Coffee and Green Tea As a Large Source of Antioxidant Polyphenols in the Japanese Population

Abstract

Food and beverages rich in polyphenols with antioxidant activity are highlighted as a potential factor for risk reduction of lifestyle related diseases. This study was conducted to elucidate total polyphenol consumption from beverages in Japanese people. Total polyphenol (TP) contents in beverages were measured using a modified Folin-Ciocalteu method removing the interference of reduced sugars by using reverse-phase column chromatography. A beverage consumption survey was conducted in the Tokyo and Osaka areas in 2004. Randomly selected male and female subjects (10-59 years old, n = 8768) recorded the amounts and types of all nonalcoholic beverages consumed in a week. Concentration of TP in coffee, green tea, black tea, Oolong tea, barley tea, fruit juice, tomato/vegetable juice, and cocoa drinks were at 200, 115, 96, 39, 9, 34, 69, and 62 mg/100 mL, respectively. Total consumption of beverages in a Japanese population was 1.11 +/- 0.51 L/day, and TP contents from beverages was 853 +/- 512 mg/day. Coffee and green tea shared 50% and 34% of TP consumption in beverages, respectively, and contribution of each of the other beverages was less than 10%. TP contents in 20 major vegetables and 5 fruits were 0-49 mg and 2-55 mg/100 g, respectively. Antioxidant activities, Cu reducing power, and scavenging activities for DPPH and superoxide, of those samples correlated to the TP contents (p < 0.001). Beverages, especially coffee, contributed to a large share of the consumption of polyphenols, as antioxidants, in the Japanese diet.

Polyphenol Intake from Beverages in Japan over an 18-Year Period (1996&ndash;2013): Trends by Year, Age, Gender and Season

“…The average polyphenol intake from beverages was within the range of 700-800 mg/d. The polyphenol intake observed in the present study was slightly different from that in our previous study using the survey data in 2004, where children less than 10 y old and elderly individuals aged over 60 y were excluded (8). The polyphenol intake in the present study was equivalent to that in our previous study when estimated in the same age range of the participants.…”

“…We calculated the polyphenol intake from beverage consumption data and their polyphenol contents. The polyphenol contents were reported in our previous report (8,9), as measured by a modified Folin-Ciocalteu method (10). The obtained values were expressed as means.…”

“…In our previous report, the total consumption of beverages in Japanese individuals (aged 10-59 y) was 1.1160.51 L/d, and the intake of polyphenols from beverages was estimated to be 8536512 mg/d; this amount was influenced by age rather than by gender (8). However, there is no information on children under 10 or elderly people over 60 y old.…”

In vitro antioxidant and pancreatic α-amylase inhibitory activity of isolated fractions from water extract of Qingzhuan tea

“…Correlation analysis between the levels of total polyphenols and catechins and EC 50 values were undertaken and both were greatly correlated with DPPH assays (r 2 =0.607 and r 2 =0.654, respectively). Previous studies reported similar correlations between these parameters for green tea and other types of tea products (Fukushima et al 2009;Anesini et al 2008;Karori et al 2010). It was inferred that DPPH radicalscavenging activity was likely due to polyphenols and catechins existed in the Qingzhuan tea extracts.…”

Coffee with a high content of chlorogenic acids and low content of hydroxyhydroquinone improves postprandial endothelial dysfunction in patients with borderline and stage 1 hypertension

“…Coffee contains an abundance of polyphenols, which is the major source of dietary antioxidants [13,14]. Drinking coffee is associated with lower risks of metabolic syndrome, diabetes, and coronary heart disease [15][16][17][18][19].…”