Basu Arpita, Wilkinson Marci, Penugonda Kavitha, Simmons Brandi, Betts Nancy M, Lyons Timothy J
Department of Nutritional Sciences, 301 Human Environmental Sciences, Oklahoma State University, Stillwater, OK 74078, USA.
Nutr J. 2009 Sep 28;8:43. doi: 10.1186/1475-2891-8-43.
Strawberry flavonoids are potent antioxidants and anti-inflammatory agents that have been shown to reduce cardiovascular disease risk factors in prospective cohort studies. Effects of strawberry supplementation on metabolic risk factors have not been studied in obese populations. We tested the hypothesis that freeze-dried strawberry powder (FSP) will lower fasting lipids and biomarkers of oxidative stress and inflammation at four weeks compared to baseline. We also tested the tolerability and safety of FSP in subjects with metabolic syndrome. FSP is a concentrated source of polyphenolic flavonoids, fiber and phytosterols.
Females (n = 16) with 3 features of metabolic syndrome (waist circumference >35 inches, triglycerides > 150 mg/dL, fasting glucose > 100 mg/dL and < 126 mg/dL, HDL <50 mg/dL, or blood pressure >130/85 mm Hg) were enrolled in the study. Subjects consumed two cups of the strawberry drink daily for four weeks. Each cup had 25 g FSP blended in water. Fasting blood draws, anthropometrics, dietary analyses, and blood pressure measurements were done at baseline and 4 weeks. Biomarkers of oxidative stress and inflammation were measured using ELISA techniques. Plasma ellagic acid was measured using HPLC-UV techniques.
Total cholesterol and LDL-cholesterol levels were significantly lower at 4 weeks versus baseline (-5% and -6%, respectively, p < 0.05), as was lipid peroxidation in the form of malondialdehyde and hydroxynonenal (-14%, p < 0.01). Oxidized-LDL showed a decreasing trend at 4 weeks (p = 0.123). No effects were noted on markers of inflammation including C-reactive protein and adiponectin. A significant number of subjects (13/16) showed an increase in plasma ellagic acid at four weeks versus baseline, while no significant differences were noted in dietary intakes at four weeks versus baseline. Thus, short-term supplementation of freeze-dried strawberries appeared to exert hypocholesterolemic effects and decrease lipid peroxidation in women with metabolic syndrome.
草莓类黄酮是强效抗氧化剂和抗炎剂，在前瞻性队列研究中已显示可降低心血管疾病风险因素。在肥胖人群中尚未研究补充草莓对代谢风险因素的影响。我们检验了以下假设：与基线相比，冻干草莓粉（FSP）在四周后将降低空腹血脂以及氧化应激和炎症的生物标志物。我们还测试了FSP在代谢综合征患者中的耐受性和安全性。FSP是多酚类黄酮、纤维和植物甾醇的浓缩来源。
纳入具有代谢综合征3项特征（腰围>35英寸、甘油三酯>150mg/dL、空腹血糖>100mg/dL且<126mg/dL、高密度脂蛋白<50mg/dL或血压>130/85mmHg）的女性（n = 16）参与研究。受试者每天饮用两杯草莓饮料，持续四周。每杯含有25g混入水中的FSP。在基线和4周时进行空腹采血、人体测量、饮食分析和血压测量。使用酶联免疫吸附测定（ELISA）技术测量氧化应激和炎症的生物标志物。使用高效液相色谱-紫外（HPLC-UV）技术测量血浆鞣花酸。
与基线相比，4周时总胆固醇和低密度脂蛋白胆固醇水平显著降低（分别降低5%和6%，p<0.05），以丙二醛和羟基壬烯醛形式存在的脂质过氧化水平也显著降低（降低14%，p<0.01）。4周时氧化型低密度脂蛋白呈下降趋势（p = 0.123）。未观察到对包括C反应蛋白和脂联素在内的炎症标志物有影响。与基线相比，大量受试者（13/16）在4周时血浆鞣花酸增加，而4周时与基线相比饮食摄入量无显著差异。因此，短期补充冻干草莓似乎对代谢综合征女性具有降胆固醇作用并减少脂质过氧化。
