For centuries green tea has been one of the most popular beverages consumed in Japan and China. Its popularity is now rising in the west.
A 2014 article in the Washington Post reports that Americans are drinking 40% more green tea than they did in 2000. Much of this rise in consumption is due to the increasing knowledge of green tea’s numerous health benefits.
What is Green Tea?
Green tea, black tea and oolong tea are all made from the leaves of the Camellia sinensis plant, but are processed differently. To make green tea, freshly harvested leaves are immediately steamed to prevent oxidation and fermentation. This process preserves the green pigment in the leaves and many of the natural polyphenols.
Polyphenols are micronutrients that come from certain plant-based foods. Laboratory research has shown that green tea leaves contains 6 times more phenolic compounds than an equal weight of black tea leaves.
Most of the polyphenols in green tea are a type of flavonoid known as catechins. There are 6 primary catechin compounds in green tea. Of these the most abundant and most active is a powerful antioxidant called epigallocatechin gallate (EGCG). EGCG has been widely studied for its role in preventing and treating diseases.
Matcha Green Tea
Matcha is a fine powder made from Camellia sinensis leaves that are grown in shade. The low levels of sunlight cause the plants to produce more chlorophyll, turning them a deeper shade of green.
After harvesting, the stems and veins are removed from the leaves. The leaves are then dried and grounded into a powder which is whisked into hot water or milk to create a concentrated green tea beverage.
When you drink matcha, you are consuming the entire tea leaf and not just a tea infusion with strained tea leaves. This means a cup of matcha is a much richer source of catechins than a cup of brewed green tea.
One analysis found that the concentration of EGCG in matcha was at least three times higher than the highest levels found in standard green tea. The shade-growing process causes the tea plant to produce more L-theanine and caffeine, so matcha is richer in both.
L-theanine is an amino acid which has a calming, relaxing effect when consumed on its own. In tea, it appears to have a synergistic effect with caffeine, helping to promote wakefulness and attention while mitigating caffeine side-effects such as raised blood pressure.
A study published in Nutritional Neuroscience found that a combination of L-theanine and caffeine improved alertness and cognitive performance while reducing tiredness.