In contrast, coffee is celebrated for its ability to provide a quick energy boost. The caffeine in coffee serves as a potent stimulant that enhances cognitive function, improves focus, and increases alertness, making it a preferred drink in workplaces where maintaining productivity is crucial. Coffee is also linked to various health benefits, including a reduced risk of Parkinson's disease, Alzheimer's disease, and certain cancers. For those who wish to avoid caffeine, decaffeinated coffee offers the same rich flavor without the stimulating effects.

Coffee is particularly popular in the United States, where it is an essential part of daily life. The rise of coffee culture, marked by specialty cafes and artisanal brews, has made coffee a global phenomenon. Countries like Italy and Brazil, with their rich coffee traditions, further underscore coffee's international appeal.

In conclusion, both tea and coffee offer unique benefits and hold significant cultural importance. Tea is cherished for its medicinal properties and its role in social rituals, making it a beloved beverage in many parts of the world. Coffee, with its stimulating effects and health advantages, has garnered a loyal following, particularly in professional environments. The preference for tea or coffee often hinges on personal taste and cultural background. Both beverages continue to play vital roles in our daily lives and social interactions.
Tea vs. Coffee: Exploring Health Benefits and Cultural Significance

Why Tea Outshines Coffee: Health Benefits and Lifestyle Appeal

The debate over whether tea is better than coffee largely comes down to personal preference, yet tea boasts several distinct advantages that contribute to its popularity among many drinkers. One of the primary benefits of tea is its lower caffeine content compared to coffee. Typically, an 8-ounce cup of brewed tea contains about 30-50 mg of caffeine, while coffee can have upwards of 95 mg per cup. This lower caffeine level makes tea a gentler option for individuals sensitive to caffeine or those aiming to decrease their intake. The moderate caffeine in tea can provide a mild energy boost without the jitters or crashes commonly associated with coffee consumption.

Furthermore, tea is rich in antioxidants, particularly catechins and flavonoids. These compounds have been linked to various health benefits, including the reduction of oxidative stress, inflammation, and enhanced cardiovascular health. Green tea, known for its high antioxidant levels, has garnered significant attention in recent years for its potential to improve metabolism and support weight management. Studies published in the Journal of Nutrition have shown that green tea may aid in fat oxidation and improve insulin sensitivity, making it a popular choice for those looking to maintain a healthy weight.

Tea also contains L-theanine, an amino acid that promotes relaxation and reduces stress without causing drowsiness. This unique combination of caffeine and L-theanine can enhance mental clarity and focus, making tea an excellent choice for individuals seeking a balanced and calming beverage, particularly during stressful situations.

Moreover, tea offers a remarkable variety of flavors and types—from black and green to herbal and oolong—ensuring there is something for every palate. The versatility and numerous health benefits of tea make it a beloved beverage worldwide, with consumption trends indicating a growing preference for tea over coffee in various regions. This shift highlights tea's appeal not just as a beverage but as a lifestyle choice that supports well-being and relaxation.
Why Tea Outshines Coffee: Health Benefits and Lifestyle Appeal

Tea: A Timeless Elixir for Health and Longevity

For years, studies in China and Japan have demonstrated that the folklore surrounding tea's health benefits holds some truth -- it indeed promotes longevity. Tea, especially green tea, has been associated with various health benefits, including cancer prevention and reduced risk of cardiovascular diseases.

In Japan, the link between tea consumption and lower cancer rates is particularly evident. Japanese smokers have only half the lung cancer rate as American smokers. Additionally, in regions of Japan where tea consumption is highest, the incidence of stomach cancer is notably low. A study involving 6,000 Japanese women found that those who drank five or more cups of green tea daily reduced their risk of strokes by 50 percent.

Drinking tea with meals is a common practice in Japan and China, and it is believed to be a significant factor contributing to the low cancer rates in these countries. This practice is not limited to green tea; black tea, which is more commonly consumed in America and Europe, has also been shown to have health benefits. A study of 552 Dutch men revealed that long-term consumption of black tea and other flavonoid-rich foods, such as apples, was associated with a significantly lower risk of stroke. Men who drank more than 4.7 cups of tea a day had a 69 percent reduced risk of stroke compared to those who drank less than 2.6 cups a day.

