title: Polyphenol-rich phloem enhances the resistance of total serum lipids to oxidation in men.
abstract: 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.
authors.affiliation: Research Institute of Public Health, University of Kuopio, Kuopio, Finland. jaakko.mursu@uku.fi
authors.forename: Jaakko
authors.initials: J
authors.lastname: Mursu
authors.forename: Sari
authors.initials: S
authors.lastname: Voutilainen
authors.forename: Tarja
authors.initials: T
authors.lastname: Nurmi
authors.forename: Meri
authors.initials: M
authors.lastname: Helleranta
authors.forename: Tiina H
authors.initials: TH
authors.lastname: Rissanen
authors.forename: Anna
authors.initials: A
authors.lastname: Nurmi
authors.forename: Jari
authors.initials: J
authors.lastname: Kaikkonen
authors.forename: Elina
authors.initials: E
authors.lastname: Porkkala-Sarataho
authors.forename: Kristiina
authors.initials: K
authors.lastname: Nyyssönen
authors.forename: Jyrki K
authors.initials: JK
authors.lastname: Virtanen
authors.forename: Riitta
authors.initials: R
authors.lastname: Salonen
authors.forename: Jukka T
authors.initials: JT
authors.lastname: Salonen
mesh_terms: 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
chemical_list: D005419:Flavonoids; D008055:Lipids; D008077:Lipoproteins, LDL; D008079:Lipoproteins, VLDL; D010636:Phenols; D010919:Placebos; D059808:Polyphenols; D003300:Copper