title: Effects of short-term walnut consumption on human microvascular function and its relationship to plasma epoxide content.
abstract: Improved vascular function after the incorporation of walnuts into controlled or high-fat diets has been reported; however, the mechanism(s) underlying this effect of walnuts is(are) poorly defined. The objective of the current study was to evaluate the acute and short-term effects of walnut intake on changes in microvascular function and the relationship of these effects to plasma epoxides, the cytochrome-P450-derived metabolites of fatty acids. Thirty-eight hypercholesterolemic postmenopausal women were randomized to 4 weeks of 5 g or 40 g of daily walnut intake. All outcomes were measured after an overnight fast and 4 h after walnut intake. Microvascular function, assessed as the reactive hyperemia index (RHI), was the primary outcome measure, with serum lipids and plasma epoxides as secondary measures. Compared to 5 g of daily walnut intake, consuming 40 g/d of walnuts for 4 weeks increased the RHI and Framingham RHI. Total cholesterol and low- and high-density cholesterol did not significantly change after walnut intake. The change in RHI after 4 weeks of walnut intake was associated with the change in the sum of plasma epoxides (r=0.65, P=.002) but not with the change in the sum of plasma hydroxyeicosatetraenoic acids. Of the individual plasma epoxides, arachidonic-acid-derived 14(15)-epoxyeicosatrienoic acid was most strongly associated with the change in microvascular function (r=0.72, P<.001). These data support the concept that the intake of walnut-derived fatty acids can favorably affect plasma epoxide production, resulting in improved microvascular function.
authors.affiliation: Department of Nutrition, University of California, Davis, One Shields Avenue, Davis CA, 95616, USA. Electronic address: rrholt@ucdavis.edu.
authors.forename: Roberta R
authors.initials: RR
authors.lastname: Holt
authors.affiliation: Department of Nutrition, University of California, Davis, One Shields Avenue, Davis CA, 95616, USA.
authors.forename: Sun J
authors.initials: SJ
authors.lastname: Yim
authors.affiliation: Cardiovascular Health Research Center, Sanford Research/USD 2301 E 60th St N, Sioux Falls SD 57104; Department of Internal Medicine, Sanford School of Medicine, University of South Dakota, 1400 West 22nd Street, Sioux Falls, SD 57105; Department of Nutritional Sciences, The Pennsylvania State University, 110 Chandlee Laboratory, University Park PA, 16802, USA.
authors.forename: Gregory C
authors.initials: GC
authors.lastname: Shearer
authors.affiliation: Department of Nutrition, University of California, Davis, One Shields Avenue, Davis CA, 95616, USA.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Hackman
authors.affiliation: Department of Nutrition, University of California, Davis, One Shields Avenue, Davis CA, 95616, USA.
authors.forename: Dragana
authors.initials: D
authors.lastname: Djurica
authors.affiliation: Department of Nutrition, University of California, Davis, One Shields Avenue, Davis CA, 95616, USA; United States Department of Agriculture, Western Human Nutrition Research Center, 430 West Health Sciences Drive, Davis CA, 95616, USA.
authors.forename: John W
authors.initials: JW
authors.lastname: Newman
authors.affiliation: Department of Urology, University of California, Davis Medical Center, 4860 Y. Street, Suite 3500, Sacramento CA, 95817, USA.
authors.forename: Alan W
authors.initials: AW
authors.lastname: Shindel
authors.affiliation: Department of Nutrition, University of California, Davis, One Shields Avenue, Davis CA, 95616, USA; Department of Internal Medicine, University of California, Davis Medical Center, 4150 V. Street, Suite 3100, Sacramento CA, 95817, USA.
authors.forename: Carl L
authors.initials: CL
authors.lastname: Keen
mesh_terms: D000368:Aged; D016718:Arachidonic Acid / Q000737:chemistry; D008076:Cholesterol, HDL / Q000378:metabolism; D008078:Cholesterol, LDL / Q000378:metabolism; D004032:Diet; D059305:Diet, High-Fat; D004852:Epoxy Compounds / Q000097:blood*; D005227:Fatty Acids / Q000097:blood / Q000378:metabolism; D005260:Female; D006801:Humans; D006937:Hypercholesterolemia / Q000378:metabolism; D006940:Hyperemia / Q000378:metabolism; D031324:Juglans; D019787:Linoleic Acid / Q000097:blood; D008055:Lipids / Q000097:blood; D008074:Lipoproteins / Q000097:blood; D008833:Microcirculation / Q000502:physiology*; D008875:Middle Aged; D009754:Nuts; D054883:Oxylipins / Q000097:blood / Q000378:metabolism
chemical_list: D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D004852:Epoxy Compounds; D005227:Fatty Acids; D008055:Lipids; D008074:Lipoproteins; D054883:Oxylipins; D016718:Arachidonic Acid; D019787:Linoleic Acid
keywords: Linoleic acid; Oxylipin; Vascular function; Walnuts; alpha-Linolenic acid