Flavonoids, natural vitamin-like compounds found in tea, play a crucial role in these health benefits. They make blood cells called platelets less prone to clotting and act as antioxidants, countering the artery-damaging potential of highly reactive free radical chemicals. This antioxidant property is one of the key reasons why tea is beneficial in reducing the risk of cardiovascular diseases and certain types of cancer.

Tea also contributes to oral health. It contains a substantial amount of fluoride, which helps prevent tooth decay, and it works more effectively than the antibiotic tetracycline in fighting oral bacteria. Researchers at the Tokyo Dental College have found that tea combats bacteria in the mouth that cause gum disease and tooth loss. It also kills Streptococcus mutans, the primary bacteria responsible for cavities.

In addition to its benefits for oral health, tea has potential as a preventive measure against skin cancer. Researchers in Australia discovered that mice that consumed black tea experienced 54 percent fewer cancers than those that drank water, even when both sets of animals were exposed to levels of ultraviolet rays equivalent to what an average Australian receives. Earlier studies on black tea have indicated that it can be effective against some forms of cancer and may help prevent heart and liver disease.

The antioxidants in green and black tea are thought to be active agents against skin cancer. Over the past 10 to 15 years, research has increasingly shown that foods and vitamins with strong antioxidant effects may reduce the risk of many diseases, including cancer and aging. Human trials using black tea as a preventative measure against skin cancer began in Australia in 1997, further highlighting the potential of tea in promoting health and longevity.

In conclusion, both scientific research and traditional wisdom converge on the numerous health benefits of tea. Whether it's green tea or black tea, the compounds within these beverages offer significant protective effects against various diseases, making tea a valuable addition to a healthy lifestyle.
Tea: A Timeless Elixir for Health and Longevity

Caffeine in Tea

Caffeine, present among flavor compounds in tea, is antimycotic as well as antibacterial. Inhibition of growth of several mycotoxigenic Aspergillus and penicillium spp at concentrations as low as 1microgram ml has been documented. Production of aflatoxin A, sterigmatocystin, citrinin and patulin by moulds is adversely affected by caffeine. 

The mode of action of caffeine on metabolic functions of fungal cells has not been clearly defined. There was reported that caffeine, but not theophylline or papaverine, uncoupled the regulation of glycolysis and glucogenesis. 

Inhibition of growth of A.parasiticus by caffeine is due in part to an alteration in purine metabolism, but inhibition of aflatoxin synthesis does not apparently involve an inhibition of cyclic adenosine monophosphate (AMP) phosphodiesterase or a chelation of key metal ion. 

Evidence does suggest that caffeine may restrict glucose uptake by A.parasiticus, resulting in decreased aflatoxin production. A preliminary examination of the affect of caffeine on patulin production by penicillium suggests that activity does not involve a generalized inhibition of lipid synthesis.

Caffeine in Tea

Suitable climate for tea cultivation

Tea is one of the most important cash crops worldwide, playing a significant role in rural development, poverty reduction and food security in developing countries. The cultivation of tea requires strictly defined climatic and soil conditions.

Tea plant is an evergreen bush that flourishes in tropical, subtropical and temperate regions at elevations below 3000 m. Tea does not tolerate long droughts or frost and extreme heat. The best quality tea is produced at high altitudes of 1500 to 2250 meters above sea level.

Camellia sinensis var. sinensis grows in cooler mountainous regions, while Camellia sinensis var. assamica grows best in a tropical climate.

Tea grows in a wide range of latitudes of between 30◦ S and 42◦ N that satisfy the certain eco-physiological requirements of tea plants, including thresholds of climatic variables.

Tea requires rainfall of 1200mm to 2200mm that is well distributed throughout the year, and relative humidity of around 80 % (never less than 40%).

Tea is considered optimal conditions are annual precipitation at the level of 2500 - 3000 mm3 per square meter.

Tea plants can survive a wide range of temperatures between 10 to 30 ◦C. Solar radiation is another primary driver which plays a significant role in photosynthesis in plants. Excessive wind causes water deficit in tea plants due to high evapotranspiration.

The monsoonal climate, alternate wet and dry seasons and the high elevation of subtropical mountains in China, India, and Sri Lanka appear to provide above optimal conditions for tea cultivation.

