Alcohol consumption is associated with hyperuricemia and gout. Previous studies have indicated a role for green tea catechins in uric acid (UA) metabolism. This study aimed to elucidate the acute effect of green tea catechins in terms of enhancing urinary excretion of UA and xanthine/hypoxanthine (Xa/HX; UA precursors) after alcohol ingestion. In a randomized crossover study, ten healthy Japanese subjects consumed test meals, including a Japanese distilled spirit (Shōchū) with water (SW) or Shōchū with catechin-rich green tea (SC), each containing 20 g of alcohol. The SC contained 617 mg of catechin in total. Serum and urine UA and Xa/HX concentrations were measured. Blood samples were collected after 2.5 h, and urine samples were collected between 0 and 5 h after consuming the test meal. Urine UA and Xa/HX excretions were signi cantly higher in the SC group than in the SW group. UA clearance and fractional UA excretion tended to increase more in the SC group than in the SW group. No signi cant differences in serum UA and Xa/Hx concentrations were observed between two groups. It was concluded that green tea catechins can enhance the excretion of UA and Xa/HX, even though alcohol is ingested.

Fructose is associated with hyperuricemia and gout development. Focusing on fructose and fructose-containing disaccharides, we investigated the effects of three different types of carbohydrates (fructose, sucrose, and isomaltulose) on uric acid metabolism and gene expression profiling in peripheral white blood cells. In a randomized crossover study, ten healthy participants ingested test drinks of fructose, sucrose, and isomaltulose, each containing 25 g of fructose. Plasma glucose, serum and urine uric acid, and xanthine/hypoxanthine concentrations were measured. Microarray analysis in peripheral white blood cells and real-time reverse transcription polymerase chain reaction were examined at 0 and 120 in after the intake of test drinks. Serum uric acid concentrations for group fructose were significantly higher than group sucrose at 30-120 min and were significantly higher than those for group isomaltulose at 30-240 min. Several genes involved in the "nuclear factor-kappa B signaling pathway" were markedly changed in group fructose. No significant differences in the mRNA expression levels of tumor necrosis factor, nuclear factor-kappa B, interleukin-1β, and interleukin-18 were noted. This study indicated that fructose intake (monosaccharide) elevated serum uric acid concentrations compared with disaccharide intake. Differences in the quality of carbohydrates might reduce the rapid increase of postprandial serum uric acid concentrations.

Objective: Alcohol consumption is associated with hyperuricemia and gout. Previous studies have indicated a role for green tea catechins in uric acid (UA) metabolism. This study aimed to elucidate the acute effect of green tea catechins in terms of enhancing urinary excretion of UA and xanthine/hypoxanthine (Xa/HX; UA precursors) after alcohol ingestion.Methods: In a randomized crossover study, ten healthy Japanese subjects consumed test meals, including a Japanese distilled spirit (Shōchū) with water (SW) or Shōchū with catechin-rich green tea (SC), each containing 20 g of alcohol. The SC contained 617 mg of catechin in total. Serum and urine UA and Xa/HX concentrations were measured. Blood samples were collected after 2.5 h, and urine samples were collected between 0 and 5 h after consuming the test meal.Results: Urine UA and Xa/HX excretions were significantly higher in the SC group than in the SW group. UA clearance and fractional UA excretion tended to increase more in the SC group than in the SW group. No significant differences in serum UA and Xa/HX concentrations were observed between two groups.Conclusions: It was concluded that green tea catechins can enhance the excretion of UA and Xa/HX, even though alcohol is ingested.

Alcohol consumption is associated with hyperuricemia and gout. Previous studies have indicated a role for green tea catechins in uric acid (UA) metabolism. This study aimed to elucidate the acute effect of green tea catechins in terms of enhancing urinary excretion of UA and xanthine/hypoxanthine (Xa/HX; UA precursors) after alcohol ingestion. In a randomized crossover study, ten healthy Japanese subjects consumed test meals, including a Japanese distilled spirit (Shōchū) with water (SW) or Shōchū with catechin-rich green tea (SC), each containing 20 g of alcohol. The SC contained 617 mg of catechin in total. Serum and urine UA and Xa/HX concentrations were measured. Blood samples were collected after 2.5 h, and urine samples were collected between 0 and 5 h after consuming the test meal. Urine UA and Xa/HX excretions were significantly higher in the SC group than in the SW group. UA clearance and fractional UA excretion tended to increase more in the SC group than in the SW group. No significant differences in serum UA and Xa/Hx concentrations were observed between two groups. It was concluded that green tea catechins can enhance the excretion of UA and Xa/HX, even though alcohol is ingested.

Background Alcohol consumption is associated with hyperuricemia and gout. Previous studies have indicated a role for green tea catechins in uric acid (UA) metabolism. This study aimed to elucidate the effect of green tea catechins in terms of enhancing urinary excretion of UA and xanthine/hypoxanthine (Xa/HX) after alcohol ingestion.Methods In a randomized crossover study, 10 healthy subjects consumed test meals, including a Japanese distilled spirit (Shōchū) with water (SW) or Shōchū with catechin-rich green tea (SC), each containing 20 g of alcohol. The SC contained 617 mg of total catechin. Serum and urine UA and Xa/HX concentrations were measured. Blood samples were collected after 2.5 h, and urine samples were collected between 0 and 5 h after consuming the test meal.Results Urine UA and Xa/HX excretions were significantly higher in the SC group than in the SW group ( P < 0.05). UA clearance and fractional UA excretion tended to increase more in the SC group than in the SW group. No significant differences in S-UA and S-Xa/Hx concentrations were observed between the SW and SC groups.Conclusions Based on these observations, it was concluded that green tea catechins can enhance the excretion of UA and Xa/HX, even though alcohol is ingested.Trial registration The protocol was approved by the Ethics Committee of the University of Shizuoka and registered with UMIN (University Hospital Medical Information Network in Japan). Trial registration number: UMIN000040076. Registered 7 April 2020 – Retrospectively registered, https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000045687