Green tea and stomach cancer--a short review of prospective studies.
BACKGROUND
In Japan, green tea has been drunk for a long time. Because it can be drunk casually, many people love drinking it. If such green tea has an effect to prevent stomach cancer, it will be a very convenient way to prevent the disease.


METHODS
To examine the association between green tea consumption and the risk of stomach cancer, past epidemiologic studies including JACC Study were reviewed.


RESULTS
Among eight case-control studies, five showed risk reduction with a statistically significant difference, and two studies showed risk reduction without a statistically significant difference. The remaining study showed the opposite result. Among six prospective studies regarding stomach cancer, no study showed risk reduction with a statistically significant difference. Four of the six studies showed no relation. In terms of study design, prospective studies, which are considered to be more reliable than case-controlled studies, tend to show no risk reduction. The results of case-control studies and prospective studies present considerably different impressions.


CONCLUSIONS
Prospective studies showed no inverse association between the consumption of green tea and the risk of stomach cancer.
Hoshiyama
Yoshiharu
Y
Department of Public Health, Showa University School of Medicine, Saitama, Japan. hosiyama@human.ac.jp
Kawaguchi
Takeshi
T
Miura
Yoshihiko
Y
Mizoue
Tetsuya
T
Tokui
Noritaka
N
Yatsuya
Hiroshi
H
Sakata
Kiyomi
K
Kondo
Takaaki
T
Kikuchi
Shogo
S
Toyoshima
Hideaki
H
Hayakawa
Norihiko
N
Tamakoshi
Akiko
A
Yoshimura
Takesumi
T
D001628:Beverages; D016022:Case-Control Studies; D006801:Humans; D007564:Japan / Q000453:epidemiology; D009752:Nutritional Status; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000453:epidemiology* / Q000517:prevention & control; D013662:Tea
D013662:Tea