Strawberry anthocyanin and its association with postprandial inflammation and insulin

Abstract

The present study investigates the effect of strawberry antioxidants in beverage form on meal-induced postprandial inflammatory and insulin responses in human subjects. Overweight adults (n 24) consumed a high-carbohydrate, moderate-fat meal (HCFM) accompanied by either a strawberry or a placebo beverage in a cross-over design. Postprandial changes in plasma anthocyanins, their metabolites, insulin, glucose and inflammatory markers were assessed for 6 h. The postprandial concentrations of pelargonidin sulfate and pelargonidin-3-O-glucoside were significantly increased when the strawberry beverage was consumed concurrently with the HCFM compared with the placebo beverage (P,0·001). The strawberry beverage significantly attenuated the postprandial inflammatory response as measured by high-sensitivity C-reactive protein and IL-6 (P,0·05) induced by the HCFM. It was also associated with a reduction in postprandial insulin response (P,0·05). Collectively, these data provide evidence for favourable effects of strawberry antioxidants on postprandial inflammation and insulin sensitivity.

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

“…It is unclear why our results differ from the significant reductions in postprandial insulin (27,28), as well as triglycerides and oxidized LDL (26), found in the 2 previous postprandial strawberry studies. Dairy proteins and the timing of meal intake may diminish the effects of polyphenols (56,57); however, significant benefits have been achieved with the use of a milkbased beverage consumed with a test meal (26,28).…”

“…Although the amount of strawberries required to optimize effects on clinical outcomes is unknown, our 40-g dose of freeze-dried powder was equivalent to w3 cups of fresh strawberries [13 g freeze-dried powder is equivalent to 1 cup fresh (C Christian California Strawberry Commission, personal communication, 2014)] and provided a substantial amount of polyphenols (Supplemental Table 2). A similar amount of total anthocyanins was provided in the postprandial study by Park et al (28), although the freeze-dried strawberry powder used by BurtonFreeman and colleagues (26,27) had a higher oxygen radical absorbance capacity value and a higher concentration of select polyphenolic compounds, including quercetin and pelargonidin-3-glucoside. These differences may account, in part, for the discrepancies between our results and those of Burton-Freeman et al (26).…”

“…Longerterm strawberry supplementation has been shown to improve multiple CVD risk factors (16)(17)(18)(19)(20)(21)(22)(23)(24)(25), but less is known about the acute effects of strawberries in the context of a fat-containing meal. A modest attenuation of the 6-h postprandial triglyceride, insulin, and oxidized LDL response was found in overweight hyperlipidemic adults when 10 g freeze-dried strawberry powder was incorporated into a meal with 30 g total fat (26,27). In a subsequent study, incorporating 40 g freeze-dried strawberry powder into a high-carbohydrate meal with 25 g total fat significantly reduced the 6-h insulin response in individuals with insulin resistance, but had no effect on postprandial glucose, triglycerides, or oxidized LDL (28).…”

Effect of grape seed extract on postprandial oxidative status and metabolic responses in men and women with the metabolic syndrome - randomized, cross-over, placebo-controlled study

“…We, along with others, have shown that consumption of a meal that is high in readily available carbohydrates and fat results in an increase in markers of oxidative stress and inflammation postprandially [8][9][10][11][12][13]. These changes are accentuated in obesity, diabetes and individuals with the MetS [14].…”

“…Fruits and vegetables, particularly those with higher polyphenolic content, have favorable effects on human health due to their ability to modulate oxidative and inflammatory stress in peripheral tissues [12,13,15]. These effects have also been associated with improvements in insulin sensitivity [16] and postprandial insulin responses [9]. Grape seeds are a concentrated source of polyphenols and have received considerable attention for their antioxidant capacity and biological effects after chronic consumption [17][18][19][20].…”