EFFECTS OF LONG-TERM ORAL ADMINISTRATION OF GREEN TEA CULTIVATED IN DIFFERENT DISTRICTS IN JAPAN ON BODY WEIGHT, BLOOD LIPID AND GLUCOSE LEVELS ON db/db MICE

Previous research using short‐term animal experiments has indicated that oral administration of green tea can suppress elevation of blood sugar. However, few data are available on the antihyperglycemia effect of green tea in long‐term experiments. In this study, effects of long‐term (up to 16 weeks) administration of green tea preparations on body weight, blood sugar and lipid content of db/db and db/+m mice were examined. Preparations were prepared by the same procedure from tea leaves cultivated in different districts in Japan. Significant differences (P < 0.05) were observed in the blood parameters and body weight between control and green tea groups of db/db mice. In the case of normal mice, however, no significant difference was observed. In addition, the response to the administration of green tea depended on the source and composition of tea leaves.