This article described a recent study about green tea’s possible impact on cancer and cardiovascular disease. While it raised questions about tea quality and how that might affect the results obtained, no data were given to support the conclusion about which teas would provide the desired benefit. There was nothing in the piece about other things that could account for the findings (eg, healthy habits, genetics), or whether there were other lines of evidence to support this association. There was also no quantification of benefit nor any comparison with other ways to reduce cardiovascular disease risk. A discussion of patterns of eating and drinking in different cultures and the effect of these patterns on disease incidence in populations would have been useful to help the reader put the study results in context.
Although this article did a good job towards the end of explaining the nature of the study from which the information was derived and the limitations of the conclusions that should be drawn, the tone of the article was that green tea was of benefit and that there are finally data to support this contention.
There are no costs mentioned with the type of tea recommended in the article (gyokuro or matcha) though the article suggests vendors of these types of tea. If the story can suggest sellers, it can cover costs, which can vary widely with these products.
The benefits of drinking 5 or more cups of green tea a day was presented as a decreased chance of dying in the 11 year period of the study. However, there was no information about the amount that risk decreased. Although increased green tea consumption was seen to be associated with decreased risk of death from heart disease, the percentage of individuals dying of heart disease was less than half the number in Americans of comparable age. It is difficult to know the meaning of this difference.
There is no evidence presented about the how the type of green tea may influence the outcome of cardiovascular mortality, only that the larger amount of green tea consumed was associated with decreased cardiovascular mortality.
A claim is made in the article that by enjoying tea of the best quality, you are probably doing more good than harm. The article did not mention any potential harms associated with consumption of green tea, even if that would be to say that there are no known risks associated with green tea consumption.
Although the article did mention that the common green teas found in the U.S. may differ in ways that could affect their potential health benefits, no evidence was given that components in the green tea consumed in Japan were associated with the effects observed.
At the end of the article, there is an informative paragraph explaining the type of study from which the data were derived (prospective population study) and that the suppositions still remain to be tested in controlled conditions. It is important for readers to understand that as the study cited was a cohort study, the issue of potential confounders such as diet or other health relevant behaviors might have had a role in the benefits observed. Further, there may also be genetic differences between populations that could affect whether green tea consumption affects health outcomes. The tone of the article was that green tea was of benefit and that there is finally data to support this contention.
Cancer and cardiovascular disease (two major causes of death in the U.S.) are not hyped.
There are no quotes from any investigators in the field. Even if Dr. Weil’s expertise is taken into account as author of the piece, that is still only a single-source perspective.
The article did not mention other ways to decrease cardiovascular mortality risk.
The article discusses differences in the green tea typically available in Japan and in the United States and offers suggestion sabout where Japanese green tea can be obtained. But the suggestion that the results of the study derive only from Japanese green tea and not green tea available in the US is not justified by the study cited.
This article is not about a novel treatment but was stimulated by the results of one recent study.
This article does not appear to rely on a press release.