title: Acute consumption of walnuts and walnut components differentially affect postprandial lipemia, endothelial function, oxidative stress, and cholesterol efflux in humans with mild hypercholesterolemia.
abstract: Walnut consumption improves cardiovascular disease risk; however, to our knowledge, the contribution of individual walnut components has not been assessed. This study evaluated the acute consumption of whole walnuts (85 g), separated nut skins (5.6 g), de-fatted nutmeat (34 g), and nut oil (51 g) on postprandial lipemia, endothelial function, and oxidative stress. Cholesterol efflux (ex vivo) was assessed in the whole walnut treatment only. A randomized, 4-period, crossover trial was conducted in healthy overweight and obese adults (n = 15) with moderate hypercholesterolemia. There was a treatment × time point interaction for triglycerides (P < 0.01) and increased postprandial concentrations were observed for the oil and whole walnut treatments (P < 0.01). Walnut skins decreased the reactive hyperemia index (RHI) compared with baseline (P = 0.02) such that a difference persisted between the skin and oil treatments (P = 0.01). The Framingham RHI was maintained with the oil treatment compared with the skins and whole nut (P < 0.05). There was a treatment effect for the ferric reducing antioxidant potential (FRAP) (P < 0.01), and mean FRAP was greater with the oil and skin treatments compared with the nutmeat (P < 0.01). Cholesterol efflux increased by 3.3% following whole walnut consumption in J774 cells cultured with postprandial serum compared with fasting baseline (P = 0.02). Walnut oil favorably affected endothelial function and whole walnuts increased cholesterol efflux. These 2 novel mechanisms may explain in part the cardiovascular benefits of walnuts.
authors.affiliation: Department of Nutritional Sciences, The Pennsylvania State University, University Park, PA, USA.
authors.forename: Claire E
authors.initials: CE
authors.lastname: Berryman
authors.forename: Jessica A
authors.initials: JA
authors.lastname: Grieger
authors.forename: Sheila G
authors.initials: SG
authors.lastname: West
authors.forename: Chung-Yen O
authors.initials: CY
authors.lastname: Chen
authors.forename: Jeffrey B
authors.initials: JB
authors.lastname: Blumberg
authors.forename: George H
authors.initials: GH
authors.lastname: Rothblat
authors.forename: Sandhya
authors.initials: S
authors.lastname: Sankaranarayanan
authors.forename: Penny M
authors.initials: PM
authors.lastname: Kris-Etherton
mesh_terms: D000328:Adult; D002460:Cell Line; D002784:Cholesterol / Q000097:blood / Q000378:metabolism; D004032:Diet; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins; D004730:Endothelium, Vascular / Q000503:physiopathology; D002149:Energy Intake; D005260:Female; D006339:Heart Rate; D006801:Humans; D006937:Hypercholesterolemia / Q000097:blood / Q000503:physiopathology*; D031324:Juglans; D008055:Lipids / Q000097:blood; D008264:Macrophages / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009754:Nuts; D009765:Obesity / Q000503:physiopathology; D050177:Overweight / Q000503:physiopathology; D018384:Oxidative Stress / Q000502:physiology; D019518:Postprandial Period
chemical_list: D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins; D008055:Lipids; D002784:Cholesterol