Unfavorable conditions, such as droughts, floods, frosts or excessive heat, limit plant growth and lead to changes in the biochemical structure of the raw material which lead to a decrease in its quality.
Suitable climate for tea cultivation

Major health benefits of tea

“Tea” is referred to the aromatic beverage prepared by incubating cured leaves of the plant Camellia sinensis with hot or boiling water.

The benefits of tea drinking in both aspects of mental and physical health have been discussed for thousands of years in China and many other countries where the tea is consumed.

Several research investigations, epidemiological studies, and meta-analyses suggest that tea and its bioactive polyphenolic constituents have numerous beneficial effects on health, including the prevention of many diseases such as cancer, diabetes, arthritis, cardiovascular disease, stroke, genital warts and obesity.

Ten major health benefits of tea including:

• Tea may prevent cancer
• Tea may restrict blood cholesterol
• Tea may control high blood pressure
• Tea may lower blood sugar
• Tea may suppress aging
• Tea refreshes the body
• Tea may deter food poisoning
• Tea may prevent and treat skin disease
• Tea may stop cavities
• Tea may fight virus
Major health benefits of tea

Tea and thermogenesis

Obesity is increasingly recognized as public health burden, because it is associated with an increased risk for many diseases, including the metabolic syndrome, i.e., hypertension, insulin resistance or type 2 diabetes mellitus, arteriosclerosis and coronary heart disease

All teas contain high quantities of several polyphenolic components such as epicatechin, epicatechin gallate, epigallocatechin and, the most abundant and probably the most pharmacologically active, epigallocatechin gallate.

EGCG (Epigallocatechin-3-Gallate), the most abundant catechin in green tea, representing approximately 35% of total catechins, has received the most attention as a potential anti-obesigenic agent. Long term treatment (12 wks) with green tea extract containing 115 mg EGCG daily significantly reduced body fat (7%), body weight (2%), and BMI (2%) in men and women.

Possible mechanisms include:
1) decreasing digestive activity,
2) increasing lipolytic activity,
3) decreasing lipogenic activity,
4) increasing fat oxidation and thermogenesis,
5) modulation of the activity and expression of lipoprotein lipase,
6) decreasing the cell number and size of adipocytes, and
7) decreasing hormone-stimulated proliferation of preadipocytes and their differentiation to adipocytes.

From caffeine, that is also present in green tea, it has been reported that it has thermogenic effects and can stimulate fat oxidation in vitro, in part through sympathetic activation of the central nervous system.

Daily increases in thermogenesis of approximately 300–400 kJ can eventually lead to substantial weight loss. The sympathetic nervous system is involved in the regulation of lipolysis, and the sympathetic innervation of white adipose tissue may have an important role in the regulation of total body fat in general.

Fat oxidation is mainly under the control of the sympathetic nervous system (SNS). Therefore, there are a number of approaches to increase SNS activity either directly (by -adrenergic agonists) or indirectly (by norepinephrine releasers and reuptake inhibitors). Interestingly, a number of compounds extracted from plants such as caffeine from coffee and tea, ephedrine from ephedra, and capsaicin from pungent spices can modulate catecholamine release and activity. The main catecholamines are epinephrine (adrenaline), norepinephrine (noradrenaline), and dopamine.

Caffeine also affects the thermogenesis by inhibiting the enzyme phosphodiesterase. This enzyme degrades intracellular cyclic amino mono phosphate.51 Phosphodiesterase usually hydrolyses cyclic adenosine monophosphate (cAMP) to AMP, but after consumption of caffeine, cAMP concentration rises and SNS activity will be increased and inactive hormone-sensitive lipase will be activated, which promotes lipolysis.
Tea and thermogenesis

Spiced tea

Spice tea is made from spice and water. Cardamom, cinnamon, cloves, ginger, tulsi leaves and pepper are among the most popular spices for this.

While spiced tea is made by brewing specie tea then added tea-leaves (the leaves of Camellia sinensis) and brewing for a bit longer.

Spice tea is a staple in India, consumed by millions throughout the day.  The spread of spiced tea to the rest of the world has been variations on recipes, and often soy, rice or non-dairy milks are added. Green or rooibos tea leaves are used, instead of black, to reduce caffeine levels.
Spiced tea 

History of tea in America

Tea came to America in 1650, even before it reached England.  Peter Stuyvesant brought the first tea to America to the colonists in the Dutch settlement of New Amsterdam, which later became New York.

