Therefore the report last week in the Journal of the American Medical Association where a team of Japanese researchers had claimed that they were able to link green-tea consumption with decreased mortality from all causes--including cardiovascular disease, was met with interest.
According to the report the researchers tracked 40,530 healthy adults of ages 40 to 79 in a region of northeastern Japan where most people were green tea drinkers, following them for up to 11 years. The research revealed that those who drank five or more cups of green tea a day had significantly lower mortality rates than those who drank less than one cup a day. In addition it was found that there were also fewer deaths from cardiovascular disease.
However such association was not reported with deaths from cancer. Besides this consumption of oolong or black tea also did not show any decrease in mortality. Such teas besides being more oxidized in processing, not only darkens the color of the leaves but also changes their flavor and reduces their polyphenol content.
The kind of green tea that the Japanese have access to is of better-quality than that of most North Americans'.
The benefits or ills of Coffee are still not very clear having received both laurels and black marks in the medical literature. Although it too contains antioxidants they role has not been as well studied as that of tea polyphenols. Evidence for the health benefits of coffee is growing, however.
For instance in the August issue of the European Journal of Clinical Nutrition, a group of investigators from Finland, Italy and the Netherlands report that coffee seems to protect against age-related cognitive decline. The researchers studied 676 healthy men born from 1900 to 1920 following them for 10 years, using standardized measures of cognitive function. They concluded that men who consumed coffee had significantly less cognitive impairment than those who didn't. Maximum protection was offered by three cups of coffee a day.
Such population studies help us to form hypotheses about relationships between dietary habits and long-term health.