(Oct 27) SCIENTISTS have long suspected that certain traditional Asian herbs such as lingzhi and green tea contain components that can effectively fight a range of cancers.

Now, a research team helmed by Dr Josh Zhu, senior director of Pharmacology and Clinical Affairs at the Pharmanex Clinical and Pharmacology centres in Beijing, has found conclusive evidence that a combination of green tea and reishi (another term for lingzhi) extracts inhibits cancer growth and may even postpone certain death.

Explaining his team's findings, Dr Zhu says: 'We started the research in 2004 taking extracts from green tea and reishi (above). We realised that both these herbs have beneficial selective functions. Together, they help to kill off cancer cells and arrest tumour growth.'

The team had inoculated laboratory mice with cancer cells before treating them with green tea and reishi extracts. According to Dr Zhu, results showed that the treated mice had 'prolonged lives' compared to their untreated counterparts.

The fact that green tea is beneficial isn't new; neither is the claim that reishi aids the immune system, but this is the first time supplements of the two had been tested in a rigid, clinical setting and found effective, explains Dr Zhu, who was formerly medical director at Beijing Friendship Hospital.

Traditionally, green tea is widely consumed in East Asia. Each year, about 2.5 million tonnes of tea are manufactured from the dried leaves and leaf buds of the shrub Camellia sinensis. Green tea, which is not fermented, is made by steaming or pan-frying tea leaves before drying them. It accounts for almost 20 per cent of world tea production and has been used medicinally as a stimulant and digestive remedy for about 5,000 years. Because of the curing process, the properties of the green tea are very similar to that of the fresh leaf, giving it higher medicinal ratings than black tea.

Previous studies in animals and test tubes have suggested that the polyphenols in green tea can inhibit the growth of breast cancer cells. In one study, for example, researchers found that women who consumed the most green tea experienced the least spread of cancer, particularly premenopausal women in the early stages of breast cancer. They also found that women with early stages of the disease who drank at least five cups of tea every day before being diagnosed with cancer were less likely to suffer recurrences of the disease after completion of treatment.

The addition of reishi into the remedial mix helps to strengthen the immune system even further, claims Dr Zhu, who graduated from Capital University of Medical Sciences, Beijing, and from Stanford University.

Hailed as the 'mushroom of immortality', reishi is a good source of triterpenes and biologically active polysaccharides with presumed medicinal properties.

Citing the case of his own father-in-law, Dr Zhu explains: 'My father-in-law was diagnosed with leukaemia at age 85. Because of his age, his doctor recommended only a half-dose of chemotherapy, with the intention of improving the quality of end-life. We added reishi and green tea to his medicine routine and miraculously, he reached clinical remission and lived on for another two and a half years. Finally, when he died, it wasn't of cancer, but of a heart attack.'

Currently, there are numerous products in the market selling green tea as well as reishi extracts. Dr Zhu cautions, however, that there are different 'grades' of green tea and reishi, so not all supplements are created equal.

Asked if taking supplements is the same as eating the real thing, Dr Zhu claims the former may even be superior. 'Natural green tea, for example, contains caffeine, which works on the nervous and cardiovascular systems. Too much caffeine may not be good for the heart,' he says. Unlike tea leaves, green tea supplements do not contain caffeine.

Moreover, reishi mushrooms do not come cheap, and not many people know how to prepare it, so supplements are a much more convenient alternative.

'It is easier to pop a pill than to eat or drink the actual herb,' says Dr Zhu, who represents a new breed of doctors seeking to turn traditional Chinese medicine into a science, by applying stringent standards in the selection and testing of products.