Soon American colonists were consuming more tea than England and the Dutch stayed active in tea trade throughout the Western world.

Once tea did become popular in England, the British could hardly be expected to travel abroad without their precious drink and as a result, tea made second entree to the United States with the British colonists.

By the beginning of the 18th century tea was available in major American cities, but through trade with England. In 1880’s, America came to the forefront as the biggest importer of tea due to faster clipper ships and the ability to pay its debts in gold.

In 1890, Sir Thomas Lipton, who had already helped to popularize tea in England, brought his business acumen to the United States. During the war years, Lipton had enlarged its U.S. sales and in August 1919 it moved its packing plant and main office to a large eleven-story building in Hoboken, New Jersey.

Another British form, Tetley Tea, had sizeable American market share. Salada Tea Company founded in Toronto in 1892 also marketed in the United States.

At the turn of the 20th century the tea bag came along a surprise and Thomas J. Lipton was responsible for designing a four sided tea he dubbed the ‘flo-thru’ tea bag.
History of tea in America

What is biotea?

The production of organic tea or biotea represents a return to earlier environmentally friendly methods free from chemical additives - the emphasis is on biodiversity and conservation.

In 1980 the German company of Schraders in Bremen, launched it first biotea on the market. It was not until the autumn of 1989 that organic tea first appeared on the market on the UK from the first commercial organic tea estate in the world.

In organic farming, workers are not subjected to the chemical pesticides and fertilizers that damage health as they are sprayed on the crops. Instead, animal manure, compost, organic matter, and ground cover are used to add nutrients to the soils.
What is biotea?

History of tea in Sri Lanka

Tea plants did not figure among the local flora in the island of Sri Lanka, until the early nineteenth century when several entrepreneurs used their estates as test plots.

Tea was introduced by British when tea estates were laid out and first managed by the large tea companies who exported their produce to consuming countries.

Tea brush was introduced to Sri Lanka as early as in 1828. Maurice de Worms of Rothschild Estate was the first to put the tea bush to commercial use in Sri Lanka.

He planted a clearing at Labookellie with Chinese tea, but the venture turned out to be a financial failure due to the high production cost and the inferior quality of the product.

In 1839, Dr Wallich, head of the botanical garden in Calcutta sent several Assam tea plant seeds to Peradeniya estates near Kandy.

Usually the credit for introducing the cultivation of tea to the island is given to James Taylor, who planted tea of the Assamese variety on Loolecondera state in 1867. James Taylor, a Scottish using tea seeds supplied by Peradeniya nursery for first cultivation.

Taylor then set up the first tea ‘factory’ on the island. The tea produced was a success which later was sold locally at Rs 1.5 per Lb.

The first consignment of Ceylonese tea was sent abroad in 1873. Tea cultivation nevertheless remained a minor activity for 20 years.

In 1970, the production came under the control of the Sri Lankan government’s Estate Development Board and tea was sold at tea auctions in Colombo to the distributing companies.
History of tea in Sri Lanka

Keemun tea the Burgundy of teas

The classic English Breakfast Tea comes from Keemun. This is a mild black tea that grows in aromatic orchards in the Anhui and Jiangxi provinces. It is one of the highest quality of Chinese black tea.

Keemun tea is rich in minerals, which give it a unique color, flavor and aroma. The aroma tea has a rosy and woody note.

Keemun tea can be drunk to relieve fever and as a preventive to cancer. Keemun, a black Chinese tea with a fruity taste and had a hint of pine.

The mild, sweet infusion it brews makes it a pleasant tea to have almost anytime. Because of its strong body, it can be enjoyed with milk and sugar or lemon.

It also pairs well with lightly spiced foods or can be savored by itself at the end of a meal. Keemun possess a full, concentrated flavor and a toasty aroma and sometimes referred to as the ‘Burgundy of teas.’

Today a good Keemun is recognized as one of the truly classics black tea in the world. It is a great self-drinker but it’s often used in black tea blends.
Keemun tea the Burgundy of teas

Protective Effects of Tea on Cardiovascular Disorders

Tea beverages derived from infusions of Camellia sinensis are consumed daily by millions of people globally. 

