Introduction: Flavonoids have a variety of functions, such as antioxidant activity, and are expected to have a disease prevention effect. In order to verify the disease risk reduction effect of flavonoids, we carried out a crossover trial in seven adult men of normal or light overweight who ingested flavonoid-rich meals, with a diverse combination of basic foodstuffs, and low-flavonoid meals and compared blood disease-related inflammatory markers.Methods: On the first two days of the study, seven male volunteers were provided with low-flavonoid meals (flavonoid content below the detection limit of HPLC: less than 0.24 mg/meal) three times a day as a washout. For the next seven days, they were fed flavonoid-rich meals (46.9 ± 8.1 mg/meal) or low-flavonoid meals. Blood samples were collected from all the volunteers before breakfast on the third day, after the washout and before breakfast on the tenth day. The test was consisted of one cycle from the first day to the tenth day, and the participants carried out two cycles. Flavonoid concentrations in plasma and gene expression of inflammatory cytokine (interleukin 1 beta, interleukin 6, interleukin 18, and tumor necrosis factor-α) in whole blood cells were compared before and after the intervention. Gene expression in whole blood cells was measured using real time RT-PCR.Results: We found a significant increase in plasma flavonoid concentration (quercetin, kaempferol, daidzein, and genistein) upon intervention with flavonoid-rich meals (p < 0.05). In addition, the inflammatory cytokine gene expression was reduced in the subjects with a body mass index of more than, but not less than, 25 kg/m2 compared with that observed after the intake of low-flavonoid meals.Conclusion: These results suggest that flavonoid-rich meals have an anti-inflammatory effect in obese persons who are likely to have chronic inflammation.Keywords: Flavonoids, inflammatory cytokines, flavonoid-rich meal, human study
Regulation of lipid metabolism-related gene expression in whole blood cells of normo- and dyslipidemic men after fish oil supplementation