Polyphenol-rich phloem enhances the resistance of total serum lipids to oxidation in men.
In humans, polyphenol supplementation studies have resulted in inconsistent findings in lipid peroxidation. Our aim was to investigate the effects of a 4-week consumption of polyphenol-rich phloem on serum lipids and lipid peroxidation in the hydrophilic fraction of serum and on isolated lipoproteins. We conducted a randomized double-blind supplementation study consisting of 75 nonsmoking hypercholesterolemic men. Participants consumed 70 g daily of either rye bread (placebo) or phloem-fortified rye bread containing 31 mg (low polyphenol, LP) or 62 mg (high polyphenol, HP) of catechins. The ex vivo susceptibility of total serum lipids and VLDL and LDL to oxidation after copper induction was measured as a lag time to the maximal oxidation rate at the baseline and after the supplementation. In the HP group, an increase in the oxidation resistance of total serum lipids was observed (11.4%), while no effect was seen in the LP group (-0.8%) or in the placebo group (-1.0%) (p = 0.007). No differences were observed in the oxidation resistance of VLDL and LDL between the study groups. The phloem also increased in vitro oxidation resistance of serum lipids and radical scavenging activity (DPPH.) in a dose-dependent manner. Our results suggest that polyphenols may inhibit lipid peroxidation in the hydrophilic fraction of serum.
Mursu
Jaakko
J
Research Institute of Public Health, University of Kuopio, Kuopio, Finland. jaakko.mursu@uku.fi
Voutilainen
Sari
S
Nurmi
Tarja
T
Helleranta
Meri
M
Rissanen
Tiina H
TH
Nurmi
Anna
A
Kaikkonen
Jari
J
Porkkala-Sarataho
Elina
E
Nyyssönen
Kristiina
K
Virtanen
Jyrki K
JK
Salonen
Riitta
R
Salonen
Jukka T
JT
D000328:Adult; D000368:Aged; D001939:Bread; D003300:Copper / Q000494:pharmacology; D004311:Double-Blind Method; D005419:Flavonoids / Q000008:administration & dosage* / Q000032:analysis; D005527:Food, Fortified; D006801:Humans; D006937:Hypercholesterolemia / Q000097:blood; D015227:Lipid Peroxidation / Q000187:drug effects; D008055:Lipids / Q000097:blood*; D008077:Lipoproteins, LDL / Q000097:blood; D008079:Lipoproteins, VLDL / Q000097:blood; D008297:Male; D008875:Middle Aged; D010636:Phenols / Q000008:administration & dosage* / Q000032:analysis; D028223:Pinus / Q000737:chemistry*; D010919:Placebos; D024301:Plant Bark / Q000737:chemistry*; D059808:Polyphenols; D012434:Secale
D005419:Flavonoids; D008055:Lipids; D008077:Lipoproteins, LDL; D008079:Lipoproteins, VLDL; D010636:Phenols; D010919:Placebos; D059808:Polyphenols; D003300:Copper