Its unique taste, aroma and the growing investigations of its medicinal properties confirming the age-old belief that tea drinking is healthy and has its benefits has made tea a popular beverage.
Historical facts about tea indicate that this ever-popular beverage originated in China some 5,000 years ago. Tea is prepared from the leaves of a shrub camellia sinensis. There are over 3,000 varieties of this bush grown in mountainous areas around the world.
Today tea is one of the most served beverages in the world. Black and green teas are popular versions. Drying and roasting produces green tea whereas black tea is obtained after a fermentation process. Economic and social interest in the tea is clear from the fact that about 18-20 billion tea cups are consumed daily in the world.
With a long tradition of drinking tea, Saudi Arabia boasts the second largest retail tea market in the Middle East. Although coffee is the preferred hot beverage, accounting for more than half of all hot drinks in retail value terms, according to leading global market analyst Euromonitor, tea continues to play an integral part in family and social occasions in Saudi Arabia.
The Saudi Arabian customs and traditions state that on friendly and formal meets, guests should be offered black tea as a sign of cordiality. So when tourists visit local households they should drink a cup of tea to acknowledge the hospitality. Drinking tea is a traditional habit among Saudi people. It is consumed throughout the day and at all occasions.
The 75 percent of the estimated 2.5 million metric tons of dried tea that are manufactured annually processed as black tea which is consumed by many countries. In the UK, one liter of tea, on average, is consumed per person per day.  In Iran, 1.3 kg of black tea, on an average, is consumed per person per year.
Tea is used in folk medicine for headache, digestion, diuresis, enhancement of immune defense, as an energizer and to prolong life. Tea contains flavonoids, minerals and trace elements that are essential to human health.
Current studies show that tea contains specific antioxidants and health promoting ingredients, lowering the risk of heart diseases, stroke and certain type of cancer like oral, pancreatic and prostate. Plenty of studies have suggested that tea is a boon for cardiovascular health, but new research has found that adding milk to your favorite brew negates these health benefits of tea.
The culprits in milk is a group of proteins called caseins that interact with tea, decreasing the concentration of catechin -- the flavonoids in tea that are responsible for its protective effects against heart disease, according to the study authors.
The intake of food and beverages contaminated by heavy metals is harmful to human health and several countries have imposed laws to restrict the presence of heavy metals concentration in food and beverages. The main source of trace metal intake by the shrubs is their growth media; consequently, some differences in metal contents are expected depending upon the origin.
Therefore, tea drinking could be an important source of some essential minerals such as manganese, which activates numerous enzymes. The levels of manganese in other food/beverages are relatively small. Various reports have discussed the potential health implications of some chemical factors such as heavy metals in tea, particularly since the tea bush is known to accumulate trace metals. Tea can be contaminated by heavy metals during growth period and manufacturing processes, which might increase the metal body burden in humans.
Metallic constituents of tea leaves are normally different according to the type of tea (green or black) and geological source. The main sources of heavy metals in plants are their growth media, nutrients, agro inputs and soil. Other factors may include pesticides and fertilizers.
Black tea, the most popular variety, offers a hearty flavor and deep reddish color that results from an extensive fermentation process that includes exposing crushed tea leaves to the air for a set amount of time until they are fully oxidized and dried. Black tea generally refers to tea whose leaves are heavily oxidized and fermented. It is generally stronger in flavor than other varieties of tea (such as green, white and oolong teas) and generally contains higher caffeine content. Black tea is not black when poured. The name refers to the color of the leaves, which are black. When poured, black tea has a dark amber color.
Black tea is able to preserve its flavor for several years. Its ability to maintain its flavor has meant that historically, it has been used for trading purposes. Black tea accounts for around 90 percent of all tea sold worldwide today. Black tea is a rich source of antioxidants, which have been linked with cancer prevention, decreased heart disease and lowered cholesterol.
Green tea makes up about 10 percent of world-tea production and is a milder brew with a mild, appealing taste and understandably green appearance. There is no oxidation during processing. Rather, the leaves are simply withered and then roasted or dried. To maximize the taste and benefits, it is preferable to brew tea leaves in loose form rather than using a small tea ball or infuser (yet these accessories are popular, convenient, and yield tasty brews). This allows the leaves to fully open and release their entire flavor.
Owing to great importance of minerals present in the tea, many studies have been carried out to determine their levels in tealeaves and infusions. Determination of heavy metals in tea samples is important from two aspects; to judge their nutritional value and to guard against any probable ill effects, they may cause to human health. In a recent study, 17 commercial black tea samples sold in hypermarkets of Saudi Arabia were analyzed for their heavy metal contents. Depending upon country of origin, great variability was noticed in the contents of lead, cadmium, nickel, chromium, copper and manganese. An international comparison of the results revealed that lead levels in Chinese black tea samples were twofold higher than Saudi black tea samples. However, some samples grabbed from local markets of remote areas contained higher levels of certain metals owing to poor processing and storage techniques, and artificial coloring of black tea.