Nowadays green and black teas are beverages prepared by infusing the dried leaves of Camellia sinensis in hot water to achieve a desirable taste profile.

The physiological effects of the prevention and tea products on the cardiovascular system and their potential uses for the prevention and treatment of cardiovascular disorder have drawn a great deal of interest. 

Cardiovascular disease is a major cause of morbidity and mortality in all regions of the world. The disease takes the lives of almost one million Americans each year, more than any other disease.

In traditional Chinese medicine, tea, especially green tea, can be used as a major component in a composed prescription for treatment of hypertension or coronary heart diseases.

Epidemiological experimental investigations on the effects of tea on cardiovascular disorders have been concentrated mainly on the effects on blood pressure, on blood lipids and on atherosclerosis. Many studies clearly indicated a decrease risk of cardiovascular disease with higher tea consumption.

Tea polyphenols, known as catechins, usually account for 30-42% of the dry weight of the solids in brewed green tea. Catechins can increase the antioxidants capacity to human plasma, which could help reduce cardiovascular disease.

According to the scientists from the University of Oslo, approximately 20,000 middle-aged Norwegian men and women, cholesterol levels decrease as black tea consumption increases.

Men drinking five or more cups of tea daily had total cholesterol level 9.3 mgs per deciliter lower than those drinking one cup or less daily, and women had levels 5.8 mgs per deciliter lower.
Tea consumption and effects on cardiovascular disease

Drainage system in tea plantation

A good surface drainage system is important, particularly on low lying heavy soils to allow timely access to fields for harvesting and other operations following periods of heavy rainfall or flooding.

Tea plant is susceptible to stagnant water. The plant cannot survive in an area where water logging is a perpetual feature.  It should be avoided with an adequate drainage system can be constructed.

There is contour drainage system on tillah land according to soil condition. In flat land, straight rectangular drainage system is maintained.

On sites where major drainage work and leveling is required, preparation should begin up to one year before the anticipated transplanting time.

Although in certain tea area, rainfall may exceed potential evapotranspiration for limited period, effective moisture conservation measures are needed to tide over the frequently occurring drought stress periods within the growing season.

Irrigation is therefore best perceived as a system by which a quantum of water is added during the stress period to bring back the soil moisture level to its optimum.
Drainage system in tea plantation

Good quality of tea

The quality of tea is the summation of the desirable attributes comprising internal and external things like aroma, flavor, strength, color and briskness.

Some high quality teas are perceived to be bitter in the mouth and sweet in the throat. For other high quality teas, bitter and astringent have negative connotations with aromatic, sweet and delicate are desired characteristics.

The quality of tea varies from garden to garden. Although the qualities of second flush it is still the best quality. This means good quality tea should be able to give several infusions from the same leaves.

The good quality tea also once adding with water, it will quickly sink to the bottom of the cup.

Gold tip or tippy eta leaves are considered to be of good quality. Hand-rolled tea leaves have a better tip than machine rolled ones.

The factors affecting the quality of include:
*Polyphenol and the enzyme content in tea leaves.
*The finest tea is from higher elevations of 900-2100 meters. Many high quality tea plants are cultivated at elevations of up to 1500 meters.
*Soil
*Processing technique

In general tea in bags is not of as good a quality as loose tea. But many of the better tea companies are combining the quality of loose tea with the ease and convenience of a tea bag with great success.
Good quality of tea

Pruning of tea plant

The essence of pruning system is to maintain an optimum amount of tree so that, the plants remain in a steady state of productivity.

The system is determined from the balance of growth of the plants in relation to their productivity, particularly potential or expected levels of yield.

As a wild plant, the tea tree can grow to twenty-five feet and its transformation into a waist-high bush is a result of four year cycles of pruning and plucking.

Careful, attention is paid to each individual plant and every cutting is placed by hand, light work that is often done by elderly and ill women and small children. Tea bushes are required to be pruned at regular intervals, the time period between two consecutive prunings is known as pruning cycle.

As the plant grows, careful pruning determines its heights. The plant’s center stem is cut at six to eight inches after eighteenth months, stopping the growth of that stem, and promoting lateral branching.

How frequently a plant requires pruning depends on its growth, shape, site, weather, and the reason for pruning.

Plants in warm winter climates and plants that grow quickly generally need more frequent pruning than slow-growing plants in cold regions.

