Influence of increased fruit and vegetable intake on plasma and lipoprotein carotenoids and LDL oxidation in smokers and nonsmokers

Citation
M. Chopra et al., Influence of increased fruit and vegetable intake on plasma and lipoprotein carotenoids and LDL oxidation in smokers and nonsmokers, CLIN CHEM, 46(11), 2000, pp. 1818-1829
Citations number
41
Categorie Soggetti
Medical Research Diagnosis & Treatment
Journal title
CLINICAL CHEMISTRY
ISSN journal
00099147 → ACNP
Volume
46
Issue
11
Year of publication
2000
Pages
1818 - 1829
Database
ISI
SICI code
0009-9147(200011)46:11<1818:IOIFAV>2.0.ZU;2-G
Abstract
Background Epidemiological studies suggest a cardioprotective role for caro tenoid-rich foods. Smokers have a high risk of cardiovascular disease and l ow dietary intake and plasma concentrations of carotenoids. The aim of this study was to determine the carotenoid response of smokers and nonsmokers t o increased intake of 300-400 g of vegetables and its effect on LDL oxidati on. Methods: After a depletion period of 8 days, 34 healthy females (18 nonsmok ers, 16 smokers) were supplemented with beta -carotene- and lutein-rich (gr een) and lycopene-rich (red) vegetable foods, each for 7 days. Results: Baseline concentrations (mean a SD) of plasma beta -carotene (0.20 3 a 0.28 mu mol/L vs 0.412 +/- 0.34 mu mol/L; P <0.005) and lutein (0.180 /- 0.10 vs 0.242 +/- 0.11 <mu>mol/L; P <0.05) but not lycopene (0.296 +/- 0 .10 vs 0.319 +/- 0.33 <mu>mol/L) were significantly lower in smokers compar ed with nonsmokers. After supplementation, the change (supplementation minu s depletion) in plasma beta -carotene (0.152 +/- 0.43 vs 0.363 +/- 0.29 mu mol/L in smokers vs nonsmokers; P = 0.002) and LDL lutein (0.015 +/- 0.03 v s 0.029 +/- 0.03 mu mol/mmol cholesterol; P = 0.01) was significantly lower in smokers than nonsmokers. Green-vegetable supplementation had no effect on the resistance of LDL to oxidation (lag-phase) in either group. After re d-vegetable supplementation, plasma and LDL lycopene concentrations were in creased in both groups, but only nonsmokers showed a significant increase i n the lag-phase (44.9 +/- 9.5 min at baseline, 41.4 a 6.5 min after depleti on, and 49.0 a 8.9 min after supplementation; P <0.01) compared with deplet ion. Conclusions: In this short-term intervention study, a dietary intake of >40 mg/day of lycopene by a group of nonsmoking individuals significantly redu ced the susceptibility of LDL to oxidation, whereas an equivalent increase in lycopene by a group of smokers showed no such effect. (C) 2000 American Association for Clinical Chemistry.