Effect of raisin consumption on oxidative stress and inflammation in obesity.
OBJECTIVE
Oxidative stress can initiate increased inflammation that elevates risk for cardiovascular disease. The objective of this study was to determine the effects of daily consumption of raisins on markers of oxidative stress, inflammation and endothelial activation in response to an acute high-fat meal in overweight individuals.


METHODS
Seventeen overweight men and women consumed 90 g raisins or isocaloric placebo (264 kcal/day) for 14 days in a randomized, crossover design while following a low-flavonoid diet. The oxidative [urinary 8-iso-prostaglandin-F(2alpha) (8-epi PGF(2alpha)) and serum oxygen radical absorbance capacity (ORAC)], inflammatory (serum C-reactive protein and interleukin-6), endothelial (serum soluble intercellular adhesion molecule-1 and soluble vascular cell adhesion molecule-1, sVCAM-1) and metabolic [free fatty acids (FFAs), triacylglycerol, glucose and insulin] response to four high-fat (53%) meals was tested pre- and postintervention.


RESULTS
Urinary 8-epi PGF(2alpha) decreased (-22%) and fasting ORAC increased (+3%) after both interventions combined. Fasting protein-free ORAC was modestly (+3.5%) higher during the raisin than the placebo intervention. Neither the meals nor the raisins consistently induced fasted markers of inflammation or endothelial dysfunction. Gender influenced postprandial metabolic responses in that males responded with higher serum FFAs, sVCAM-1 and glucose compared with females.


CONCLUSIONS
Serum antioxidant capacity was modestly increased by daily raisin consumption, but this did not alter fasted or postprandial inflammatory response in these relatively healthy but overweight individuals. Providing all food in regular pattern reduced measures of oxidative stress.
Rankin
J W
JW
Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA 24061-0430, USA. jrankin@vt.edu
Andreae
M C
MC
Oliver Chen
C-Y
CY
O'Keefe
S F
SF
D000328:Adult; D000704:Analysis of Variance; D015415:Biomarkers / Q000097:blood / Q000652:urine; D001786:Blood Glucose / Q000032:analysis; D002097:C-Reactive Protein / Q000032:analysis; D018592:Cross-Over Studies; D004038:Diet, Reducing; D015237:Dinoprost / Q000031:analogs & derivatives / Q000652:urine; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D007249:Inflammation / Q000178:diet therapy; D018799:Intercellular Adhesion Molecule-1 / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D009765:Obesity / Q000178:diet therapy* / Q000276:immunology / Q000378:metabolism; D018384:Oxidative Stress; D008517:Phytotherapy; D019518:Postprandial Period; D012737:Sex Factors; D019010:Vascular Cell Adhesion Molecule-1 / Q000097:blood; D027843:Vitis; D055815:Young Adult
D015415:Biomarkers; D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D015850:Interleukin-6; D019010:Vascular Cell Adhesion Molecule-1; D018799:Intercellular Adhesion Molecule-1; C075750:8-epi-prostaglandin F2alpha; D002097:C-Reactive Protein; D015237:Dinoprost