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Tea has been reported for many years to have beneficial health effects. Unfortunately, there have been few studies to substantiate this. Black tea and green tea have different chemical structures and therefore, may have differenct effects on health. Both have had anecdotal reports of benefits.

Recently there has been an observational study that has shown positive health effects of tea ingestion. It was reported in the May issue of the American Journal of Clinical Nutrition. The study was out of Holland. Many longitudinal studies are done in Holland because they have an excellent system for capturing information on populations over time and the population is very stable. Keep in mind what is true in one population, may not hold for other populations or races.

Nevertheless, the researchers studied 4807 people aged 55 who had no history of heart disease. People were followed on average for 5.6 years. During that time, there were 146 incidents in the entire population, of which 30 were fatal. When they analyzed the data, those who drank more than 375 ml. (about 12 ounces) of tea per day were 43% less likely to have a heart attack and 70% less likely to have a fatal heart attack.

How might tea work to lower the risk. Black tea has bioflavinoids in it. Bioflavinoids seem to have a protective effect on the circulation of the heart. The authors write “Our findings suggest a protective effect of  tea and flavinoid intakes against MI (myocardial infarction). The structure of flavinoids shows similarities to that of isoflavones on soy, for which beneficial cardiovascular actions have been reported. More research is needed to assess whether the estrogenic effect of tea is bioogically important.

What is my take on this research? First of all, observational studies have less scientific validity that randomized studies. It is possible that those people who drank tea also has other habits that were beneficial on the heart. This is impossible to control for unless you have a randomized study, which this was not. On the other hand. tea has not been shown to have any harmful effects, so if it may help, that is good. Indeed, drinking tea regulary could be very good for you and there is a biologic model of how it could work. On the other hand, tea drinking is no substitute for other good heart health habits (stopping smoking, regular exercise, controlling cholesterol and blood pressure).

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