By Lori Bricker, MS, RD
Recently, I posted a summary of a research paper based on data from the Ohsaki study, which included over 42,000 residents of Ohsaki City, Japan, aged 40 and over, initiated in 1994. Multiple papers have recently been published as the huge amount of data from this study has been analyzed. The best news for us is that study participants provided information on their green tea intake, so correlations between tea intake and a number of different medical conditions are becoming available. Participants answered a questionnaire in which they reported their usual intake of green tea as never, occasionally, or 1-2, 3-4, or > 5 cups per day (1 cup was considered to be 100mL). The participants’ medical conditions were followed up to 12 years after the onset of the study. Without going into detail, here are some of the basic findings so far, each one the conclusion of a separate paper based on the Ohsaki data:
- “Green tea consumption was associated with a lower risk of death from pneumonia in Japanese women.” No such association was found for men. Am J Clin Nutr, Vol. 90, No. 3. (1 September 2009), pp. 672-679.
- “Green tea consumption is associated with reduced mortality due to all causes and due to cardiovascular disease but not with reduced mortality due to cancer.” The authors note that this association with reduced mortality for all causes and cardiovascular disease was stronger in women than in men. JAMA, Vol. 296, No. 10. (13 September 2006), pp. 1255-1265.
- “Green tea consumption is associated with a reduced risk of liver cancer incidence.” Cancer causes & control : CCC (19 September 2009).
- “Green tea consumption was associated with a lower risk of hematologic malignancies” [cancers of the blood, bone marrow, and lymph, such as leukemia]. Am. J. Epidemiol., Vol. 170, No. 6. (15 September 2009), pp. 730-738.
- “This cohort study has found no evidence that green tea consumption is associated with lung cancer.” British Journal of Cancer, Vol. 99, No. 7. (7 October 2008), pp. 1179-1184.
It’s great to see tea research done with such large populations over longer periods of time. As more information becomes available, I will post it here.
For links to all these study abstracts, please visit my saved page on CiteULike:
This is great information on green tea. More people need to read this.
I also like to see these studies of large masses of people. I’m partial to the epidemiological approach. It shows how tea combined with a sensible diet doesn’t lead to the major Western diseases like cardiovascular and cancer.