The Benefits of Tea

Tea is the most commonly consumed beverage in the world after water. Among all varieties of tea - black, green, white, oolong, red, herbal - which one offers the most health benefits? (HealthCastle.com)

Benefits of Tea

Many different studies have shown the superior and anti-cancer properties of antioxidant polyphenols. Some studies have suggested that tea's polyphenols may greatly reduce the risk of gastric, esophageal and skin cancers, ibaesd on if someone can consume 4 to 6 cups daily. In another study, it was shown that just 2 cups of tea may lower the risk of ovarian cancer by 46 percent in women. Other studies have found that polyphenols help prevent blood clotting and lower cholesterol levels. One Japanese study found that green tea lowers death rates from heart disease.

Tea: Black, Green, White or Oolong?

Black, green, white, and oolong teas derive their leaves from a warm-weather evergreen tree known as Camellia sinensis. The leaves from this tree contain polyphenols. The more processing tea leaves undergo, the darker they will turn. Green tea and white tea are the least processed tea. They are simply steamed quickly. According to Dr. Doug Balentine, Director of Nutrition Health with Lipton, white tea is derived from the young new leaves from the Camellia plant in early spring. These young leaves contain no chlorophyll, so they are silvery white. Black and oolong teas are partially dried, crushed and fermented. As we have mentioned before, regardless of the processing method, black, green, white and oolong teas all contain polyphenols. In fact, tea ranks as high as or higher than many fruits and vegetables in the ORAC score, a score that measures antioxidant potential of plant-based foods.

What about Herbal Tea and Red Rooibos Tea?

Herbal tea is not derived from the leaves of the Camellia plant and so does not have the particular health-promoting properties. Indeed, most herbal teas in the market are NOT tea at all. They are only infusions made with herbs, flowers, roots, spices or other parts of some plants. The proper term for this type of beverage is "tisane."

The recently popular South African red Rooibos tea also falls within the herbal tea or tisane category. "Red Rooibos tea is not really tea as it is not derived from the Camellia plant," Dr. Balentine said. They may not contain the same beneficial flavonoid compounds as found in black and green teas. In fact, Dr. Balentine said that "no scientific evidence yet has shown the health benefits of red Rooibos tea."

Although tisane does not contain as any polyphenols, it does promote other various health qualities such as relaxation and calming effects.

Theanine: A way to a better sense of well-being! (wikipedia)

Theanine is an amino acid commonly found in tea (infusions of Camellia sinensis), and also in the basidiomycete mushroom Boletus badius.^[1] In 1950 the Tea laboratory of Kyoto successfully separated theanine from Gyokuro leaf, which has the highest theanine content among all teas. Theanine is related to glutamine, and can cross the blood-brain barrier.^[2] Because it can enter the brain, theanine has psychoactive properties.^[3] Theanine has been shown to reduce mental and physical stress^[4], may produce feelings of relaxation^[5] and improves cognition and mood when taken in combination with caffeine.^[6]

Theanine is speculated to produce these effects by increasing the level of gamma-aminobutyric acid (GABA) production. Theanine increases brain serotonin, dopamine, GABA levels and has micromolar affinities for AMPA, Kainate and NMDA receptors.^[7] It has also been found that injecting spontaneously hypertensive mice with theanine significantly lowered levels of 5-hydroxyindoles in the brain.^[8] Researchers also speculate that it may inhibit glutamic acid excitotoxicity.^[7] Theanine also promotes alpha wave production in the brain.^[3]

Studies on test rats have shown that even repeated, extremely high doses of theanine cause little to no harmful psychological or physical effects.^[9] Theanine showed neuroprotective effects in one rat study.^[10]

L-theanine may help the body's immune response to infection by boosting the disease-fighting capacity of gamma delta T cells. The study, published in 2003 by the Brigham and Women's Hospital, included a four-week trial with 11 coffee drinkers and 10 tea drinkers, who consumed 600 milliliters of coffee or black tea daily. Blood sample analysis found that the production of anti-bacterial proteins was up to five times higher in the tea-drinkers, an indicator of a stronger immune response.^[11]

Tea: Caffeine content

According to the American Dietetic Association, a cup of tea contains an average of 40 mg of caffeine, compared to 85 mg as found in a cup of freshly brewed coffee.

What about Decaf Tea?

We do not know whether decaf teas have the same polyphenols, and thus the same health benefits. It is not yet known if removing caffeine also removes polyphenols in the decaffeinating process.

The Bottom Line

Tea is a healthy beverage offering many health benefits (if you skip the cream and sugar). Brew your tea for at least 3 - 5 minutes to bring out the beneficial polyphenols. Enjoy the aroma of tea! Also beware of bottled green tea beverages, like Enviga, that claim to help lose weight! No solid scientific evidence has proven its efficacy in burning calories.