Richter Chesney K, Skulas-Ray Ann C, Gaugler Trent L, Lambert Joshua D, Proctor David N, Kris-Etherton Penny M
Department of Nutritional Sciences.
Department of Mathematics, Lafayette College, Easton, PA.
Am J Clin Nutr. 2017 Feb;105(2):313-322. doi: 10.3945/ajcn.116.141804. Epub 2016 Dec 21.
Postprandial dysmetabolism-an exaggerated spike in triglycerides, glucose, and insulin-increases cardiovascular disease risk by inducing oxidative stress, inflammation, and endothelial dysfunction. Polyphenol-rich foods may blunt these effects when they are incorporated into a high-fat, calorie-dense meal. Strawberries are a rich source of polyphenols, but there is little research on their postprandial effects.
This study was designed to investigate the effect of adding 40 g freeze-dried strawberry powder (∼1 lb. or 0.45 kg fresh strawberries) to a high-fat (50 g total fat) meal on postprandial vascular function, as well as triglyceride, glucose, and insulin responses.
Healthy, overweight or obese [mean ± SEM body mass index (in kg/m): 31 ± 0.5] adults (mean ± SEM age: 28 ± 2 y; 17 men and 13 women) consumed a control meal and a strawberry meal in a randomized crossover design. Testing sessions were separated by ≥1 wk for men and ∼1 mo for women to control for hormonal variations. Blood samples were obtained before the meal and 0.5, 1, 2, and 4 h after the meal. Central blood pressure and arterial stiffness indexes were measured at baseline and 2 and 4 h postmeal with the use of pulse waveform analysis.
There were no significant differences between the strawberry and control meals for any outcomes. Consumption of either meal significantly decreased the augmentation index at 2 and 4 h (P < 0.002) and significantly increased triglycerides, insulin, and glucose at all time points (P < 0.001) relative to baseline.
The strawberry intervention did not alter vascular function or attenuate postprandial metabolic derangements in triglycerides, glucose, or insulin relative to the control meal. Additional research is needed to clarify whether strawberries or other polyphenol-rich interventions improve postprandial responses, and future studies should take into account the acute meal-induced improvements in measures of vascular function. This trial was registered at clinicaltrials.gov as NCT01989637.
餐后代谢紊乱——甘油三酯、葡萄糖和胰岛素的过度峰值——通过诱导氧化应激、炎症和内皮功能障碍增加心血管疾病风险。富含多酚的食物在纳入高脂肪、高热量饮食时可能会减轻这些影响。草莓是多酚的丰富来源，但关于其餐后效应的研究很少。
本研究旨在调查在高脂肪（总脂肪50克）餐中添加40克冻干草莓粉（约1磅或0.45千克新鲜草莓）对餐后血管功能以及甘油三酯、葡萄糖和胰岛素反应的影响。
健康、超重或肥胖[平均±标准误体重指数（千克/米²）：31±0.5]的成年人（平均±标准误年龄：28±2岁；17名男性和13名女性）采用随机交叉设计食用对照餐和草莓餐。男性测试时段间隔≥1周，女性间隔约1个月，以控制激素变化。在餐前以及餐后0.5、1、2和4小时采集血样。使用脉搏波形分析在基线以及餐后2和4小时测量中心血压和动脉僵硬度指数。
草莓餐和对照餐在任何结果方面均无显著差异。相对于基线，食用任何一餐在餐后2和4小时均显著降低增强指数（P<0.002），并在所有时间点显著增加甘油三酯、胰岛素和葡萄糖（P<0.001）。
相对于对照餐，草莓干预未改变血管功能，也未减轻餐后甘油三酯、葡萄糖或胰岛素的代谢紊乱。需要进一步研究以阐明草莓或其他富含多酚的干预措施是否能改善餐后反应，未来的研究应考虑到急性餐食引起的血管功能测量指标的改善。本试验在clinicaltrials.gov上注册，注册号为NCT01989637。
