Through this 2 years project, I have made clear the followings :
(1) I recorded the electroencephalogram (EEG) and electrocardiogram (ECG) before and after drinking water or beverages such as carbonated drink and vegetable juice, in order to reveal the human physiological responses to drinking. As a result, drinking cold water or vegetable juice increased the rate of beta -wave and beta / alpha ratio significantly, but they had no significant effect on heart rate and heart rate variability (HRV). On the other hand, drinking carbonated drink afforded different physiological responses than drinking water and vegetable juice. Drinking carbonated drink increased the heart rate and the rate of LF/(LF + HF) significantly. In addition, on EEG obtained at Pz position, drinking carbonated drink increased the rate of beta-wave, while it decreased the rate of alpha-wave.
(2) I have applied the gas chromatographic analysis of hydrogen in expifed air for determination of transit time of diet in intes
tinal tract. Using this technique, I have found two patterns (naming A and B type) of breath H_2 concentration in young university girl students who spend everyday life freely. In typical example for A type, the increase in H_2 concentration occurred 3 4 hours after breakfast. In contrast, it occurred 7 * 8 hours after breakfast in B type. I could not find the significant correlation between these types and dietary and daily habits except for the preference to taking fried foods.
(3)1 have compared the changes in breath H_2 concentration at 10-min intervals with doses of 100 ml of dairy milk under relaxed (without task) and stressed (with task) conditions. Comparison of these changes showed that increases in H2 concentration over baseline level occurred about 2 hours faster under stressed condition than under relaxed condition. However, I could not find significant difference in physiological states, such as in EEG and HRV under these two conditions.
These results obtained in this project indicate that how to take diet may have certain effect on it's transit time in intestinal tract and activity of autonomous nervous system. Less