My day begins with copious quantities of freshly brewed tea. This ritual used to be a guilty pleasure, but now that tea has been promoted to health superstar, I now drink my morning cuppa(s) with pride.
Tea and antioxidants
Tea is one of the largest sources of antioxidants in our diet. It is particularly rich in a type of antioxidant known as phenols. One particular phenol, epigallocatechin gallate, is a whopping 30 times more potent than vitamin E. There are a variety of other phenols in tea including; catechins, theaflavins, and gallic acid. Each compound has been studied extensively, with varying roles in health maintenance and disease prevention. Overall, the benefits of these antioxidants are helpful for heart disease, diabetes, eye disease, cancer and the signs and effects of aging, including wrinkles. Comparisons between tea and red wine (another antioxidant rich beverage), show that tea has more antioxidant activity….. and you can still drive home!
Tea and Stress
A cup of tea and a good lie down (and a stiff scotch) is a time honoured tradition for coping with a tough day. It’s not just a state of mind, studies show that people are less stressed after drinking a cup of tea. Theanine (the antioxidant) has been shown to decrease levels of cortisol, the stress hormone.
Tea and caffeine
Tea contains small amounts of caffeine. This applies to green as well as black tea. However, the amount of caffeine is less than half that of a cup of coffee. Small amounts of caffeine can be good, increasing stamina, concentration and mental acuity. So, drink tea if you are studying or working on a project. However, if you are very caffeine sensitive, dip your teabag in some boiling water for 5 seconds, discard this water, and your second brew will be caffeine free, as most caffeine is released in the first few seconds.
Tea and Iron absorption
One downside to drinking tea is that it may reduce the absorption of iron from our food. However, it is only non-haem or vegetable –source iron (e.g. from spinach) that is reduced, iron absorption from meat (haem iron) is not affected. If you are at risk of low iron (anaemia) avoid drinking tea for half an hour before, and one hour after meals. If you want to maximize iron absorption from your food - take a vitamin C supplement, squeeze some lemon juice over food, or drink a glass of vitamin C rich juice such as guava, tomato or orange juice with your meal.
Black Tea, Green Tea….which TEA?
There is often confusion as to which tea is the best tea. Simply, all tea whether black, oolong, green or white, come from the same plant – Camelia sinensis. They have just been picked or processed differently. Black has been dried and fermented the longest, white the least. The traditional processing of teas creates a slightly different range of antioxidants for each variety. Green tea has been the most extensively studied, and as a result sports the most health claims, however black and oolong tea are also very good sources of antioxidants and other health promoting substances…the studies will come in on their behalf.
Tea and Milk
Recent media reports have suggested that adding milk to tea reduces its health giving properties. However, this does not seem to be the case. Many studies since have shown that lkadding a little milk does not change the availability of antioxidants in the bloodstream. The stronger the tea, or longer it has been steeped will increase the antioxidant availability, milk or no milk.
Fluid
We need about 2 litres of fluid daily for good health. US and Australian health authorities now recommend drinking tea, in addition to water, as a healthy way to make up our fluid requirements. Formerly, it was thought that tea was a diuretic, that is we would urinate as much or more fluid than ingested; however, this has since been proven to be incorrect. Cheers!
Tea and teeth
Tea contains high levels of naturally occurring fluoride. Fluoride hardens and protects teeth from decay. Tea also contains antibacterial substances that reduce the incidence acid producing bacteria that cause cavities.
If, like me, you cannot start the day without a strong cuppa, we can now feel smug about it.
References
Kyle JA, at al (2007) Effects of Infusion Time and Addition of Milk on Content and Absorption of Polyphenols from Black Tea. J Agr Food Chem; May 10 (epub ahead of print)
OK Chun, et al (2007) Estimated Dietary Flavonoid Intake and Major Food Sources of US Adults. J. Nutr 137:1244-1252
Steptoe A, et al (2007) The effects of tea on psychophysiological stress responsivity and post-stress recovery: A randomised double-blind trial. Psychopharmacology (Berl). 2007 Jan;190(1):81-9.
Ito K, Nagato Y, Aoi N, et al. (1998) Effects of L theanine on the release of alpha-brain waves inhuman volunteers. Nippon Nogeikagaku Kaishi 72:153-157.
Kenta Kimura, et al (2007) L-Theanine reduces psychological and physiological stress responses. Biol. Psychol:74(1):39-45
