Moderate intervention with carotenoid-rich vegetable products reduces lipid peroxidation in men.
Because of their antioxidant properties, carotenoids may have beneficial effects in preventing cancer and cardiovascular disease. However, in humans consuming carotenoid-rich vegetables, data concerning the antioxidant effects of carotenoids are rather scarce. A human intervention trial was conducted, therefore, to determine whether a moderately increased consumption of carotenoid-rich vegetables would influence the antioxidant status in 23 healthy men. This short-term feeding study lasted 8 wk during which the men consumed a low carotenoid diet. A 2-wk low carotenoid period was followed by daily consumption of 330 mL tomato juice, then by 330 mL carrot juice and then by 10 g of spinach powder, each for 2 wk. Antioxidant status [water-soluble antioxidants in serum, ferric reducing ability of plasma (FRAP) and antioxidant enzyme activities] and lipid peroxidation (plasma malondialdehyde and ex vivo oxidation of LDL) were determined. In a subgroup of 10 men, lipoprotein carotenoids were measured. The consumption of carotenoid-rich vegetables significantly increased selected carotenoids in lipoproteins but had only minor effects on their relative distribution pattern. Tomato juice consumption reduced plasma thiobarbituric acid reactive substances (TBARS) by 12% (P: < 0.05) and lipoprotein oxidizability in terms of an increased lag time (18%, P: < 0.05). Carrot juice and spinach powder had no effect on lipid peroxidation. Water-soluble antioxidants, FRAP, glutathione peroxidase and reductase activities did not change during any study period. In evaluating the low carotenoid diet, we conclude that the additional consumption of carotenoid-rich vegetable products enhanced lipoprotein carotenoid concentrations, but only tomato juice reduced LDL oxidation in healthy men.
Bub
A
A
Institute of Nutritional Physiology, Federal Research Centre for Nutrition, D-76131 Karlsruhe, Germany.
Watzl
B
B
Abrahamse
L
L
Delincée
H
H
Adam
S
S
Wever
J
J
Müller
H
H
Rechkemmer
G
G
D000328:Adult; D000704:Analysis of Variance; D000975:Antioxidants / Q000378:metabolism*; D001205:Ascorbic Acid / Q000097:blood; D002338:Carotenoids / Q000008:administration & dosage / Q000032:analysis / Q000097:blood / Q000494:pharmacology*; D004032:Diet; D005504:Food Analysis; D005978:Glutathione / Q000097:blood; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects*; D008077:Lipoproteins, LDL / Q000032:analysis; D008297:Male; D014675:Vegetables
D000975:Antioxidants; D008077:Lipoproteins, LDL; D002338:Carotenoids; D005978:Glutathione; D001205:Ascorbic Acid