TY - JOUR

T1 - β-Carotene does not change markers of enzymatic and nonenzymatic antioxidant activity in human blood

AU - Castenmiller, Jacqueline J M

AU - Lauridsen, Søren T

AU - Dragsted, Lars Ove

AU - van Het Hof, Karin

AU - Linssen, Jozef P H

AU - West, Clive E

N1 - (Ekstern)

PY - 1999

Y1 - 1999

N2 - In vitamin A-replete populations, increased concentrations of serum carotenoids have been associated with a decreased risk of degenerative diseases. The mechanism of action of carotenoids in determining antioxidant activity is largely unknown. The aim of the study was to examine the effect of carotenoid supplementation and spinach intake on erythrocyte enzyme antioxidant activities, serum or plasma nonenzymatic antioxidant concentrations, and concentrations of oxidatively damaged amino acids in plasma. Subjects received for 3 wk a basic diet (n = 10), a basic diet with a carotenoid supplement (n = 12) or with a spinach product (n 12 per group), i.e., whole-leaf, minced, liquefied or liquefied spinach plus added dietary fiber. After 3 wk of dietary intervention, changes in serum or plasma concentrations of ascorbic acid, α-tocopherol, FRAP (ferric reducing ability of plasma) and uric acid and erythrocyte enzyme activities were assessed, and differences among experimental groups were tested. Consumption of spinach resulted in greater (P < 0.01) erythrocyte glutathione reductase activity and lower (P < 0.05) erythrocyte catalase activity and serum α-tocopherol concentration compared with the control group. Consumption of the carotenoid supplement led to lower α-tocopherol responses (P = 0.02) compared with the basic diet only. Our data suggest that the short-term changes in erythrocyte glutathione reductase activity and serum α-tocopherol concentration can be attributed to an increased carotenoid (lutein and zeaxanthin) intake, but β- carotene is unlikely to be a causative factor. Lower erythrocyte catalase activity after intervention with spinach products may be related to other constituents in spinach such as flavonoids.

AB - In vitamin A-replete populations, increased concentrations of serum carotenoids have been associated with a decreased risk of degenerative diseases. The mechanism of action of carotenoids in determining antioxidant activity is largely unknown. The aim of the study was to examine the effect of carotenoid supplementation and spinach intake on erythrocyte enzyme antioxidant activities, serum or plasma nonenzymatic antioxidant concentrations, and concentrations of oxidatively damaged amino acids in plasma. Subjects received for 3 wk a basic diet (n = 10), a basic diet with a carotenoid supplement (n = 12) or with a spinach product (n 12 per group), i.e., whole-leaf, minced, liquefied or liquefied spinach plus added dietary fiber. After 3 wk of dietary intervention, changes in serum or plasma concentrations of ascorbic acid, α-tocopherol, FRAP (ferric reducing ability of plasma) and uric acid and erythrocyte enzyme activities were assessed, and differences among experimental groups were tested. Consumption of spinach resulted in greater (P < 0.01) erythrocyte glutathione reductase activity and lower (P < 0.05) erythrocyte catalase activity and serum α-tocopherol concentration compared with the control group. Consumption of the carotenoid supplement led to lower α-tocopherol responses (P = 0.02) compared with the basic diet only. Our data suggest that the short-term changes in erythrocyte glutathione reductase activity and serum α-tocopherol concentration can be attributed to an increased carotenoid (lutein and zeaxanthin) intake, but β- carotene is unlikely to be a causative factor. Lower erythrocyte catalase activity after intervention with spinach products may be related to other constituents in spinach such as flavonoids.

KW - Antioxidants

KW - Carotenoids

KW - Humans

KW - Spinach

KW - α-tocopherol

UR - http://www.scopus.com/inward/record.url?scp=0032701776&partnerID=8YFLogxK

U2 - 10.1093/jn/129.12.2162

DO - 10.1093/jn/129.12.2162

M3 - Journal article

C2 - 10573544

AN - SCOPUS:0032701776

VL - 129

SP - 2162

EP - 2169

JO - Journal of Nutrition

JF - Journal of Nutrition

SN - 0022-3166

IS - 12

ER -