I can still remember that as children we were often exhorted to eat those leafy greens and fruits for the vitamins they contain : carrots for vitamin A, oranges for vitamin C, brocolli for Vitamin E, to name a few. But hardly, if ever, was green tea vitamins ever mentioned. Quite apart from the question whether green tea is suitable for children, even today, if you search online, you will notice that green tea is not listed as a primary source of vitamins.
The meaning of green tea vitamins
It has, therefore, daunted upon me that the term green tea vitamins might be loosely used to refer to green tea antioxidants or green tea polyphenols rather than the types of vitamins contained in green tea. So if you have that meaning in mind, you may like to read my related articles in this category.
In this article the latter meaning is used and the main focus is their functions as antioxidants and how they work synergistically with the polyhenols catechins .This will be more in line with the theme of this green tea antioxidants category of this blog. Again, I must state that I am not a nutritionist and what I write is for information purposes only. You should consult your health care provider as regards your own nutritional needs.
The green tea vitamins
We have seen in my article on green tea polyphenols the emphasis placed on the polyphenols catechins, a class of flavonoids, as evidenced by their composition in green tea extracts. So, although green tea vitamins may seem somewhat sidelined in discussions about the antioxidant activities of green tea, they are by no means any less important. Being classified as either water or fat soluble, the vitamins interact synergistically not only amongst themselves but also with the polyphenol catechins which are water-soluble antioxidants.
Briefly, just to recap on what antioxidants do. They quench the free radicals which are the unstable molecules by donating that much needed electron. Free radicals are formed through a process called oxidation just like rusts appearing on metals. Scientific studies have suggested that free radicals could cause damage to cells and over time lead to diseases such as heart disease and cancer.
Vitamin A is especially essential for having good eyesight. But as an antioxidant, it is not as well established as Vitamins C and E. When obtained from fruits and vegetables or plants, it is in the form of a compound known as beta-carotene which can be converted into vitamin A in our bodies. It is also important for healthy skin.
The most important role of Vitamin B2 (riboflavin) is to help the body to metabolize fats, proteins and carbohydrates. Just like Vitamin A, it is also not well know for its antioxidant properties as such.
Vitamin C (ascobic acid) is a well-known powerful antioxidant. It is essential for the repairing of tissues throughout our bodies. As a water-soluble vitamin, it seems to be more ‘specialized’ in its work as an antioxidant in those watery surroundings within out bodies such as within the cells themselves. According to Prof. Balz Frei of the Linus Pauling Institute, in his question and answer session, Vitamin C is capable of interacting with and regenerating Vitamin E which is a fat-soluble vitamin. He also said that although Vitamin C might not have the antioxidant capacity of the flavonoids, it is more reactive in scavenging the free radicals.
Also, a preliminary study conducted by Prof. Mario Ferruzzi and his team of researchers at Purdue University suggested that Vitamin C might help in the absorbtion of polyphenols catechins. Further research will need be carried out on human subjects.
This is another potent antioxidant. Being a fat-soluble vitamin, it is more ‘specialized’ in protecting the fatty acids in the cell membrane from oxidation. An interesting point in this connection is the possible synergistic interaction between vitamin E and the polyphenol catechins specifically the egcg in preventing the arteries from being clogged.
Vitamin E being a fat soluble vitamin is more suited to the task of preventing the oxidization of the bad cholesterol known as LHL cholesterol which is predominantly fats. When LHL cholesterol is oxidized, it begins to stick to the wall of the arteries and form plaque leading to a condition called atherosclerosis. This in effect narrows the arteries and restricts the supply of blood to all parts of the body which may result in a heart attack or stroke.
This task of guarding the LHL cholesterol from oxidation takes a heavy toll on Vitamin E. Although Vitamin E can be regenerated by Vitamin C, studies conducted by Prof. Catherine Rice-Evans of King’s College London suggests the possibility of the polyphenol cathchins indirectly safeguarding the LHL cholesterol from oxidation and thus preventing the depletion of Vitamin E. Polyphenol catechin being a water-soluble antioxidant which dissolves only in water (but not in fats) does not work in a fats surroundings like inside a LHL molecule. But, operating from a watery surroundings outside of the LHL molecule, it is possible that the polyphenols catechins may intercept or scavenge and quench these free radicals before they can even get to the LHL cholesterols.
The main function of vitamin K is blood clotting and the building of bone mass. Not a well known antioxidant but research indicates that being a fat-soluble vitamin it interacts with Vitamin E in scavenging free radicals in the cell membrane particularly protecting linoleic acid which is an essential omega 6 fatty acid for our good health.
It is quite unlikely that green tea will often be cited as a significant source of vitamins. At any rate, vitamins are commonly found in the wide spectrum of fresh fruits and vegetables and generally for most of us we can have an adequate supply by eating a balanced diet. What makes green tea stand out in its health benefits is its peculiar combination of catechins polyphenols working together with the green tea vitamins. This article serves to inform the types of vitamins that could be found in green tea and their synergistic interaction with the other antioxidant compounds. We are merely scratching the surface here and research continues unabated in unraveling the properties in green tea. It is hoped that this together with the related articles in this category go to show to some extent how complete the camellia sinensis tea plant is as a significant source of antioxidants. The next time when you are brewing your tea, just be mindful that it’s a healthy drink you are preparing.