Incorporating freeze-dried strawberry powder into a high-fat meal does not alter postprandial vascular function or blood markers of cardiovascular disease risk: a randomized controlled trial

Abstract

Background: 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. Objective: This study was designed to investigate the effect of adding 40 g freeze-dried strawberry powder (w1 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. Design: Healthy, overweight or obese [mean 6 SEM body mass index (in kg/m 2 ): 31 6 0.5] adults (mean 6 SEM age: 28 6 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 w1 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. Results: 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. Conclusions: 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.Am J Clin Nutr 2017;105:313-22.

Attenuation of Postmeal Metabolic Indices with Red Raspberries in Individuals at Risk for Diabetes: A Randomized Controlled Trial

“…Several studies have examined the effects of berries on lipid metabolism after chronic intake , but few have examined the effects of berries or fruit phenolic compounds on postprandial TG metabolism. Previous studies have shown reduced mean postprandial TG with berry intake over 6 hours in people who are overweight with hyperlipidemia and no effect in healthy indivduals or individuals with insulin resistance . In the current study we found postprandial TG was not different with raspberry intake compared with Control.…”

The Postprandial Appearance of Features of Cardiometabolic Risk: Acute Induction and Prevention by Nutrients and Other Dietary Substances

“…Berries are rich in phytochemicals, and particularly phenolic compounds (2/3 flavonoids such as anthocyanins, catechins, quercetin, and kaempferol, and 1/3 phenolic acids such as ellagic acid), which are considered to be potent antioxidants inasmuch as they are able to scavenge ROS, chelate metal ions in vitro, and act synergistically between themselves and with micronutrients such as ascorbate and tocopherol [165,169,170]. The effects of berries on post-meal oxidative stress have been described in both the acute [171,172] and chronic settings [172]. In a chronic context, berries may exert anti-oxidative and anti-inflammatory effects by modulating mRNA expression in overweight and hypercholesterolemic individuals.…”

“…In the acute setting, the strawberry beverage (vs. the control) lowered postprandial increases in TG, HDL, and OxLDL at 3, 4, and 6 h after the meal. In the chronic setting, after a 6-week period, the strawberry beverage lowered mean cholesterol, LDL, TG, and OxLDL concentrations (when adjusted for fasting values) following the intake of a high-fat meal [172].…”

“…Again, adding a food/ingredient with a significant mass and energy (e.g., 500 mL juice) to a challenge meal tends to affect the kinetics of postprandial metabolism directly, and the results are therefore difficult to analyze. More recently, studies have used ingredients such as powders, and control treatments matched for macronutrient content, which is more useful when trying to ascribe the effects to polyphenolic fractions [172,187,195]. Second, studies have resorted to different postprandial endpoints and markers, in limited numbers, giving rise to highly fragmented findings.…”

Effects of Anthocyanins in Composite Meals on Cardiometabolic Outcomes—A Systematic Review of Randomized Controlled Feeding Trials

“…The characteristics of included articles are summarized in Table 1 . Overall, 18 articles were included in the systematic review, of which 8 were conducted in the United States of America [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ], 3 in Italy [ 24 , 25 , 26 ], 3 in the United Kingdom [ 12 , 27 , 28 ], and 2 in Chile [ 29 , 30 ]. One study each was conducted in Canada [ 31 ], and Austria [ 32 ].…”