BackgroundResults of epidemiological studies have suggested that consumption of green tea could lower the risk of type 2 diabetes. Intervention studies show that green tea may decrease blood glucose levels, and also increase satiety. This study was conducted to examine the postprandial effects of green tea on glucose levels, glycemic index, insulin levels and satiety in healthy individuals after the consumption of a meal including green tea.MethodsThe study was conducted on 14 healthy volunteers, with a crossover design. Participants were randomized to either 300 ml of green tea or water. This was consumed together with a breakfast consisting of white bread and sliced turkey. Blood samples were drawn at 0, 15, 30, 45, 60, 90, and 120 minutes. Participants completed several different satiety score scales at the same times.ResultsPlasma glucose levels were higher 120 min after ingestion of the meal with green tea than after the ingestion of the meal with water. No significant differences were found in serum insulin levels, or the area under the curve for glucose or insulin. Subjects reported significantly higher satiety, having a less strong desire to eat their favorite food and finding it less pleasant to eat another mouthful of the same food after drinking green tea compared to water.ConclusionsGreen tea showed no glucose or insulin-lowering effect. However, increased satiety and fullness were reported by the participants after the consumption of green tea.Trial registration numberNCT01086189

Background: Tinnitus sufferers commonly report concentration difficulties. Despite several previous studies investigating this, the underlying cause and the role of hearing status remains unclear. Purpose: To investigate whether there are any differences between normal hearing individuals with and without tinnitus in terms of working memory capacity, and whether working memory capacity correlates with high-frequency hearing thresholds. Research Design: Participants had their hearing thresholds measured (0.125?16 kHz) and performed a visual n-back test. All participants completed the Hospital Anxiety and Depression Scale, in addition tinnitus participants filled out the Tinnitus Questionnaire. Study Sample: Sixty-two individuals participated, 31 had tinnitus (tinnitus group) and 31 did not have tinnitus (control group). Groups were age- and sex matched, and all participants had normal hearing thresholds (20 dB HL or better at 0.125?8 kHz). Data Analysis: Friedman test of differences among repeated measures was conducted on the collected data of n-back performance, and Mann?Whitney U-test was used to compare groups. Age-corrected correlations were calculated for high-frequency hearing and each n-back condition. Results: We found no significant differences between the groups in terms of n-back task performances, except for the 2-back condition where the tinnitus group performed significantly better than the controls (p = 0.007). Furthermore, we found high-frequency hearing thresholds of the best ear (10?16 kHz) to correlate with performances at more demanding n-back conditions (p = 0.029 for 1-back and p = 0.015 for 2-back). Conclusion: This suggests that presence of tinnitus might not imply poorer working memory capacity and that deteriorated high-frequency hearing thresholds.