The running cycle of seedling tea can be two, three or four years corresponding to low-country, mid country and upcountry. Pruning cycle of vegetatively propagated tea is three, four and five years for low country, md country and up country.
Pruning of tea plant

History of tea nomenclature

Tea first arrived in Europe in 1610, after chocolate in 1528, but before coffee in 1615.

In 1690, E. Kaempfer, a German medical doctor cum botanist who came to Japan from Holland and observed the habit of tea drinking among the people, named the bush ‘thea’.

Nomenclaturist Carl Linnaeus published his Species Plantarum (1753). He took the original Amoy pronunciation (Tay), and applying the country of discovery to his two part naming system (genera and species, he came up with Thea sinensis.

Subsequently, he names the two varieties Thea viridis and Thea bohea.

In 1818, Robert Sweet, an English botanist, united Theus and Camellia into one genus and called it Camellia, as it is still called today.

The name Camellia came from a Moravian Jesuit named George Josheph Kamel (1661-1706), who studied Asian plants. In 1688, George Josheph Kamel went to Luzon, in the Philippines, where he studied botany, even though he was sent as a priest. He had his paper published in The Philosophical Transactions of the Royal Society.

The species name, sinensis, means ‘from China’. Interestingly enough, over 2000 varieties of tea are derived from this one plant species.

It wasn’t until 1959 that the International Code of Nomenclature named the tea plant Camellia sinensis.
History of tea nomenclature

Aroma of tea

The custom of drinking tea has spread all over the world. The aroma is the major factor contributing to tea quality and enjoyment.

The freshly picked green leaves of the tea plant require processing in order to induce the formation of the characteristic odor and flavor of tea. Various aroma compounds develop during withering and fermentation stages of tea leaves.

The formation of tea aroma during the four main stages of manufacturing: beginning with fresh green leaf stage through the withering stage, fermenting stage after rolling, and finally in the made tea stage flowing firing.

Floral tea aroma compounds are known to be generated during the fermentation process in the tea manufacturing and is one of the most important factors to determine the quality of each tea type, especially oolong and black tea.

Research into characterizing tea aromas has been carried out for past 100 years, and more than 600 volatile compounds had been reported or isolated.

The most important of these are: limonene, phenylethyl alcohol, linalool, geraniol, trans-2-hexenal, phenylethyl acethyldehyde, alpha and beta-ionone, isovaleric acid, benzoic acid, o-cresol, dimethyl disulfide and n-ethylformyl pyrrole together with 18 esters and lactones.
Aroma of tea

Effects of Tea on Cardiovascular Disorders

Effects of Tea on Cardiovascular Disorders
The physiological effects of the prevention and tea products on the cardiovascular system and their potential uses doe the prevention and treatment of cardiovascular disorder have drawn a great deal of interest.

In traditional Chinese medicine, tea, especially green tea, can be used as a major component in a composed prescription for treatment of hypertension or coronary heart diseases.

Epidemiological experimental investigations on the effects of tea on cardiovascular disorders have been concentrated mainly on the effects on blood pressure, on blood lipids and on atherosclerosis.
Effects of Tea on Cardiovascular Disorders

Relationship between tea drinking and Alzheimer’s disease

A steaming cup of black tea or green tea, the comforting drink of choice for millions of people around the word, may also help to treat or prevent Alzheimer’s disease.

Alzheimer’s disease is a type of dementia in which parts of the brain atrophy and cease to function.

The nerve cells concerned with memory are located in the base part of the forebrain. In the brain of Alzheimer’s disease patients, the nerve cells lose their functions, and the functions of these cells thought to be good way of treating Alzheimer’s disease.

The study shows that a component in tea, teannin was found to stimulate the synthesis of this growth factor.

Laboratory test found that regular consumption of green or black tea inhibits the activity of certain enzymes in the brain that are implicated in the development of Alzheimer’s disease.

The findings in the lab experiment showing that compounds in green tea may protect brain cells from damaging processes that mark dementia conditions like Alzheimer’s disease.

In China and Japan, aging doesn’t seem to mean inevitable cognitive decline and when it does occur it is often less severe than the syndrome seen in the west. There is evidence that green tea may actually ward off Alzheimer’s disease and other forms of mental degeneration.
Relationship between tea drinking and Alzheimer’s disease