title: Daily consumption of grapefruit for 6 weeks reduces urine F2-isoprostanes in overweight adults with high baseline values but has no effect on plasma high-sensitivity C-reactive protein or soluble vascular cellular adhesion molecule 1.
abstract: Individuals with obesity and metabolic syndrome (MetS) are at increased risk of cardiovascular disease, in part due to heightened inflammatory/oxidative processes. Results from epidemiologic and experimental studies suggest that citrus, and grapefruit in particular, may have a role in promoting vascular health, although clinical trial data are lacking. Here, we evaluated the anti-inflammatory/antioxidant effects of habitual grapefruit consumption in 69 overweight/obese men and women and in a subsample of participants with MetS (n = 29). Participants were randomly assigned to either a grapefruit group in which they consumed a low bioactive diet plus 1.5 grapefruit/d for 6 wk (n = 37, n = 14 with MetS) or to a control condition in which a low bioactive diet devoid of citrus was consumed (n = 32, n = 15 with MetS). Plasma soluble vascular adhesion molecule-1 (sVCAM-1), plasma high-sensitivity C-reactive protein (hsCRP), and urinary F2-isoprostanes were evaluated before and after the intervention phase. F2-isoprostane concentrations were not different in the grapefruit versus control arm after the intervention (12.4 ± 6.4 vs. 15.9 ± 9.0 ng/mg creatinine, P = 0.16), whereas plasma hsCRP concentrations tended to be lower in the grapefruit versus control arm postintervention (2.1 ± 1.5 vs. 2.8 ± 2.0 mg/L, P = 0.09). In adults with MetS, grapefruit consumption tended to result in lower postintervention F2-isoprostane concentrations compared with the control condition (12.0 ± 4.5 vs. 18.3 ± 10.9 ng/mg creatinine, P = 0.06). Furthermore, those with high baseline F2-isoprostane concentrations experienced significant reductions in this biomarker in response to grapefruit consumption (P = 0.021). Change in sVCAM-1 concentrations did not vary by treatment arm nor were there differences between arms postintervention. These results suggest that intake of grapefruit twice daily for 6 wk does not significantly reduce inflammation and oxidative stress, although there is a suggestion of favorable modulation of oxidative stress in overweight and obese adults with MetS or those with high baseline urine F2-isoprostane concentrations.
authors.affiliation: Department of Nutritional Sciences.
authors.forename: Caitlin A
authors.initials: CA
authors.lastname: Dow
authors.forename: Betsy C
authors.initials: BC
authors.lastname: Wertheim
authors.forename: Bhimanagouda S
authors.initials: BS
authors.lastname: Patil
authors.forename: Cynthia A
authors.initials: CA
authors.lastname: Thomson
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000494:pharmacology / Q000627:therapeutic use; D015415:Biomarkers / Q000097:blood / Q000652:urine; D002097:C-Reactive Protein / Q000378:metabolism*; D002318:Cardiovascular Diseases / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control; D032083:Citrus paradisi; D028441:F2-Isoprostanes / Q000652:urine*; D005247:Feeding Behavior; D005260:Female; D005638:Fruit; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000178:diet therapy / Q000209:etiology; D008297:Male; D024821:Metabolic Syndrome / Q000150:complications / Q000178:diet therapy* / Q000378:metabolism; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000178:diet therapy* / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects*; D028321:Plant Preparations / Q000494:pharmacology; D019010:Vascular Cell Adhesion Molecule-1 / Q000097:blood*
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D028441:F2-Isoprostanes; D028321:Plant Preparations; D019010:Vascular Cell Adhesion Molecule-1; D002097:C-Reactive Protein
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