Source density analysis of EEG recordings from 12 healthy human volunteers was used in a randomized, placebo controlled cross over study to investigate the change in physiological parameters after ingestion of a soft drink containing green tea extract enriched with L-theanine and theogallin. EEG was recorded 1, 2, 3 and 4 h after ingestion during different recording conditions. Visually evoked P300 potentials were recorded every hour in addition to the EEG recordings.Analysis of the data revealed a general attenuation of electrical delta power under the condition of eyes open during the first hour (statistically significant at p < 0.01). During a reading test increases of delta and theta power were observed at frontal electrode sites starting with the second hour after administration, significant at the third and fourth hour ( p < 0.04) in comparison to placebo. These changes indicate a higher level of mental performance. Increases of beta1 power starting with the second hour indicated a higher degree of relaxation. However, no statistical significance was reached.Analysis of visually evoked P300 waves revealed a decrease in latency at the last hour ( statistical significance p, 0.04) as well as increases of amplitudes at the electrode position C-z (from the first to the third hour, statistically not significant). This type of result in general suggests an improvement of attention. Thus, decaffeinated extract of green tea still has a stimulating effect despite the lack of caffeine presumably due to its high content in L-theanine and theogallin as found in preclinical experiments.

Green tea is known to have stimulating properties which are believed to derive from caffeine. The present project was initiated to characterize a theanine and theogallin enriched decaffeinated extract of green tea in a beverage using electrophysiological parameters in vitro, in vivo (rat) and in humans (randomized trial in comparison to placebo). Oral administration of 2.5 grams of this extract led to statistically significant changes of physiological brain activity in volunteers. Already one hour after intake of the drink containing the extract basic delta activity of the quantitatively processed electroencephalogram in frontal areas was attenuated. This decrease allows higher increases of delta power during mental work as known from earlier work. This result was indeed corroborated by higher production of delta and theta waves during reading an essay indicating better cognitive performance. Analysis of a visually evoked P300 wave revealed shorter latencies in the presence of the extract in comparison to placebo again pointing to improvement of cognitive capabilities. At the same time beta1 waves from the EEG increased compatible with a higher state of relaxation.

Functional food products should provide scientifically proven beneficial effects in healthy subjects.The highly sensitive method of EEG recording from healthy human volunteers was used in a randomized, placebo controlled crossover study to investigate the effects of a change in physiological parameters after ingestion of a total of 750 ml of a softdrink containing 0.232 g of ginseng and 2 g of ginkgo extract, both produced by water extraction. Application of a random, placebo controlled crossover design was done with 10 healthy male volunteers. EEG recordings were performed 1, 2, 3 and 4 h under the conditions of 10 min eyes open, 5 min eyes closed and 5 min reading short stories. Auditory P300 potentials were recorded every hour in addition to the EEG recordings.Source density analysis of the data revealed an attenuation of circadian induced electrical delta power decreases under the condition of eyes open and closed recording from centro-parieto-occipital electrode positions. During a reading test even absolute increases of delta power were observed at these electrode sites. These changes were statistically significant at p < 2 % for the second hour (eyes open and reading) and are interpreted to indicate a higher degree of emotional well-being.Decreases in latency (from 333.9 to 321.3 ms) as well as increases of amplitude (from 2.07 to 3.95 mu V) of the auditory P300 potential at the electrode position Pz point to a possible improvement of attention, however, the difference did not reach statistical significance.

Pharmacokinetic parameters of several dietary anthocyanins following consumption of Hibiscus sabdariffa L. extract were determined in 6 healthy volunteers. Subjects were given a single oral dose of 150 mL of Hibiscus sabdariffa L. extract yielding 62.6 mg of cyanidin‐3‐sambubioside, 81.6 mg of delphindin‐3‐sambubioside, and 147.4 mg of total anthocyanins (calculated as cyanidin equivalents). Within 7 hours, the urinary excretion of cyanidin‐3‐sambubioside, delphinidin‐3‐sambubioside, and total anthocyanins (ie, the sum of all quantifiable anthocyanidin glycosides) was 0.016%, 0.021%, and 0.018% of the administered doses, respectively. Maximum excretion rates were determined at 1.5 to 2.0 hours after intake. The dose‐normalized plasma area under the curve estimates were 0.076, 0.032, and 0.050 ng•h/mL/mg for cyanidin‐3‐sambubioside, delphinidin‐3‐sambubioside, and total anthocyanins, respectively. The dose‐normalized C max estimates were 0.036, 0.015, and 0.023 ng/mL/mg in the same sequence. They were reached each at 1.5 hours (median) after intake. The geometric means of t 1/2 were 2.18, 3.34, and 2.63 hours for cyanidin‐3‐sambubioside, delphinidin‐3‐sambubioside, and total anthocyanins, respectively. The urinary excretion of intact anthocyanins was fast and appeared to be monoexponential. To evaluate the contribution of anthocyanins to the health‐protecting effects of Hibiscus sabdariffa L. extract, it will be necessary to perform further studies on both the intact glycosides and their in vivo metabolites or conjugates in human plasma and urine.