Effects of dietary strawberry powder on blood lipids and inflammatory markers in obese human subjects

Abstract

Obesity is a strong risk factor for the development of CVD, hypertension and type 2 diabetes. The overall goal of the present pilot study was to feed strawberries, in the form of freeze-dried powder, to obese subjects to determine whether dietary strawberries beneficially altered lipid profiles and reduced blood markers of inflammation compared with a control intervention. A total of twenty healthy subjects (thirteen females and seven males) aged between 20 and 50 years with a BMI between 30 and 40 kg/m 2 completed the present 7-week double-blind, randomised, cross-over trial. Each subject received a prepared diet 7 d/week for 7 weeks consisting of approximately 35 % of energy from fat, 20 % protein, 45 % carbohydrate and 14 g fibre. Blood was collected on days 1 and 8 for baseline information. After the first week, subjects were randomly assigned to the strawberry powder (equivalent to four servings of frozen strawberries) or control (strawberry-flavoured) intervention for 3 weeks. For the remaining 3 weeks, subjects crossed over to the opposite intervention. Blood was collected again at the end of weeks 3, 4, 6 and 7. A comprehensive chemistry panel, lipid profile analyses and measurement of inflammatory mediators were performed for each blood draw. A 3-week dietary intervention with strawberry powder reduced plasma concentrations of cholesterol and small HDL-cholesterol particles, and increased LDL particle size in obese subjects (P, 0·05). Dietary strawberry powder reduced risk factors for CVD, stroke and diabetes in obese volunteers, suggesting a potential role for strawberries as a dietary means to decrease obesity-related disease.

Effects of Freeze-Dried Strawberry Supplementation on Metabolic Biomarkers of Atherosclerosis in Subjects with Type 2 Diabetes: A Randomized Double-Blind Controlled Trial

“…In order to provide a concentrated source of polyphones, fiber and micronutrients (table 2) for subjects with T2D, 50 g of FDS, equivalent to 500 g of fresh strawberries or 2 servings of fresh strawberries, was selected as a daily supplement for a period of 6 weeks. The supplement dose was obtained according to previous studies that demonstrated cardiovascular health benefits and compliance with dosing of 50 g of FDS [19,20,21,22,23]. The prescribed dose was also based on the benefits of adding at least two servings of fruits with low glycemic index to the dietary plan of patients with diabetes [24].…”

“…Results from Wilson et al [30] and DeFuria et al [31] postprandial researches might provide more evidence for the latter metabolic mechanisms. Though results from studies which had investigated the effects of FDS on metabolic features of obese, hyperlipidemic subjects or subjects with metabolic syndrome revealed no significant changes in serum glucose concentration [19,20,21,22,23]. In previous studies the effect of FDS on glycated Hb was not investigated due to the shorter intervention period, lesser sample size and subjects having metabolic complications other than diabetes.…”

“…According to the Women Health Study, strawberry consumption (>2 servings per week) significantly reduced the likelihood of an elevated CRP (≥3 mg/l) [33]. However, Zunino et al [20] found no significant reduction in inflammatory markers after strawberry powder supplementation for 3 weeks in obese subjects, which might be due to a shorter period of intervention. Moreover, in the studies conducted by Basu et al [22] and Jenkins et al [23] the changes in inflammatory markers following FDS supplementation for 4 weeks were not significant, which might be due to a smaller sample size and a shorter intervention period.…”

“…A significant increase in antioxidant status was observed following consumption of strawberries or other berries in various postprandial or long-term interventions (reviewed by Basu et al [12]). However, Zunino et al [20] found no significant increase in antioxidant status after FDS supplementation for 3 weeks. In this crossover study, 20 obese subjects were randomly assigned to the strawberry powder or control intervention for 3 weeks.…”

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

“…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).…”