Indian Tea Association:Antioxidants

Antioxidants- The key to a healthy life

Antioxidants, is the simple answer to a regular life of health and energy. It is one of the key requirements for human nutrition and are present in very common food and beverage items that we consume daily. Biochemists have observed that most blocking agents for Cancer are scavengers of electrophiles and free radicals. These agents exhibit Antioxidant activity through their ability to scavenge oxygen radicals inclusive of singlet oxygen, peroxy radicals, super oxide anion and hydroxyl radicals (Harman 1982).

The Power of Antioxidants

Antioxidant defenses normally protect against DNA damage caused by reactive oxygen species from endogenous and exogenous sources. Reduced levels of Antioxidants are, therefore, associated with increased Cancer, Atherosclerosis and several other diseases.

Antioxidant defenses normally protect against DNA damage caused by reactive oxygen species from endogenous and exogenous sources.
Reduced levels of Antioxidants are, therefore, associated with increased Cancer, Atherosclerosis and several other diseases.
Supplementing the human diet with the vitamin Antioxidants helps to prevent a number of diseases.
Combinations of synergistic Antioxidants acting by complementary mechanism are much more effective than individual Antioxidants.
Flavonols have, in recent years, emerged as important chain-breaking Antioxidants.
Tea, a significant source of Flavonoid Antioxidants, has more Antioxidant properties than 22 vegetables containing Antioxidants.
Black Tea contains Theaflavins which is most powerful in abrogating RNS production.

The power of Antioxidants is correlated to Life Span Energy Potentials (LSPs). A similar relationship has also been found for uric acid, a powerful water-soluble Antioxidant in primates, while, Carotene also appears to improve longevity though the effect is non-linear. Concentrations of Vitamin E (tocopherol) in the plasma also show a good correlation. There is also adequate evidence that supplementing the human diet with the vitamin Antioxidants helps to prevent a variety of diseases, such as Cancer and Coronary Heart diseases (Duthie, 1993; Scott 1993).

Hence, apart from the Antioxidants present in the human body for the inherent protection system, Antioxidants also need to be consumed through various nutritional habits to give that extra protection especially to prevent aging and diseases caused due to aging.

Tea and other plant foods are dietary sources of nutrients as Carotenoids, Tocopherols, Ascorbic acid, and non nutrient Phytochemicals generally classified as Flavonoids. Epidemiological evidence suggest that increased intake of plant puts reduced the risk of Cancer and Coronary Heart disease, the main causes of human mortality. Tea, a significant source of Flavonoid Antioxidants - Physiologically, has active compounds in vitro and in vivo with a suggested role in prevention of Cancer and Coronary Heart diseases. Tea however has more Antioxidant properties than the 22 vegetables (listed at the end of this section) containing Antioxidants, which were tested accordingly.

In recent years, it has also been observed that combinations of synergistic Antioxidants acting by complementary mechanism are much more effective than individual Antioxidants. Vitamin E alone is relatively ineffective without Ascorbic acid. Supplements should therefore normally be administered as balanced combinations of chain-breaking and preventive Antioxidants (Scott, 1993; Gey 1994). Flavonols have, in recent years, emerged as important chain-breaking Antioxidants. Research thrust has thus shifted to Flavonols in recent years, which has emerged as important chain-breaking Antioxidants (Harborne 1989) and epidemiologic observations and laboratory studies have indicated that Polyphenolic compounds are powerful Antioxidants which may reduce the risk of a variety of illnesses, including Cancer and Coronary Heart disease.

Of great relevance for human health is research, that the beverage, Tea, provides an excellent means of lowering the risk of heart disease, and many Cancers. In a recent work (Bhaduri 2001) the constituents of Black Tea were separated out and each component was added stepwise to assess the efficacy of individual components. Such addition showed that though all the constituents of Black Tea contributed to the overall health effect of Black Tea, Theaflavin was the most powerful in abrogating RNS production. It also showed that Theaflavins are the most important constituent in down regulating expression of inducible nitric oxide synthase. Theaflavins in Black Tea result from bio-transformation of catechins during processing and clearly, Black Tea is an excellent chemo-preventer against reactive oxygen and nitrogen specii.

Total Antioxidant Capacity of Tea and Common Vegetables

Item	Antioxidant Capacity*	Item	Antioxidant Capacity*
Tea	927	Garlic	46 + 9
Green Tea	814 + 30	Onion	40 + 2
Kale	179 + 32	Iceberg Lettuce	39 + 12
Spinach	129 + 6	Cabbage	32 + 2
Alfalfa Sprout	117 + 12	Carrot	26 + 8
Beets	81 + 25	Corn	22 + 4
Red Bell Pepper	74 + 9	Yellow Squash	17 + 3
Brussels Sprout	70 + 10	Potato	15 + 5
Broccoli Flowers	59 + 5	Cucumber	15 + 2
Eggplant	50 + 22	Sweet potato	14 + 2
Leaf Lettuce	49 + 7	Celery	13 + 2
Cauliflower	46 + 11	-	-

*The Antioxidant Capacity is measured by oxygen radical absorbance method using peroxyl radical(AAPM). Trolox is a common Antioxidant and 1 m mol of Trolox = 1 gm of dry matter.

Ref: Cao G, Sofic E, Prior RL (1996): Antioxidant Capacity of Tea & Common Vegetables