Bioavailability of the dietary antioxidant flavonol quercetin in man.
Quercetin, a dietary antioxidant flavonoid, has anticarcinogenic properties. We quantified the absorption of quercetin in ileostomists. Absorption was 52 +/- 5% for quercetin glucosides from onions, 17 +/- 15% for quercetin rutinoside, and 24 +/- 9% for quercetin aglycone. The plasma quercetin concentration in subjects with an intact colon, after ingestion of fried onions, apples and pure quercetin rutinoside, decreased slowly with elimination half-lives of about 25 h. Thus, repeated dietary intake of quercetin will lead to accumulation in plasma. The relative bioavailability of quercetin from apples and rutinoside was one-third of that from onions. Absorption kinetics and bioavailibility might be determined by the type of glycoside. Dietary quercetin could increase the antioxidant capacity of blood plasma.
Hollman
P C
PC
DLO State Institute for Quality Control of Agricultural Products (RIKLIT-DLO), Wageningen, The Netherlands. p.c.h.hollman@rikilt.dlo.nl
van Trijp
J M
JM
Mengelers
M J
MJ
de Vries
J H
JH
Katan
M B
MB
D000490:Allium / Q000378:metabolism; D016588:Anticarcinogenic Agents / Q000097:blood*; D000975:Antioxidants / Q000378:metabolism*; D001682:Biological Availability; D005638:Fruit / Q000378:metabolism; D006801:Humans; D011794:Quercetin / Q000097:blood*; D013997:Time Factors
D016588:Anticarcinogenic Agents; D000975:Antioxidants; D011794:Quercetin