Thursday January 10, 2013 | 1 comment
Every year, as the calendar page turns, a bright, shiny New Year arrives and along with it comes a plethora of online, magazine, and newspaper articles on how to improve your health and lose weight in the coming year. Culturally, we go from holiday gastronomic indulgence to cleanses and detoxing in just seven days. One of the essentials in many of these healthy new regimes is green tea. For tea lovers who enjoy tea all year round, it’s a nice pat on the back to acknowledge that something we enjoy so much is highlighted as a feel-good food. The only question becomes: How “good” is tea? While the science is there to demonstrate the healthy properties of tea, even though at times the studies can be contradictory, tea companies are limited in what they can say about these health benefits by the FDA. The information about green tea either gets inflated or minimized, depending on the context. In the spirit of the unofficial Green Tea Month, let’s review which healthy components make up the tea leaf:
Antioxidants – An umbrella term that includes the specific compounds polyphenols, flavonoids, flavonols, and catechins. Polyphenols act as antioxidants and contribute to the taste and appearance of teas. Flavonols are a subset of flavonoids, the most prevalent one in tea being catechins, which make up around 25% of the tea leaf by dry weight. The less oxidized the tea, the higher the level of catechins (green and white teas have much higher levels than black teas, which may account for some of the contradictions between studies in countries where green tea is most popular versus studies conducted in black tea-drinking countries). The most common catechin, frequently highlighted on tea packaging, is EGCG (epigallocatechin gallate).
A recent review of research studies found evidence that catechins can improve blood vessel health, protect against plaque buildup in arteries, and promote anti-diabetic effects in insulin resistance. Catechins are as much as 100 times more potent as an antioxidant than Vitamin C and 25 times more potent than Vitamin E.
Caffeine – An alkaloid that stimulates the nervous system in the human body, resulting in increased alertness. Along with caffeine, tea contains lower levels of the mild stimulants theobromine and theophylline. At lower levels than coffee, these compounds give tea the customary lift or wakefulness property and also contribute to the flavor profile of tea.
Amino Acids – Few in number, amino acids only comprise about 1% of tea leaves (dry weight), with theanine making up about 50% of the total. Theanine contributes to the aroma and taste of teas, green tea in particular.
Vitamins – Tea contains very small amounts of Vitamin B6, riboflavin, thiamin, niacinamide, pantothenate, and carotenes. Their nutritional contribution is minimal.
Minerals – By dry-weight, tea leaves contain approximately 5% minerals, the most prevalent being potassium, along with magnesium, manganese, phosphorous, copper, and aluminum. Tea also contains significant levels of fluoride.
Volatile Compounds – Present in low levels, aldehydes, alcohols, sulfides, and other compounds have a significant influence on tea quality and taste. Their levels are a function of the terroir of the tea (growing conditions, climate, leaf processing, and storage).
If weight loss is a goal, the other healthy benefit of green tea is that it tastes great and usually is drunk without adding sugar, making it a zero-calorie beverage. In fact, due to the components of the leaf, it can help burn off about 25 calories per cup. Maybe for all of these reasons, the lobbying arm of the Specialty Tea Institute should look into officially designating January as Green Tea Month in years to come. One cup at a time, green tea is a great start to 2013.