This story reports on the results of a large, population-based study in Japan looking at green tea consumption and overall mortality, heart disease mortality and cancer mortality. The study found that those who drank five or more cups of green tea daily had a significantly lower risk of dying of heart disease, but not of dying from cancer.
The story does a good job of describing the latest study as well as other studies that have shown conflicting results. The story also provides needed balance by quoting multiple independent experts.
The major flaw of the story is in the quantification of benefits. The story quantifies the benefits in relative terms only. The story should have provided more context for these numbers. For example, the story does not explain that, in spite of the large number of participants in the study, the actual number of deaths was very small. The rate of heart disease mortality was only between 2 and 3% (depending on gender) among non-tea drinkers. Reducing this rate by 20 to 30% by drinking 5 or more cups of green tea daily is a better way to look at the same numbers.
The story does not mention the costs of the tea, but we can assume that most people are aware of the range of costs of such products at the grocery store.
The story provides quantification of benefits in relative terms only. So when the story says “31% lower risk of dying from cardiovascular disease,” it doesn’t explain “31% of what?” Absolute terms should be given. The story should have provided more context for these numbers. For example, the story does not explain that, in spite of the large number of participants in the study, the actual number of deaths was very small. The death rate among the participants was between 1 and 3% (depending on the subgroup) over the study period.
The story does state that tea is generally harmless and has no calories.
The story provides an adequate description of the Japanese study as well as the results of other studies that have had conflicting results.
The story does not engage in disease mongering.
The story quotes multiple indpendent experts.
The story does not mention alternatives such as diet and exercise. This would have made the story much stronger.
Green tea is clearly available.
Green tea is clearly not new.
Because the story quotes several independent experts, the reader can assume the story did not rely on a press release as the sole source of information