Three new studies by Japanese scientists add even more evidence to what already is an astounding mountain of data showing green tea protects and heals the human body. All of the research is based on findings from the huge Ohsaki National Health Insurance Cohort Study in Japan which involved 41,761 Japanese adults between 40 and 79 years of age. None of the research subjects had a history of cancer when the study started and their diets, along with other lifestyle factors and any health problems they developed, were followed for about ten years.
In a study published in the September issue of the American Journal of Epidemiology, Dr. Toru Naganuma of Tohoku University School of Medicine in Senda and colleagues reported that drinking at least five daily cups of green tea was found to slash the risk of blood cancers by 42% and lymph system cancers by 48%. What’s more, these enormous reductions in cancer were consistent in both men and women and in people with various body mass sizes.
While Dr. Naganuma was looking at blood and lymph cancer rates, another research team in the Division of Epidemiology in Tohoku University’s Department of Public Health and Forensic Medicine was also searching the Ohsaki National Health Insurance Cohort Study and they discovered yet another link between green tea and cancer prevention. Their study, published in the September issue of the journal Cancer Causes and Control found that green tea consumption was inversely associated with the incidence of liver cancer. The study documented that the more green tea consumed, the more the risk plummeted — five cups or more offered the most protection from liver malignancies.
Yet another study of the Ohsaki data by scientists at the Tohoku University Graduate School of Medicine, published in the September edition of the American Journal of Clinical Nutrition, found a strong link between drinking green tea and protection against pneumonia in women. The researchers noted in their paper that experimental and animal studies have previously shown that catechins, antioxidant phytochemicals found abundantly in green tea, are active against infectious agents — so that could be a possible explanation for green tea’s apparent pneumonia-fighting ability.
They excluded any research participants who were missing information on their green tea consumption or who had reported a history of cancer, heart attack or stroke. In all, the scientists followed the research subjects’ health for over 12 years. The results showed, at least for women, a dramatic reduction in the risk of pneumonia for green tea drinkers. Once again, drinking five or more cups a day appeared to offer the most benefit.