New Delhi, 24 January 2008

CUP THAT KEEPS DOCTOR AWAY!

By Dhurjati Mukherjee

It is a healthy and stimulating beverage and might be a greater anti-oxidant than most fruit and vegetables. Drinking just one cup is equivalent to eating one portion of vegetables. It helps to maintain a proper fluid balance essential to the human body and the addition of sugar and milk provides it a certain amount of nutrition, especially when calorie intake in developing countries is lower than the minimum amount required for good health.   

Besides, tea is not merely a cup that cheers, it also cures. While the American Health Foundation and the UK Tea Council feel that a cup of tea keeps the doctor away, scientific research in Japan and China which is centred on green tea, given that the two nations account for 25% consumption, assert that had the Japanese who are prone to peptic ulcer not been drinking tea their condition would have been worse.   

With a growing consciousness of healthy life styles, scientists are disseminating evidence on the health benefits of drinking tea. Some of the encouraging findings linking tea with human health are: (i) Tea flavonoids demonstrate powerful antioxidant activities and protect against cardiovascular diseases; (ii) It provides sufficient levels of fluoride to contribute to improved dental health, particularly in regions where fluoride is not added to water supply; (iii) It lowers blood cholesterol;

Tea pigments reduce the blood coagulability and increase fibrinolysis, (v) Tea, without milk and sugar, hardly contains any calories and may be used where a low calorie intake is desired, the message being that a cup of hot tea with meals will improve intestinal mobility and gastric emptying; (vi) It is a rich source of potassium, specially in diets which are low in this mineral; (vii) Black tea prevents against ulceration.

Apart from these, tea has also been identified as a chemo-preventive agent against cancer. Studies show that certain constituents in tea protect against different types of cancer (skin, lung, duodenum, fore stomach, liver, colon etc). In fact, much of the cancer preventive effects of green tea are mediated by ECGC, the major polyphenolic constituent of green tea. And its consumption shows 90 per cent efficacy in preventing prostrate cancer.

Besides, tea has a low caffeine content which varies from 2.5 and 5 per cent on a dry weight basis. Out of this, about 80 per cent is extracted when tea is brewed in hot water. A daily consumption of 5 cups of tea means a caffeine intake of 0.3 gm, which is well below the tolerable limit (of 0.65 gms) prescribed and is not harmful to health. Caffeine and its metabolites do not accumulate in the body but are demethylated, oxidized and excreted. 

In fact, caffeine stimulates the brain and the nervous system. It is a natural sedative and allows the body to carry on without slowing down. The stimulating effect of caffeine results in discriminatory ability, increased accuracy of sensations and sensitivity of taste and smell. High caffeine intake could, however, increase gastric activity but there is no evidence that this can happen with the intake of tea. Though over the past three decades, cancer of bowels, breasts, ovaries, bladder etc. has been linked to caffeine, there is no convincing evidence relating tea to any type of cancer.

In India, tea is not considered a health drink but a very popular beverage. The moment there is addition of milk to tea, the actual effectiveness and originality of the tea is lost as also its medicinal effect. But though research on tea, specially analyzing the effectiveness of tea as a health drink has just been undertaken in the country, scientists and planters are eager to popularize tea as a health drink. But for this scientific studies have still to be taken up.

However, research has shown that black tea acts as a double-edged sword in the treatment of cancer by directly killing tumor cells via ‘apoptosis’ or ‘programmed cell death’ and protecting and potentiating the intrinsic defense machineries, including the immune system of the tumor-bearing host. Experiments conducted on mice and human cancer cell lines e.g. breast cancer, prostrate cancer, lung cancer etc. in which black tea and its polyphenols have shown promising results.

Black and green tea consumption was found to be effective in preventing diabetes. Black tea extracts also produced a concentration-dependent facilitation of muscle responses to nerve stimulation and antagonized different agents causing muscular paralysis. These experiments have indicated a stimulatory effect on the nerve-muscle transmission process by helping muscle contraction in general. It has further been established that tea had anti-bacterial properties and is effective against diahorrea and cholera.

Needless to say, tea, science and human health are intrinsically linked and the consumer has to be made aware of this through sustained promotional campaigns. At a time when chronic diseases such as heart, hypertension and many types of cancer are increasing being linked to hectic lifestyles, the insufficient consumption of protective foods (fruits and vegetables) and beverages such as black or green tea, containing essential antioxidants, could be highly beneficial.

In sum, it is difficult to predict whether tea would become a potent weapon against chronic diseases in the near future, but it can be affirmed that tea research has been neglected. More funds have to be made available both by the Government and the industry, not just for exploring ways and means for increasing productivity through superior clones but also for experimenting on tea’s medicinal values and its effect on human health. ---- INFA

(Copyright India News & Feature Alliance)