Dietary Intakes of Flavonols, Flavones and Isoflavones by Japanese Women and the Inverse Correlation between Quercetin Intake and Plasma LDL Cholesterol Concentration

Abstract

The intake of flavonols, flavones and isoflavones by Japanese women was calculated from our food-phytochemical composition table. The relationship between intake of these phytochemicals and various anthropometric and blood chemistry data was analyzed in a cross-sectional study. The subjects were 115 women volunteers, aged 29-78 y, living in the northern part of Japan. Each subject completed a 3-d dietary record and received a health check up, including urine and blood sampling for biochemical analysis. Total mean intakes of flavonoids (sum of flavonols and flavones) and isoflavones were 16.7 and 47.2 mg/d, respectively. The major source of flavonoids was onions (45.9%) and that of isoflavones was tofu (37.0%). Total intake of isoflavones exceeded that of other dietary antioxidants, such as flavonoids, carotenoids (3.5 mg/d) and vitamin E (8.2 mg/d), and was approximately one half of the vitamin C intake (109 mg/d). The total intake of flavonoids was inversely correlated with the plasma total cholesterol concentration (TC) (r = -0.236, P: < 0.05) and plasma LDL cholesterol concentration (LDL-C) (r = -0.220, P: < 0.05), after the adjustment for age, body mass index and total energy intake. As a single component, quercetin was inversely correlated with both TC (r = -0.261, P: < 0.01) and LDL-C (r = -0. 263, P: < 0.01). Among Japanese, flavonoid and isoflavone intake is the main component among nonnutrient phytochemicals with antioxidant potential in the diet. These results suggest that a high consumption of both flavonoids and isoflavones by Japanese women may contribute to their low incidence of coronary heart disease compared with women in other countries.

Modulation of multiple pathways involved in the maintenance of neuronal function during aging by fisetin

“…Among the fruits and vegetables where fisetin can be detected, the highest levels are found in strawberries [2]. Interestingly, supplementation of the diet of 19-month-old rats with a strawberry extract for 8 weeks resulted in enhanced performance in the MWM relative to rats fed a control diet [39].…”

“…The highest levels (160 lg/g) are found in strawberries [2] with five to tenfold lower levels in apples and persimmons. Small amounts are also found in kiwi fruit, peaches, grapes, tomatoes, onions and cucumbers [33].…”

The role of herbs and spices in cancer prevention

“…While not everyone considers onions to be an herb or a spice, onions do provide flavoring and based on available data, they are one of greatest contributors of dietary flavonoids in the U.S., Japanese, Dutch, and Danish populations (25)(26)(27)(28). Of the studies reviewed, only the study of flavonoid intake conducted in Japan (27) identified another herb or spice (parsley) as a significant contributor of flavonoids.…”

“…Of the studies reviewed, only the study of flavonoid intake conducted in Japan (27) identified another herb or spice (parsley) as a significant contributor of flavonoids. Arai et al (27) reviewed 3-day food records and found that onions contributed 45.9% of total daily flavonoid intake, and 83.6% of quercetin intake; whereas parsley provided 2.4% of total daily flavonoid intake, primarily as myricetin. How this contribution relates to an overall phenotypic response remains to be established.…”

Isolation, Characterization, Crystal Structure Elucidation of Two Flavanones and Simultaneous RP-HPLC Determination of Five Major Compounds from Syzygium campanulatum Korth

“…It is reported that the genus Syzygium is rich in secondary metabolites such as terpenoids [2,3], phenylpropanoids [4], chalcones [5], flavonoids [6], lignans [7], alkyl phloroglucinols [8], hydrolysable tannins and chromone derivatives [9]. Therapeutically, Syzygium genus is used in the treatment of rheumatism [10], haemorrhage, GIT disorders [11], diabetes [12], inflammation, allergy [13,14], convulsion [15], hypertension [16] and bacterial infections [17]. Despite its wide distribution, scientific research about S. campanulatum is scarce.…”